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A65 bearings yet again...
#794567 01/01/20 6:17 pm
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A65 bearing and rod issues have been discussed over and over on here, and other forums, on club nights, garages and sheds, rallies, and so on.
Blood has been drawn! This is clearly no trivial matter!

From what we've seen on a few high mileage engines with dropping oil pressures, one bearing shell on the drive side has started deteriorating.
A friend is working on one such engine just now.
Just as per Tridentman's recent post actually.
As discussions do, the thread wandered off a bit, but to re-cap:

Are the drilled rods really prone to breaking from the oil hole? These are the steel cap type.
Will a plugged oil hole lead to untold damage to the cylinder and/or main bearing? Many seem to have done this with no issues.
Does the very minimal pressure drop from when the bearing passes over the oilway affect lubrication very much at all?
Are new bearing shells from say SRM better wearing than the white metal originals?

The engine in question has an SRM oil pump and OPRV, and is sound in every way except for that single bearing shell and a very lightly scored journal, which may be ground.
It's a road bike, sensibly used and in good shape over all.
I'm thinking that I'd use the engine with no further mods than uprated bearings, except maybe for peening the oil hole in the rod shut.

What do you, the A65 experts say?

SR

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Re: A65 bearings yet again...
Stein Roger #794571 01/01/20 6:40 pm
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on alloy you will do damage to the grain structure of the material by peening the hole closed bad bad idea imo

the bsa engineers seemed to think the hole was a good idea....so do i

ive seen a few broken rods but dont believe they had anything to do with the hole

if you are a mathematical fellow do a calculation of the cross sectional area of the rod at the hole part them calculate the area of the hole and figure out what % of the area has been removed by the hole its minuscule



"There's the way it ought to be and there's the way it is" (Sgt Barnes)
Re: A65 bearings yet again...
Stein Roger #794573 01/01/20 6:51 pm
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"Will a plugged oil hole lead to untold damage to the cylinder and/or main bearing?"
no. Not at all.
my bike ran for years with the drive side rod oil hole plugged, it didnt break, and it still has the same mains. Bore wear did happen, but not because of this, no air filters was the reason. This on an end fed crank 750.
The std set up with the Timing side bush is a different matter, as the bush wears the drive side big end is the first to suffer.


71 Devimead, John Hill, John Holmes A65 750
56 Norbsa 68 Longstroke A65
Cagiva Raptor 650
MZ TS 250
The poster formerly known as Pod
Re: A65 bearings yet again...
Stein Roger #794576 01/01/20 7:51 pm
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Thanks for the input!

Ignoramus, IMHO peening might even be a good thing, rolling over the edge of the hole and inducing compression in that area.
But your concern is a viable one and will be taken into the discussion. The tiny reduction in cross section is of no consequence, I agree.
There are other ways to plug the hole too of course.

Gavin, you, along with Mark Parker and others have had the same experience, and the mileage to back it up too.
If it was my engine I don't think I'd bother though, in a sound but standard engine, that is.
I can't imagine the minuscule squirt lasting a tiny fraction of a second 2 times per revolution would have any impact on the hydrodynamic wedge in the bearing.
I don't have numbers but the oil inside the crank cavity creates a lot more pressure from centrifugal forces than you see on the oil pressure gauge.
That is unless the cavity is less than full, which would happen with a poor pump, leaking OPRV, and worst of all a sloppy main bearing. Different scenario.
Kommando says the original bearings were white metal and not what he'd have specified for a relatively high powered engine.
I'm thinking modern bearings may make a big difference.

My friend the engine builder has done most of the A65 plain mains around here. He's adamant that with a decent oil pump and OPRV (he favors SRM) a standard engine will run forever.
He makes and line-reams the bearings himself, as well as grinding the journals.
"Forever" in this context would mean well over 100.000 km I guess.

Re: A65 bearings yet again...
Stein Roger #794579 01/01/20 8:23 pm
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like all good analogies/metaphors it was simply to illustrate a point Allan ......not to be dissected , i am well aware of why the hole is there but maintain that the BSA engineers who knew more about the matter than you or I put it there for a reason........what i fail to see is why anyone would blank it off ...and yes i am aware that the early ones didnt have it.


"There's the way it ought to be and there's the way it is" (Sgt Barnes)
Re: A65 bearings yet again...
Stein Roger #794584 01/01/20 9:19 pm
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You may have noticed that I actually removed the post before you had placed yours. My point however wasn’t to nit pick what you wrote, it wasn’t a good metaphor at all and read the wrong way would give someone the wrong idea, but I don’t think you got my point. Most importantly the oil hole is only there to help spray oil up the cylinder, it has little bearing on the oil flow across the journal.


Now let’s all have a beer beerchug

68’ A65 Lightning “clubman”
71’ A65 823 Thunderbolt (undergoing restoration)
67’ D10 sportsman (undergoing restoration)
68’ D14 trials (undergoing transformation)

Re: A65 bearings yet again...
Stein Roger #794588 01/01/20 9:39 pm
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Allan : "t I don’t think you got my point. Most importantly the oil hole is only there to help spray oil up the cylinder"

i know that is why it is there .......and no i didnt see you remove your post

But in the interests of clarity i have also amended my comment

one poster has a tag line "there are no bosses in technical discussions" ...........i do like that one


"There's the way it ought to be and there's the way it is" (Sgt Barnes)
Re: A65 bearings yet again...
Stein Roger #794590 01/01/20 9:50 pm
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What year engine? Before I make any more comment, that would be good to know


Never underestimate the human ability to elevate stupid to a whole new level!.
Re: A65 bearings yet again...
Stein Roger #794597 01/01/20 11:48 pm
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This whole thing has come up before. Popular theory , which is what I believe, you can take with a tiny pinch of salt if you want , is that early motors suffered due to random sparks from the 4 CA breaker systems, , in an attempt to solve the overheat and sometimes terminal engine failure caused by the random sparks, BSA increased the oil flow through the crank with the hole to help with cooling, it wasnt till the 6CA plate came in that the problem was cured directly. The hole was maybe a solution to a problem that was really a bad spark thing.

Last edited by gavin eisler; 01/01/20 11:49 pm.

71 Devimead, John Hill, John Holmes A65 750
56 Norbsa 68 Longstroke A65
Cagiva Raptor 650
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Re: A65 bearings yet again...
Stein Roger #794599 01/02/20 12:17 am
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Gavin : "BSA increased the oil flow through the crank with the hole to help with cooling, "

exactly the point i was trying to make earlier regarding oil FLOW, however since my comment wasn't widely appreciated i removed it in the interest of harmony


"There's the way it ought to be and there's the way it is" (Sgt Barnes)
Re: A65 bearings yet again...
Stein Roger #794618 01/02/20 11:12 am
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Quote
Will a plugged oil hole lead to untold damage to the cylinder and/or main bearing?


The main bearing does not need much oil as its rolling element, the cylinder probably does not need the oil but you can give it extra oil without the hole'

[Linked Image from i.postimg.cc]

Quote
Does the very minimal pressure drop from when the bearing passes over the oilway affect lubrication very much at all?


The oil film thickness is the critical factor inside a plain bearing, the pressure inside this oil film is many times greater than the oil pressure shown on a gauge but not easily measured. The oil pressure gauge is just confirming your clearances are correct to give the right amount of oil for the oil film in the plain bearing to stay in place and not fail resulting in metal to metal contact and rapid wearing of the plain bearing. So its a proxy reading not a direct reading of what you need to know. What is more worrying about the hole in the drive side top shell is its location at the exact point the pressure from combustion is highest and the oil film needs to stay in place, it reduces the area of the oil film at exactly the wrong point and just this alone says it needs eliminating.

Quote
Are new bearing shells from say SRM better wearing than the white metal originals?


Yes they are, never fit Whitemetal, but for a road bike the SRM are overkill and the overlay layer wears out quicker than the Al/Sn alternatives, but if you use the Al/Sn then you also need to fit an oil filter in the return oil line.

Re: A65 bearings yet again...
Stein Roger #794654 01/02/20 10:55 pm
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The steel capped rods i've seen had no oil holes.
My own original '72 a65 has no oil holes in the ds rod. (from the factory)

The normal reason for the drive side big end bearing giving up is lack of
oil due to worn ts bush, this is normally due to no oil filter being fitted or
infrequent changes.
I've built a few over the years with various configs, the oil holes didn't seem
to give problems, if you don't want the oil hole , fit a blind shell that side.

From about 1992-2014 there were only aluminium tin shells available new.
All the tri-metal types were old stock and hard to find. Al-tin are fine.

Last edited by NickL; 01/05/20 12:28 am.
Re: A65 bearings yet again...
Stein Roger #794685 01/03/20 9:06 am
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Thanks to all!

It's a late engine, I believe the engine # started with GD, which would make it a 70 I think? I haven't seen the bike and I can't say if has a proper filter fitted.
The rods are steel capped but with holes. I talked to my friend on the phone yesterday (it's a senior thing, actually talking on the phone) and he had peened the holes shut.
I'm used to Triumphs who never bothered with oil spray holes that I know of, and cylinder lubrication has never been a problem. The A65 system appears largely identical.
The shells will be supplied by Classic Motorcycles, the best parts source in Scandinavia. What brand they are, and whether oil holes or blind remains to be seen.
Fot it's sins, I haven't seen a tendency on a Triumph crank to wear one set of shells faster than the other, or much at all, even if people sneer at its archaic oil pump.
A65 bearings seems to wear faster on the DS, and they do so for a reason. Not knowing these engines that well, I still have opinions though and I believe A65s were let down by poor oil pumps, leaky OPRVs, and white metal shells.
The shells on this engine bore evidence of plastic deformation. Why this happens sooner on the DS is the question. Could it be due to the spray hole, or is it an oil distribution thing in the crank? This particular engine has SRM pumps and OPRV but wasn't born with them, so the damage to the shells may have started earlier.

My opinions and thoughts are based on my association with people suffering A65s for decades, and on what I've found in magazines and on forums.
I do therefore realize my opinions to be of little value in this context, but if I was to embark on a project, these things are what I'd concentrate on.
I believe the A65 to be a sound design, let down by a few sub-standard components.
A friend (yes I have more than one!) has got a genuine Lightning Clubman buried deep in his garage, I may want to help him with that...

PS. Clarification; the TS rod has no holes, while the DS one has two.
Inspected the bearings today, and the shells are of the VP variety. The TS pair looks good for more miles while the DS big end journal is worn 2 thou.
Both shells looked much like the one in Tridentman's post.
The main bushing is a little sloppy as well, though the journal appears to have stood up well. It will ground for roundness and a bushing made to suit.

SR

Last edited by Stein Roger; 01/03/20 3:27 pm. Reason: Added info.
Re: A65 bearings yet again...
Stein Roger #794691 01/03/20 2:50 pm
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Quote
The shells on this engine bore evidence of plastic deformation. Why this happens sooner on the DS is the question. Could it be due to the spray hole, or is it an oil distribution thing in the crank?


These engines were all designed before the computer software for modelling oil film thickness was written. Once it was written and all the crank/bearing parameters entered then you could see where the issues were going to be and change the parameters to get equal flows and pressure at both big end journals. Even without this software the evidence on all the twin engines (BSA.Norton and Triumph) show the driveside to have greater wear issues than the timing side. The solution is to first either move the hole in the shell to the lower shell or eliminate it completely plus changing the relative sizes of the hole in the big end crank journals so the flow of oil into both big ends was equal. That would then leave you with the initial start whereby the oil will always get to the timing side first, so the driveside is always going to suffer from this issue, maybe a 10/50 instead of a 20/50 would work here. I certainly use a 10/60 fully synthetic in my Commando engine, the magnetic drain plug on all the previous 20/50 dino oils furred up every oil change but since going to the 10/60 there is no fur at all, is that due to the synthetic oil or the quicker flow on cold starts or both ? .

Re: A65 bearings yet again...
Stein Roger #794695 01/03/20 3:07 pm
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Perhaps one of the other factors causing plastic deformation is the temperature of the bearings.
As well as lubrication the oil serves the function of cooling the bearing.
I have never measured temperatures in the two (timing side and drive side) big end bearings but because the oil travels first to the timing side first then the drive side I would have thought that the drive side bearing sees higher temperatures and that this could cause more plastic deformation/deterioration of the bearing material?
Would very much welcome Kommandos comments on this--he is a bearing expert---I am just a simple thick heat transfer guy.

Re: A65 bearings yet again...
Stein Roger #794697 01/03/20 3:23 pm
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For Whitemetal at least, being a soft and also low melting point material, then a lower oil flow will cause it to deform from higher heat, but that could be due to the oil film collapsing and heat being generated from metal to metal contact. The whitemetal is so soft and compliant the steel crank journal will be untouched so no clues such as a blued crank to show which one is the cause.

Re: A65 bearings yet again...
Stein Roger #794701 01/03/20 5:39 pm
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Thanks for the info John!

I occasionally copy and paste technical info from this and other forums for my own "Book of Knowledge" I keep. Just random tech information about mainly bikes that I have accumulated for years. Recently, I have only been infrequently saving anything.


But, with all of the bearing info that has been shared, it was time to expand the book.

Thanks again!

thumbsup

beerchug


Never underestimate the human ability to elevate stupid to a whole new level!.
Re: A65 bearings yet again...
kommando #794708 01/03/20 8:04 pm
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Originally Posted by kommando
Quote
The shells on this engine bore evidence of plastic deformation. Why this happens sooner on the DS is the question. Could it be due to the spray hole, or is it an oil distribution thing in the crank?


These engines were all designed before the computer software for modelling oil film thickness was written. Once it was written and all the crank/bearing parameters entered then you could see where the issues were going to be and change the parameters to get equal flows and pressure at both big end journals. Even without this software the evidence on all the twin engines (BSA.Norton and Triumph) show the driveside to have greater wear issues than the timing side. The solution is to first either move the hole in the shell to the lower shell or eliminate it completely plus changing the relative sizes of the hole in the big end crank journals so the flow of oil into both big ends was equal. That would then leave you with the initial start whereby the oil will always get to the timing side first, so the driveside is always going to suffer from this issue, maybe a 10/50 instead of a 20/50 would work here. I certainly use a 10/60 fully synthetic in my Commando engine, the magnetic drain plug on all the previous 20/50 dino oils furred up every oil change but since going to the 10/60 there is no fur at all, is that due to the synthetic oil or the quicker flow on cold starts or both ? .

It would seem that many little design and manufacturing errors sometimes stacked up against the poor A65.
To recapitulate a few counter measures:
Journals ground to spec.
Correct bearings used, no white metal. Correct shimming and line reaming is a given,
Steel cap rods, or custom ones, sans the oil hole.
Enlarge the journal oil ways on the DS a safe amount.
A decent, and tested, oil pump, and OPRV.
Use a good 10/60 synthetic oil for safer cold starts.
Add a good return filter.

How does that sound kommando?

Let me add one thing maybe not discussed often enough; don't lug these engines. It's a killer.

SR

Re: A65 bearings yet again...
Stein Roger #794712 01/03/20 9:30 pm
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Most definitely don't lug an A65! it kills them. They like to rev.

If that is a true 70 engine, it "should" have the revised drilling for the drain oil at the OPRV. Early engines used an angle drilling into the sump, late engine were a straight shot to the suction line from the sump to the return side of the pump. The casting was revised on the late cases to make it possible.

The angle drilling cases were all over the place on separation between OPRV drain and the pressure side from the pump. I have seen cases that have had 2 or less threads to make a seal. That is a pretty critical area to have minimal seal.

Late cases are better. But, what are they using for a seal between the OPRV and the cases? it should e a very thin washer (1/32", 0.8mm) if I remember right. Some gasket sets & replacement seals for the OPRV are 1/8" (3mm) or so. Not good, as it raises the OPRV too high and the pressure side can bleed into the drain side.

I actually prefer to lightly chamfer the mouth of the OPRV cavity and run a thin O-ring as the seal. Just make sure it doesn't bottom out in the cavity


Never underestimate the human ability to elevate stupid to a whole new level!.
Re: A65 bearings yet again...
Rich B #794716 01/03/20 10:06 pm
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Originally Posted by Rich B



Late cases are better. But, what are they using for a seal between the OPRV and the cases? it should e a very thin washer (1/32", 0.8mm) if I remember right. Some gasket sets & replacement seals for the OPRV are 1/8" (3mm) or so. Not good, as it raises the OPRV too high and the pressure side can bleed into the drain side.



Good info and something I didn’t know. Does this thickness washer apply to all engines?


Now let’s all have a beer beerchug

68’ A65 Lightning “clubman”
71’ A65 823 Thunderbolt (undergoing restoration)
67’ D10 sportsman (undergoing restoration)
68’ D14 trials (undergoing transformation)

Re: A65 bearings yet again...
Stein Roger #794721 01/03/20 10:32 pm
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The best fix for an A65 is an end fed crank, ball located , no thrust issues , more oil to big ends. Les Mason knew a thing or two Wonderful . and before you say plain bushes are OK look at the size of a BMW plain bush R series and compare to BSA. The thread that precedes just adds fuel to the fire.
buying a Devimead in 1981 has convinced me, apart from the end feed mods its BSA crank, rods , cams, pistons and ile pimp, YMMV. theres a good bike in there just waiting to get out.


71 Devimead, John Hill, John Holmes A65 750
56 Norbsa 68 Longstroke A65
Cagiva Raptor 650
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Re: A65 bearings yet again...
Stein Roger #794723 01/03/20 10:42 pm
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The fuel fitting for a Holley carb uses a thin metal washer, and fits the OPRV.


1968 BSA Firebird
1200 HD
XS 1100
1972 Rickman 125
Re: A65 bearings yet again...
Stein Roger #794727 01/03/20 11:11 pm
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Lets look at how the stock shystem might work , oil at pressure enters the timing side bearing, BSA provided a shelf on the crank side to prevent oil from this bearing spraying up the t/s of the the bore wall, no need for oil cooling to the bore here it would seem .

The crank is spinning at start up in a sump full of oil , throwing oil everywhere, .the cam bushes rely on this , and they dont wear out , significantly so that works OK.

oil in the crank centre passage that has made it past the timing side bush leak , goes to the timing side big end, some squirts out, whats left goes to the drive side, if theres a hole in the shell that lines up with the rod the oil pressure wedge has gone ,

at operational speeds there will be a general thick emulsion or miasma of combustion gases and oil concentrated on the timing side which gets 2/3 of the oil pumps output, 1/3 from the bush, 1/3 from the timing side big end , possibly why the drive side inlet cam is the first wear.

While all this sturm and drang is goin on the oil pump is doing its best to empty the sump, once it does , less oil is thrown around , the lack of oil scraper on the whipping flywheel encourages spray to the cams,
cool oil to the TS bush gets sliced by the crank spinning round then fed and warmed again before meeting the drive side big end.
Its only a wee oil pump. Look at any other oil pump from a bike bigger than a 500.
The moral of the story is , if you dont have a 4ca breaker plate fit your drive side big end shells so the hole is covered and live on, if you do have a 4ca plate it wont matter , your engine is going to fail soon , one way or another ( and, get an end fed crank , if you want to live happily ever after).

Edit, this is probably the third or forth i I have typed this sort of pro end feed prose, I cant stop myself, all the other end feed guys will be reading this and thinking smugly ,
yeah,
then all the timing side bush guys are goin
naw,
thats not strictly adequate, well neither is the stock bush set up, its pish. Yeah fit a filter , its still pish, try finding an original steel backed bush, maybe fit some " bronze". euch find a 10 dan machinist to hit that 0.0015 sweet spot. Sure every back yard cheap do it upper can do that.
re edit, this not aimed at you Stein, Im sure your guy goes up to eleven. just ranting.


Last edited by gavin eisler; 01/03/20 11:47 pm.

71 Devimead, John Hill, John Holmes A65 750
56 Norbsa 68 Longstroke A65
Cagiva Raptor 650
MZ TS 250
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Re: A65 bearings yet again...
gavin eisler #794733 01/04/20 12:09 am
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Originally Posted by gavin eisler
Lets look at how the stock shystem might work , oil at pressure enters the timing side bearing, BSA provided a shelf on the crank side to prevent oil from this bearing spraying up the t/s of the the bore wall, no need for oil cooling to the bore here it would seem .

The crank is spinning at start up in a sump full of oil , throwing oil everywhere, .the cam bushes rely on this , and they dont wear out , significantly so that works OK.

oil in the crank centre passage that has made it past the timing side bush leak , goes to the timing side big end, some squirts out, whats left goes to the drive side, if theres a hole in the shell that lines up with the rod the oil pressure wedge has gone ,

at operational speeds there will be a general thick emulsion or miasma of combustion gases and oil concentrated on the timing side which gets 2/3 of the oil pumps output, 1/3 from the bush, 1/3 from the timing side big end , possibly why the drive side inlet cam is the first wear.

While all this sturm and drang is goin on the oil pump is doing its best to empty the sump, once it does , less oil is thrown around , the lack of oil scraper on the whipping flywheel encourages spray to the cams,
cool oil to the TS bush gets sliced by the crank spinning round then fed and warmed again before meeting the drive side big end.
Its only a wee oil pump. Look at any other oil pump from a bike bigger than a 500.
The moral of the story is , if you dont have a 4ca breaker plate fit your drive side big end shells so the hole is covered and live on, if you do have a 4ca plate it wont matter , your engine is going to fail soon , one way or another ( and, get an end fed crank , if you want to live happily ever after).

mine did wear out eventually , it took most of a lifetime and it was fecked when I got it.



Can't agree with a lot of your thoughts Gavin, the pump is not much smaller than a norton's.
There are hundreds of a65' +a50's out there that have standard bushes fitted.
Where the failing was mainly was no oil filter plus the majority of the bikes were sold in the 'states
where they were a cheap toy so little maintenance was done. Ball and roller races are ok with that
bush arrangements are not.
Whilst the end feed setup is a better idea many people don't like the use of a needle roller instead of
a proper roller bearing. I am not a fan of the use of the combination type bearing used by the main
converter of these motors. The actual load capability of the steel housed bush is greater than the needle race.
A lot of people don't like the idea of running a thin walled needle race in aluminium and say a steel sleeve should
be used. I'm not knocking it but the *** conversion is not the be all and end all of engineering in many people's
opinion. No circlip on the feed seal for instance. It was designed by Mr Mason as a compromise, BSA would
not change the casting to accommodate a ball or roller race.
The end feed setup is often used as compensation for people's inability to do the original job correctly.
I've done several over the years, indeed i have one on my bench at the moment with an end-fed A10 crank fitted
the main reasons i end fed/needle converted this one is that the customer was convinced it was better and the crank
main journal was stuffed anyway. I still don't use the combination needle race though.
The pump on a 650 triumph for instance is the same as it's 500 brother and the 750. Over the years they expanded
and if they were in production now they would probably have a deeper timing cover to accommodate the
2 inch bore piston pump further upgrades would require......
Dave Madigan came up with the best a65 oil pump solution i've ever seen but no-one was interested.
Much better than a reproduced identical aluminium gear pump.

I still say, put together properly with a good oil filter and standard bush these motors are good for over 50k miles.
That's all you could expect from any of it's cousins without a fairly major overhaul.

Re: A65 bearings yet again...
Stein Roger #794735 01/04/20 12:35 am
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Good to hear ya Nick,
"The end feed setup is often used as compensation for people's inability to do the original job correctly."

Thats exactly where I fit in, some guy in a shed trying to keep his bike running. . Hard works no easy, and easy works hard to find.

I looked an an XR750 stlylee HD oil pimp the other day for a Buelll , it was like comparing a Hare to a Rabbits heart HD to BSA
the hD was twice as wide , twice as high. it cost two arms and a leg. add a zero to SRMS pump.

Last edited by gavin eisler; 01/04/20 1:18 am.

71 Devimead, John Hill, John Holmes A65 750
56 Norbsa 68 Longstroke A65
Cagiva Raptor 650
MZ TS 250
The poster formerly known as Pod
Re: A65 bearings yet again...
Stein Roger #794737 01/04/20 1:17 am
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It's little more than a hobby for me Gavin, but i've got a couple of guys who can machine stuff well
and i have some experience with the a65's so as a combination it works. As long as blokes don't
want the engine in 20 minutes and can stand dealing with this obnoxious old ghit, i'll do 'em.

David's oil pump used the inner of a suzuki pump and was costed out at less than the *** one.
The relief side on the bike would have needed beefing up to cope as the pump was miles more efficient.
A bleed to the rockers etc. A proper job, not just a copy of the original.
I'm saying this in the hope that he will resurrect the project and start making 'em.

As for the HD pump, of course it's bigger, its American. Is it better though?????



Last edited by NickL; 01/04/20 1:22 am.
Re: A65 bearings yet again...
Stein Roger #794738 01/04/20 1:30 am
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A bigger pump would be the ticket, but ,its a tight space.
For me its been a lifetime, crashed my Tbolt in 79, had the devi ever since 81 , served me well, the t bolt had a fucked TS bush, still ran fine till the end. nobody cared about oil pressure back then, it either ran or it didnt.
I think what kills A65s is not running, cold starts, bad timing and museuming if thats a word, they need ridden to keep working.
And
Happy New Year,


Last edited by gavin eisler; 01/04/20 1:38 am.

71 Devimead, John Hill, John Holmes A65 750
56 Norbsa 68 Longstroke A65
Cagiva Raptor 650
MZ TS 250
The poster formerly known as Pod
Re: A65 bearings yet again...
Stein Roger #794740 01/04/20 1:53 am
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Roughly what does it cost to have an end feed conversion done?
Not that I'm considering it on the current bike. I'd spend on a Newby belt drive first.


1966 BSA Lightning
(2) 1967 Triumph "Choppa"s
1974 Indian ME125
1960 Harley Servi-Car
Re: A65 bearings yet again...
gavin eisler #794741 01/04/20 1:58 am
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A better design may be the answer rather than a bigger pump.
David's device was driven at 50% engine speed rather than 33%. i think.
The rotors were of the Gerotor type rather than gears etc.
The pump doesn't have to be bigger to be far better. (don't just think American!)

Re: A65 bearings yet again...
Nick H #794742 01/04/20 2:00 am
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Originally Posted by Nick H
Roughly what does it cost to have an end feed conversion done?
Not that I'm considering it on the current bike. I'd spend on a Newby belt drive first.


Talk to EV Engineering if you're in the 'states.

Re: A65 bearings yet again...
Stein Roger #794744 01/04/20 2:13 am
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About a grand for the end feed last time I looked UK, more like two once other stuff gets added.

, trying not to think Murkin, agreed something neater than a Buell pimp would be do able.


71 Devimead, John Hill, John Holmes A65 750
56 Norbsa 68 Longstroke A65
Cagiva Raptor 650
MZ TS 250
The poster formerly known as Pod
Re: A65 bearings yet again...
Stein Roger #794750 01/04/20 2:35 am
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Blimey,,,,,,,,,,,,,,,,,,,,, i will have to revise my prices.
I'm still charging 500 Guineas. (mind you, i insist on the gold coins.)

Re: A65 bearings yet again...
Stein Roger #794759 01/04/20 10:26 am
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Quote
How does that sound kommando?


I have never owned an A65, my list is based on general Brit Twins plus a few pointers from the A65 ie BSA/Vandervell's odd decision to use whitemetal.

The end feed option is attractive, it eliminates all the oil loss from the timing bush and redirects it to the big ends without needing an up-rated pump, but like the bush it replaces its at the margins of the design parameters unlike the full ball/roller bearings used on the Norton and Triumphs. Norton never used a timing bush, Triumphs did initially on the Unit 350/500 and took the derision to change it to a ball bearing 68/69, BSA did the same change on the Unit singles in 66 but never on the A65.

Re: A65 bearings yet again...
Stein Roger #794760 01/04/20 10:43 am
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Rich B, thanks for the info on OPRV and oil-ways. This is a genuine 70 with the raised engine no pad with BSA embossed on it. I'll have a look when I pop in maybe later today.

I too think end feed and a rolling element bearing is better. Triumph and Norton rarely have these particular issues, except on the C-series Triumphs. They displayed some of the same problems with wear as the A65, but kept their ball bearing DS, so never had the axial play problems. As we know, Triumph still felt forced to to something about it.
However, the cost of such conversions is an obstacle for most owners, most of whom rides their P&J infrequently.
And yes I agree, that's a big factor too. "Museuming", I like it :-)
As a side comment; triples displays much of the same as the A65, though to a lesser degree. As we know, the crank is fed in the exact same way as the A65, only through two plain bearings. These are in my experience prone to premature wear too, but can be changed with the engine still in the frame. I did mine when I overhauled the top end. The bearing material was worn away completely.
Some say nitriding the journals will add life to both journal and bearing. I don't know. That's one for kommando I think.

Pump size... engineers knows the requirements and will size the pumps accordingly, with a reserve. The A65 wasn't the first plain bearing motor ever built and the knowledge were there, tables available and expertise to draw on. It's when the quality of the pumps, alignment of oil ways, well the precision of everything, deteriorates, the biggest oil pumps won't save an engine.
The central flywheel cranks will whip a bit, and worse with increasing speed. I think my friend (Chief Engineer by profession) may have a point when he says an A65 should run low compression pistons, be kept over 3000 rpm for proper oil flow, and under 5000 for longevity. But where's the fun in that?

Oils and filters are important. Most old bikes I know of seems to run on 20-50, as I indeed use to recommend.
Like kommando, I did run my Trident on 10-60 synth until it burned it off so quick I couldn't afford it.
I will revert to this know that I have normal oil consumption, in the light of kommando's experience. If I ran an A65 I'd seriously consider the same.
"Museuming" will eventually let the oil film dry up and oxidize, which is a bad thing. Except for the fact that an A65, or most Brit bikes in fact, will fill their cases with oil, which is good for the crank, less so for the cylinders and top end. Wear will happen, and steel fragments will contaminate the oil, so a proper oil filtering system is vital. Many hold the opinion that frequent oil changes will suffice. On a frequently used bike, maybe, but why not use a proper filtration system anyway.

I've learnt a lot from you guys. Thanks to each and everyone of you!

SR

PS. kommando replied as I was writing that. Thanks! Which 10-60 oil is it you use?

Last edited by Stein Roger; 01/04/20 10:47 am.
Re: A65 bearings yet again...
Stein Roger #794761 01/04/20 11:32 am
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This is the one, not checked the zinc content for camshaft/follower protection but you can get that separately to add if required.

http://www.millersoils.co.uk/products/0/142

CFS 10W60

Quote
Some say nitriding the journals will add life to both journal and bearing. I don't know. That's one for kommando I think.


As long as the shell bearings last or you catch their failure early then the crank journal life will typically be doubled.

Re: A65 bearings yet again...
Stein Roger #794767 01/04/20 2:00 pm
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Thanks again kommando.

I'm not worried over ZDDP content. Only low friction, fuel saving, catalytic converter friendly types of 0-30 or less do have a lower content, around 800 ppm I believe.
Thicker oils, like 15-40 and up still contain anywhere from 1000 to 1200 ppm. Over 1200 isn't advisable, and I would never add ZDDP to any oil unless I knew the exact specs of both oil and additive.
I know it has been discussed at length on AccessNorton, along with scar tests and such, you may have followed this closer than I did. I don't regard scar tests on motor oils as relevant though, it's like testing a mouse trap with an elephant.

I'm sure the CFS 10W60 vastly exceeds any requirements a sound old Brit Bike would have. I don't know of any stockists around here, but I'll have a look.

SR


Last edited by Stein Roger; 01/04/20 7:09 pm. Reason: Grammar, but probably wrong anyway.
Re: A65 bearings yet again...
Stein Roger #794797 01/04/20 9:58 pm
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The triple does not have the oil feed problem of the A65 because it has a four bearing crank. An A65 crank whips from the offset weight in the middle with bearings spaced far apart on either side. The whipping tilts the crank in the bearing which makes supporting the oil film across the bearing near impossible.
Alternatives are moving the counterbalance to the outer webs where the bearings are or support the crank in the middle. End feeding the crank and using a needle bearing is a half way measure. NTN gives an inclination tolerance of 1/2000 for a radial needle bearing (pg A39 http://www.ntnamericas.com/en/websi...edle_roller_bearings_2300-vii_lowres.pdf). That is 0.0005" for a 1" bearing.
The stock setup would last longer with more oil to compensate for the loss.
According to a GM study on main bearing caps, the main cap shells should not be grooved. There is an increase in the load per area across the two shell lands compared to a ungrooved shell. No [***] Ollie. There is less surface area with a groove on same width bearings. But oil has to be fed into the crank and having half the feed time closed off disrupts the flow to the rods. Maybe GM did not take that aspect into account.

Re: A65 bearings yet again...
Stein Roger #794798 01/04/20 10:53 pm
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Seem to remember seeing some main bearings with grooves on the back, this allowed the oil to still flow to big ends but stay full width bearing material.

Re: A65 bearings yet again...
Stein Roger #794807 01/04/20 11:56 pm
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So all the best advice for running an a65 comes from people who've never owned or run one eh?
You lot should go into politics.

Sorry chaps but that's how it's looking.

Re: A65 bearings yet again...
Stein Roger #794813 01/05/20 1:37 am
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.
what every a65 really needs is
oil dippers on the rod caps .
.

Re: A65 bearings yet again...
quinten #794829 01/05/20 8:31 am
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Originally Posted by quinten
.
what every a65 really needs is
oil dippers on the rod caps .
.

Another highly experienced A65 owner i suppose????
We've heard 'em all me old cock. Like the ones from the blokes that finished behind me on the the track, and there were plenty of them.
Besides that the lower end modifications required to fit scoops and babbitts on these is harder than an end feed.

Re: A65 bearings yet again...
Stein Roger #794831 01/05/20 10:00 am
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There’s a lot of mention about poor oil flow to the drive side journal because of oil holes etc but no one has yet mentioned the sludge trap that gets plugged restricting oil flow to the drive side journal.


Now let’s all have a beer beerchug

68’ A65 Lightning “clubman”
71’ A65 823 Thunderbolt (undergoing restoration)
67’ D10 sportsman (undergoing restoration)
68’ D14 trials (undergoing transformation)

Re: A65 bearings yet again...
Stein Roger #794833 01/05/20 10:19 am
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Quote
So all the best advice for running an a65 comes from people who've never owned or run one eh?


NickL, I don't run the washing machine, tumble dryer or the dishwasher in the house, do you think I can get out of repairing them using that excuse wink

Re: A65 bearings yet again...
NickL #794835 01/05/20 11:30 am
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Originally Posted by NickL
So all the best advice for running an a65 comes from people who've never owned or run one eh?
You lot should go into politics.

Sorry chaps but that's how it's looking.

Fresh perspective and all that...?

David Madigan's info on grooved bearings is interesting, and we triple owners have looked at the main shells many a time wishing we could dispense with the groove.
But we can't..
On an A65 however, converting to end feed would let you run without the groove, and is something we have discussed.

SR

Re: A65 bearings yet again...
Stein Roger #794843 01/05/20 12:44 pm
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There's a groove on the A65 con rod bearing? Where?


1966 BSA Lightning
(2) 1967 Triumph "Choppa"s
1974 Indian ME125
1960 Harley Servi-Car
Re: A65 bearings yet again...
Stein Roger #794850 01/05/20 1:03 pm
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There's a groove on the A65 con rod bearing? Where?


No there is no groove, the groove was referred to in context of the Triumph/BSA triple engine has main bearings and they have grooves.

Quote
The triple does not have the oil feed problem of the A65 because it has a four bearing crank.


[Linked Image from i.ebayimg.com]

The grooves are to allow the oil to move from the oilways in the crankcase into the crank and then into the big ends through oil galleys drilled into the crank.

Re: A65 bearings yet again...
Stein Roger #794852 01/05/20 1:44 pm
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Stein Roger, as you probably know there are some that has converted a65 to end feed plain bearing using a needle bearing innerring. This way you will get rid of the groove in the shaft and possibly get approx 1/5 more bearing areal. The Guzzi 850 motor has almost identical dimensions (only a few mm longer) as the a65 on the main bearing where the oil is entering and the same groove in the shaft. Never heard of problems with the Guzzis with its short and sturdy crank, so the flexing and oil supply in the a65 is surely to blame.
In my end feed conversioned cranks I use needle bearing NKS 40 (40x55x22 which sits in a thin wall steel sleeve machined into the c.case) with innerring 32x40 which works excellent being the biggest bearing that can be put in there without breaking into the oil channels. A bearing outside the alternator is of course needed for locating the crank axially.


Arnstein

BSA Spitfire MK3.800cc (also engine 850cc 90degree)
Honda CB450T -71
Laverda RGS 1130cc -85
Ducati 1098 -08
Re: A65 bearings yet again...
Nick H #794854 01/05/20 2:06 pm
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Originally Posted by Nick H
There's a groove on the A65 con rod bearing? Where?

Sorry Nick, I was comparing the triple mains and the A65 TS main, but kommando covered that.

David Madigan's comment is valid, the triple crank doesn't whip, but the triples still run their plain mains faster than you'd expect. Something is borderline here, whether it's the bearing line, assembly technique, lubrication, or what have you. It's not uncommon to see worn mains while the big end journals measure up fine. Hence the comparison with the A65 TS main.

I'll be fitting a gauge to my Trident to monitor wear, and maybe change to Millers oil. I've had a look at the type kommando use, it'a a blend of 3 esters and PAO.
This makes it a "true" synthetic, unlike Castrol. Nothing against Castrol, they have served me well, but perhaps the extra protection possibly offered by a true synthetic is just what it takes.
ZDDP is in the 1000-1200 ppm range, which is nice for cams and followers.

I've made contact with a local supplier of Millers, and he seems to know his stuff. Replying to queries on the weekend suggests he's a gearhead too... laughing

But I've side railed myself. Fixing the underlying causes of premature wear and failures is most important, and I thank you all for your input!
I concede that those of you that have actually made these things last, and have proved it too, are the ones I listen the most to.
Like you NickL, you puffed a little back there, but I do take your comments to heart, also in the recent axial play thread! beerchug

SR

Re: A65 bearings yet again...
Arnstein #794855 01/05/20 2:34 pm
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Originally Posted by Arnstein
Stein Roger, as you probably know there are some that has converted a65 to end feed plain bearing using a needle bearing innerring. This way you will get rid of the groove in the shaft and possibly get approx 1/5 more bearing areal. The Guzzi 850 motor has almost identical dimensions (only a few mm longer) as the a65 on the main bearing where the oil is entering and the same groove in the shaft. Never heard of problems with the Guzzis with its short and sturdy crank, so the flexing and oil supply in the a65 is surely to blame.
In my end feed conversioned cranks I use needle bearing NKS 40 (40x55x22 which sits in a thin wall steel sleeve machined into the c.case) with innerring 32x40 which works excellent being the biggest bearing that can be put in there without breaking into the oil channels. A bearing outside the alternator is of course needed for locating the crank axially.

Arnstein, no I didn't know how you did the end feed conversion, but it makes perfect sense. I had forgotten that on an A65 the groove is in the journal, on a C series 500 Triumph the journal is plain and the bearing is grooved. Same results though.
I did know about the outrigger bearing you use on the DS, but it takes it all to a level I'm not even close to, I'm not a toolmaker... My friend the Chief could do it, but I don't think he's interested.
On a standard engine, would you consider a ball bearing to be strong enough on the DS?

SR

Re: A65 bearings yet again...
Stein Roger #794862 01/05/20 4:11 pm
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I think maybe the simplest / cheapest way to make the A65 more dependable regarding crank bearings would be ,as said, to use an innerring (with lubrication holes) meant for needlebearing on the t s together with the original type of steel capped bush and then end feed the crank the easiest way https://1drv.ms/u/s!AsKcYdC1qRK7jQjhEcOLyG9e3Q4n?e=seGmG1
Or, for to avoid bearing outside alternator, do as SRM does and machine in the combination bearing NKIB 5907. I never used the C3 type only the ordinary one but with a retaining ring and the usual interference fit.


Arnstein

BSA Spitfire MK3.800cc (also engine 850cc 90degree)
Honda CB450T -71
Laverda RGS 1130cc -85
Ducati 1098 -08
Re: A65 bearings yet again...
Stein Roger #794869 01/05/20 4:35 pm
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Thanks for the pic, neat installation which avoids all the welding and drilling other people seem to do.

SR

Re: A65 bearings yet again...
Stein Roger #794873 01/05/20 5:02 pm
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Not to diverge from the A65 issue but the high wear rate of triple mains is likely from assembly. Assuming the crank mains have been measured and in line, the centre mains are aligned with the end roller and ball bearings with two dowels on each side. If these dowels were a precision fit it would be difficult to mount the cases together since they would have to be dead square to go together. The mains clearance is 0.0005" - 0.002" which is probably the clearance of the dowels in the case. The only way to get close to alignment is to mount a flat plate across the cylinder joint and tighten it along with the case bolts. That only aligns the vertical misalignment. There is nothing to correct the horizontal except the crank.

Re: A65 bearings yet again...
DMadigan #794880 01/05/20 6:40 pm
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Originally Posted by DMadigan
Not to diverge from the A65 issue but the high wear rate of triple mains is likely from assembly. Assuming the crank mains have been measured and in line, the centre mains are aligned with the end roller and ball bearings with two dowels on each side. If these dowels were a precision fit it would be difficult to mount the cases together since they would have to be dead square to go together. The mains clearance is 0.0005" - 0.002" which is probably the clearance of the dowels in the case. The only way to get close to alignment is to mount a flat plate across the cylinder joint and tighten it along with the case bolts. That only aligns the vertical misalignment. There is nothing to correct the horizontal except the crank.

Yes I think you're right. It's definitely not the best design possible, and easy to screw up. It requires fitting skills rather than assembly skills, which is doomed to fail on an assembly line.
I have my thoughts on thermal expansion as well, the center section may possibly grow faster as it heats up, pushing the mains up and out of center. But that's purely speculation.
I always take care to warm the engine up good before gunning it. As I do with any engine, but some engines are more sensitive, like the A65 for example.

SR

Re: A65 bearings yet again...
Stein Roger #794906 01/05/20 10:36 pm
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DS ball bearing was used with success by one of Marcs on this forum, now is used by Allan Gill ( if my memory serves me right ) and I'm building another one. My former A65 was used with stock arrangement of bearing for 10 years and perhaps 25000 km with not a hiccup and is used by the new owner in Calgary, who called me last summer to tell me how happy he is with the bike working still like it should.
So even with stock configuration, but regularly maintained these bikes are reliable as regular street bikes.
Only improvements made to this engine were iron oil pump, charging system with solid state reg/rec, oil filter in return line and Boyer ignition. Timing side bush was solid bronze and I believe installed without line boring, but giving good pressure ( no flickering light on idle on hot engine ).
And because of changing its cylinder head to small port version I was able to take it above 7k revs on lower gears more than couple times, closing a tacho ones on third for a second. So yes this bike was ridden quite hard and survived it.
I write all this to say - don't overthink it, I found a Trident much more difficult and fragile bike comparing to old trusty A65.

Re: A65 bearings yet again...
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Originally Posted by kommando
Quote
So all the best advice for running an a65 comes from people who've never owned or run one eh?


NickL, I don't run the washing machine, tumble dryer or the dishwasher in the house, do you think I can get out of repairing them using that excuse wink



I'm only having a laugh, same with Stein Roger.

It's just that over the years i've heard so much stuff about how crap the A65 bottom end is and how they all fail.
I raced a standard 650 and 750 converted bog standard bottom end sidecar for 2 years without touching the bottom end
on an A65. In fact i sold the engine to another bloke who raced it too. That was in a sidecar outfit and was used to 8000rpm
regularly. (I won't mention the transmission and other problems though) Incidentally, we used standard gtx 20/50 oil in that motor.
Yes, when i went to a big motor i end fed it etc but the standard setup on a road bike is adequate. (I feel i've proved that!)
It's interesting also that in the 2 years i raced the bike as a morgo triumph, i broke 3 cranks. It made me feel the A65 was
a far stronger motor overall. (and leaked a lot less oil.)
What sort of mileage do you blokes expect from an engine used normally on the road as a classic? I don't expect more than
30k before a rebuild is required. If you cannot put an A65 bottom end together in standard form that will last 30k, i suggest you
either take it to someone who can or buy a triumph. My road A65T is certainly ridden as hard as my T120 is.
Arnstein's hot-rod is a different case, more engineering effort needs to be put into motors like that, and he certainly has done that.

Last edited by NickL; 01/05/20 11:14 pm.
Re: A65 bearings yet again...
NickL #794952 01/06/20 8:49 am
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NickL OK, an A65 put together right will stand up to racing use and abuse. At least yours did, but it does come down to skilled assembly doesn't it.
The crank held together better than on a Triumph, well with the bigger big ends and shorter stroke, perhaps it should.

Conclusion after this discussion, other forums and articles, talking to people, is that if I were to build an A65 for myself, I'd let the Chief do the bushing, and consider a ball bearing on the DS.
I'd use a tested and certified oil pump and OPRV and perhaps have the crank dynamically balanced. I'd keep the engine otherwise standard.
An OIF A65 won the Classic Cup in Scandinavia years ago, not by being the fastest, but fast enough and always finish.
When I him asked about "the secret" the guy grinned: "it's completely standard, I'm just in it to have a bit of fun".

I have no desire to super tune or big bore an A65, I'll leave that to others. The likes of Mark Parker and Arnstein have proved what's possible, kudos to them.

Thanks again to all.

SR

Re: A65 bearings yet again...
NickL #794953 01/06/20 9:05 am
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NickL, you missed the wink on the end of my comment, I was adding on a twist.

Re: A65 bearings yet again...
kommando #794955 01/06/20 9:17 am
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i was serious about the oil dippers .
the a65 was so close to being a viable engine .
being only sixteen when BSA went out of business
they no doubt had there own reasons
for not answering my emails

Re: A65 bearings yet again...
quinten #794957 01/06/20 9:23 am
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Originally Posted by quinten
i was serious about the oil dippers .
the a65 was so close to being a viable engine .
being only sixteen when BSA went out of business
they no doubt had there own reasons
for not answering my emails

laughing

Re: A65 bearings yet again...
Stein Roger #794958 01/06/20 9:25 am
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Question: Why did BSA change the d s ballbearing to a much more expensive set up with a roller bearing? Because of the roller bearings better load capacity or did they want to spend more money on the A65 without reason?


Arnstein

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Re: A65 bearings yet again...
Arnstein #794968 01/06/20 12:16 pm
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Originally Posted by Arnstein


Question: Why did BSA change the d s ballbearing to a much more expensive set up with a roller bearing? Because of the roller bearings better load capacity or did they want to spend more money on the A65 without reason?

The roller is better but only you and a handful of others need the extra load capacity. The rest are taken to a rally or two in mid summer by riders who never see the north side of 4000 rpm... thumbsup

SR

Re: A65 bearings yet again...
Arnstein #794982 01/06/20 1:59 pm
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Originally Posted by Arnstein


Question: Why did BSA change the d s ballbearing to a much more expensive set up with a roller bearing? Because of the roller bearings better load capacity or did they want to spend more money on the A65 without reason?

I'm doing mine with a roller for both of those reasons. But seriously, I needed a new bearing and the roller just looked so much better.

I recall reading John Healy say something about the switch being due to factory reorganizing and roller bearings being available on the shelf. Something like that.
In other words, I think he implied that it was a practical or economic reason rather than a quality one.
If that is so, they sure went to a lot of trouble remachining the case and changing the crankshaft size to accomodate it.
I'l search for it if John doesn't happen to post on it again.

Last edited by Nick H; 01/06/20 2:53 pm.

1966 BSA Lightning
(2) 1967 Triumph "Choppa"s
1974 Indian ME125
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Re: A65 bearings yet again...
Stein Roger #794985 01/06/20 3:21 pm
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Originally Posted by Stein Roger

The roller is better but only you and a handful of others need the extra load capacity. The rest are taken to a rally or two in mid summer by riders who never see the north side of 4000 rpm... thumbsup

SR


Hardly, Ive had RHP rollers that are loose on the drive shaft after 3000 miles, the RHP ball bearing I have fitted currently is so far is outlasting that. Not saying that the ball is better than the roller but more likely the bearing not made to suitable specification.

I strongly agree that they didn't change to a roller for no reason, however this came at a point where they were also drilling holes in conrods to fix a different problem. As the A10 had roller bearings fitted albeit of a different size (the ID of the A10 roller is much larger than the A65) Im not sure of the OD of that bearing compared though. They knew the A10's didn't have these problems so likely switched back to what they knew worked.


....Just as assumption, I've known several people who use a ball bearing drive side on a 650 without problems. It probably wouldn't hold up to 750cc+ and probably wouldn't last for those people lugging their motor in a high gear.


Now let’s all have a beer beerchug

68’ A65 Lightning “clubman”
71’ A65 823 Thunderbolt (undergoing restoration)
67’ D10 sportsman (undergoing restoration)
68’ D14 trials (undergoing transformation)

Re: A65 bearings yet again...
Nick H #794987 01/06/20 3:27 pm
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Originally Posted by Nick H

If that is so, they sure went to a lot of trouble remachining the case and changing the crankshaft size to accomodate it.



The bearing for ball and roller has the same ID/OD and width of the inner and outer race's as each other, changing bearing type isn't a problem in this instance.


Now let’s all have a beer beerchug

68’ A65 Lightning “clubman”
71’ A65 823 Thunderbolt (undergoing restoration)
67’ D10 sportsman (undergoing restoration)
68’ D14 trials (undergoing transformation)

Re: A65 bearings yet again...
Allan G #794992 01/06/20 4:26 pm
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Originally Posted by Allan Gill
Originally Posted by Nick H

If that is so, they sure went to a lot of trouble remachining the case and changing the crankshaft size to accomodate it.



The bearing for ball and roller has the same ID/OD and width of the inner and outer race's as each other, changing bearing type isn't a problem in this instance.

True but at the time of the bearing change a thrust washer was added, and changes to the crankcase, timing bush, crankshaft counterweight, to account for the roller end float. There is that problem.


1966 BSA Lightning
(2) 1967 Triumph "Choppa"s
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Re: A65 bearings yet again...
Nick H #795008 01/06/20 8:03 pm
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Originally Posted by Nick H
Originally Posted by Allan Gill
Originally Posted by Nick H

If that is so, they sure went to a lot of trouble remachining the case and changing the crankshaft size to accomodate it.



The bearing for ball and roller has the same ID/OD and width of the inner and outer race's as each other, changing bearing type isn't a problem in this instance.

True but at the time of the bearing change a thrust washer was added, and changes to the crankcase, timing bush, crankshaft counterweight, to account for the roller end float. There is that problem.


It depends on the full question or the follow up question. If your using a late set of cases then either bearing will fit with no modification.

If your using it on a early set of cases then your story is different. I haven’t dealt with an early set of cases so I’m not qualified to give opinion, but from what I have seen of the TS Bush, the “thrust face” is steel? You would probably have to make an all bronze Bush thus having a bronze thrust face.... Maybe....

But as I say the bearing size wise isn’t a problem.


Now let’s all have a beer beerchug

68’ A65 Lightning “clubman”
71’ A65 823 Thunderbolt (undergoing restoration)
67’ D10 sportsman (undergoing restoration)
68’ D14 trials (undergoing transformation)

Re: A65 bearings yet again...
Stein Roger #795009 01/06/20 8:05 pm
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It is not a good idea to control end float with a roller bearing, the ends of the rollers will be trying to drill themselves into the lip

Last edited by Andy Higham; 01/06/20 8:06 pm.

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Re: A65 bearings yet again...
Andy Higham #795018 01/06/20 10:16 pm
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Originally Posted by Andy Higham
It is not a good idea to control end float with a roller bearing, the ends of the rollers will be trying to drill themselves into the lip


Information given by INA says that their roller bearings series SL and SL01 are made for to take axial loadings as well as radial.


Arnstein

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Re: A65 bearings yet again...
kommando #795022 01/06/20 10:27 pm
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Originally Posted by kommando
NickL, you missed the wink on the end of my comment, I was adding on a twist.


Ahhh,, you got me there.....................................

Re: A65 bearings yet again...
Allan G #795025 01/06/20 10:39 pm
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(Quote) "Hardly, Ive had RHP rollers that are loose on the drive shaft after 3000 miles, the RHP ball bearing I have fitted currently is so far is outlasting that. Not saying that the ball is better than the roller but more likely the bearing not made to suitable specification."[/quote]



Mr. Gill, are you saying that the rollerbearing came loose on the shaft because it is a roller...and that a ballbearing will not?! To be sure any bearing, roller or ball, not getting loose on a shaft an interference fit is needed, and sometimes a torqued nut, as on A65,

And, as fa as I know the early ballbearing motors did no have any thrust washer. because of the ballbearing it is of course not needed.

Last edited by Arnstein; 01/06/20 10:41 pm.

Arnstein

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Re: A65 bearings yet again...
Stein Roger #795026 01/06/20 10:44 pm
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Originally Posted by Stein Roger
Originally Posted by Arnstein


Question: Why did BSA change the d s ballbearing to a much more expensive set up with a roller bearing? Because of the roller bearings better load capacity or did they want to spend more money on the A65 without reason?

The roller is better but only you and a handful of others need the extra load capacity. The rest are taken to a rally or two in mid summer by riders who never see the north side of 4000 rpm... thumbsup

SR


A good point is also that they were using the same roller bearing in large numbers in the triumph factory as well.
The simple way would have been to have just converted to a double lipped roller that size, if they thought just the
higher load capacity was needed, they changed several things at that time including the crank dimensions and
case castings. It's likely there were other factors behind it as well.

Hey Stein, as for the skilled assembly of an a65 being so critical, i have no mechanical engineering qualifications at all,
the a65 motor we built in 1991 for the outfit was the first a65 engine i had ever seen inside. I bought a set of brand new
unstamped cases complete with main bush and started there. It just went downhill ever since.....................

Re: A65 bearings yet again...
Arnstein #795029 01/06/20 11:00 pm
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Originally Posted by Arnstein

(Quote) "Hardly, Ive had RHP rollers that are loose on the drive shaft after 3000 miles, the RHP ball bearing I have fitted currently is so far is outlasting that. Not saying that the ball is better than the roller but more likely the bearing not made to suitable specification."



Mr. Gill, are you saying that the rollerbearing came loose on the shaft because it is a roller...and that a ballbearing will not?! To be sure any bearing, roller or ball, not getting loose on a shaft an interference fit is needed, and sometimes a torqued nut, as on A65,

And, as fa as I know the early ballbearing motors did no have any thrust washer. because of the ballbearing it is of course not needed.


That’s not what I said, I didn’t say the bearing id became slack because it’s a roller. What I said was it is probably the quality of the inner cage. What I was pointing out is that the ball bearing is perfectly fine, it probably wouldn’t last in your 800/850 motor and I wouldn’t use a ball bearing on my 823 either. There is also no chance the nut came loose on the end of my crank, but thank you for your suggestion.

I had seen a wrongly pictured item for the TS bush, it was probably off an A10 maybe? It appears to have the same cutaways as the later bushes do, looking at the parts books. Still a ball bearing can walk if there is too much end float. You set the end float of the crank against that Bush face and the ball bearing won’t walk. The oil film is probably just enough in this case, unlike the roller where it will constantly kiss the thrust washer or the lip of the outer cage.


Now let’s all have a beer beerchug

68’ A65 Lightning “clubman”
71’ A65 823 Thunderbolt (undergoing restoration)
67’ D10 sportsman (undergoing restoration)
68’ D14 trials (undergoing transformation)

Re: A65 bearings yet again...
Stein Roger #795032 01/06/20 11:25 pm
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Maybe one of the reasons for going away from the ball race and including a ts thrust was that
when the engine is hot, the tendency for the thrust from the oil pump was pulling the drive side
bearing from it's housing.and allowing the crank to move over to the timing side. The natural
thrust of these engines is definitely toward the worm driven oil pump.

Re: A65 bearings yet again...
Stein Roger #795038 01/07/20 12:42 am
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"The natural thrust of these engines is definitely toward the worm driven oil pump" - maybe a case for a spur gear drive oil pump?
Metric roller bearings are available with a separate thrust collar which serves as a second lip on the inner race. Since the single lip on the inner race already provides for the thrust in the drive direction I do not see why the inner race cannot be reversed (lip toward crank) and a thrust collar used on the sprocket side to have the roller bearing take both thrust loads. Solve the whole problem of shimming the crank just as the ball bearing did.
I do not know of any manufacturer that makes them for imperial bearings but it would not be difficult.
One advantage of the Triumph wheeze pump on the camshaft is that it removes any loads on the crank or flex effects on the pump.

Re: A65 bearings yet again...
Stein Roger #795040 01/07/20 12:49 am
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My drive side crank shaft wore where the bearing seats, SRM sleeved it back to size. it had a roller, still does.
my crank had run with a slack rotor nut, maybe that did it.


71 Devimead, John Hill, John Holmes A65 750
56 Norbsa 68 Longstroke A65
Cagiva Raptor 650
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Re: A65 bearings yet again...
Stein Roger #795041 01/07/20 1:03 am
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Doesn't the A65 have a similar breather set up on the end of the cam?


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(2) 1967 Triumph "Choppa"s
1974 Indian ME125
1960 Harley Servi-Car
Re: A65 bearings yet again...
DMadigan #795058 01/07/20 8:38 am
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Originally Posted by DMadigan
"The natural thrust of these engines is definitely toward the worm driven oil pump" - maybe a case for a spur gear drive oil pump?
Metric roller bearings are available with a separate thrust collar which serves as a second lip on the inner race. Since the single lip on the inner race already provides for the thrust in the drive direction I do not see why the inner race cannot be reversed (lip toward crank) and a thrust collar used on the sprocket side to have the roller bearing take both thrust loads. Solve the whole problem of shimming the crank just as the ball bearing did.
I do not know of any manufacturer that makes them for imperial bearings but it would not be difficult.
One advantage of the Triumph wheeze pump on the camshaft is that it removes any loads on the crank or flex effects on the pump.

The ca 1980 upgraded metric size Triumph T140/TR7 timing side bearing is a good example of what you propose David. I think it has proven satisfactory in service by now.
I often wonder why the Norton fraternity won't use this, but persists with a single lip outer either side. Theirs are still called "Superblends", though there's no such thing.
How's that for clever marketing, a standard roller bearing with a catchy name that still sells nearly 50 years on! clap

The Triumph wheeze pump may not be an engineering marvel, with any number of flaws, but in 45 years with these bikes they haven't given me much trouble, so I don't worry anymore. ohno

SR

Re: A65 bearings yet again...
Allan G #795069 01/07/20 12:45 pm
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Originally Posted by Allan Gill
Originally Posted by Arnstein

(Quote) "Hardly, Ive had RHP rollers that are loose on the drive shaft after 3000 miles, the RHP ball bearing I have fitted currently is so far is outlasting that. Not saying that the ball is better than the roller but more likely the bearing not made to suitable specification."



Mr. Gill, are you saying that the rollerbearing came loose on the shaft because it is a roller...and that a ballbearing will not?! To be sure any bearing, roller or ball, not getting loose on a shaft an interference fit is needed, and sometimes a torqued nut, as on A65,

And, as fa as I know the early ballbearing motors did no have any thrust washer. because of the ballbearing it is of course not needed.


That’s not what I said, I didn’t say the bearing id became slack because it’s a roller. What I said was it is probably the quality of the inner cage. What I was pointing out is that the ball bearing is perfectly fine, it probably wouldn’t last in your 800/850 motor and I wouldn’t use a ball bearing on my 823 either. There is also no chance the nut came loose on the end of my crank, but thank you for your suggestion.

I had seen a wrongly pictured item for the TS bush, it was probably off an A10 maybe? It appears to have the same cutaways as the later bushes do, looking at the parts books. Still a ball bearing can walk if there is too much end float. You set the end float of the crank against that Bush face and the ball bearing won’t walk. The oil film is probably just enough in this case, unlike the roller where it will constantly kiss the thrust washer or the lip of the outer cage.






WHY is my answer to mr. Gill deleted? Was it because I pointed out that his sentence.. "what I said was it is probably the quality of the inner cage".. is not to be found in his message (see quote)


Arnstein

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Re: A65 bearings yet again...
Arnstein #795079 01/07/20 5:12 pm
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(quote) I had seen a wrongly pictured item for the TS bush, it was probably off an A10 maybe? It appears to have the same cutaways as the later bushes do, looking at the parts books. Still a ball bearing can walk if there is too much end float. You set the end float of the crank against that Bush face and the ball bearing won’t walk. The oil film is probably just enough in this case, unlike the roller where it will constantly kiss the thrust washer or the lip of the outer cage. [/quote]




Mr. Gill, the bearing in a crankcase will not come loose and walk if the interference fit is as it should be, nothing to do with the endfloat. If it comes loose, a bush has to be machined into the c.case for a proper interference fit. The oilpump worm gear pull is not that strong. I have seen TS combination bearings needle / ball loose its interference fit in the c.case and walked the other way ( the ballbearing part is what keeps the crank from wandering).



AND, still wondering why my yesterdays answer to Mr Gill is deleted.


Arnstein

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Re: A65 bearings yet again...
Stein Roger #795097 01/07/20 8:51 pm
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Amazon lists the MRJA 1 1/8 bearing for $612.36 + $7.95 for shipping, Motion Industries $276.91, 123Bearing $94.88. CBS $89.95. At least that is somewhat reasonable.
Metric bearings are more readily available than Imperial.
Instead of using the MRJA bearing an NJ306 bearing can be used with a little rework of the cases and crank.
MRJA NJ306
2.8125" 2.8346" (72mm)
1.1250" 1.1811" (30mm)
0.8125" 0.748" (19mm)

Any competent crank shop can build up the drive side and machine shop can bore the case. Add the HJ306 thrust collar and the end float is taken care of. Still have to shim the crank to centre in the cases.
The 0.132" added width of the HJ306 + NJ306 would be taken out of the sprocket spacer.

Re: A65 bearings yet again...
DMadigan #795099 01/07/20 9:08 pm
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If you use an A10 crank the drive side is already 30mm so you just need to open up the case to suit the 72mm O/D. This gives the option of using the NJ306E Norton superblends as well. I wish I had thought of this when I put an A10 crank in my A70. eek


1957 BSA A10 Spitfire
1971 BSA A65 Firebird
1971 BSA A70 Lightning
1975 Norton Commando
1961 Norton 99
Re: A65 bearings yet again...
Servodyne #795104 01/07/20 9:42 pm
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Originally Posted by Servodyne
If you use an A10 crank the drive side is already 30mm so you just need to open up the case to suit the 72mm O/D. This gives the option of using the NJ306E Norton superblends as well. I wish I had thought of this when I put an A10 crank in my A70. eek



I thought you found an A70 crank in the end? The work I am having done on mine is similar to the work you did on yours, although I’m not modifying the cases for the timing side and keeping the standard shim arrangement.


Now let’s all have a beer beerchug

68’ A65 Lightning “clubman”
71’ A65 823 Thunderbolt (undergoing restoration)
67’ D10 sportsman (undergoing restoration)
68’ D14 trials (undergoing transformation)

Re: A65 bearings yet again...
Stein Roger #795108 01/07/20 10:24 pm
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I did, but later found out the drive side had twisted at the end of the splines and had bent the shaft. It must have been one hell of a seize up, probably due to a chain snapping. I was a bit disappointed with the BSA chap that I bought it off as he probably knew it was bent. Luckily it only cost me £100.
The A70 timing side has the standard double thrust washer set up so the cases are not modified.

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1957 BSA A10 Spitfire
1971 BSA A65 Firebird
1971 BSA A70 Lightning
1975 Norton Commando
1961 Norton 99
Re: A65 bearings yet again...
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The NJ306 is the the type i used with a norton crank. (super-nonsense type)
From memory the bearing is a little narrower. On one set of cases we just turned the
bearing OD down with a ceramic tool as it was easier than milling/boring. Both
setups were ok.

The fact that the drive side ball race or in fact any bearing in the drive side
trying to control end-float will be subjected to the thrust of the engine may
may cause the bearing to move when the cases are hot. This is recognised
by nortons and some triumph owners. In the case of the A65, it is prudent
to have an internal shim/spacer to restrict this action to a few thou. Certainly
on the ball race versions as there is a fairly large gap left with no thrust washer.
An external bearing controlling thrust is the overall best way though as it will
also help with stiffening up the crank's drive side flexure.
Why the brit manufacturers didn't go to metric bearings before they did seems
stupid as the metrics were half the cost apart from more available.

Re: A65 bearings yet again...
Servodyne #795111 01/07/20 10:40 pm
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That crank would stand rebuilding and machining these days.
Mind you, you could probably get the 1mm stuck on your A10 crank for
the same cost.

Re: A65 bearings yet again...
NickL #795115 01/07/20 10:51 pm
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Originally Posted by NickL
That crank would stand rebuilding and machining these days.

I may pursue that cheers. There must be someone in the UK that undertakes that type of work as it would be a shame to bin it.


1957 BSA A10 Spitfire
1971 BSA A65 Firebird
1971 BSA A70 Lightning
1975 Norton Commando
1961 Norton 99
Re: A65 bearings yet again...
Stein Roger #795121 01/07/20 11:23 pm
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Is that TP engraved on the DS flywheel about 7 o clock?
Trying to imagine how to straighten it, would be a quite a one off fixture to hold big ends and TS true while the bend was pressed out.


71 Devimead, John Hill, John Holmes A65 750
56 Norbsa 68 Longstroke A65
Cagiva Raptor 650
MZ TS 250
The poster formerly known as Pod
Re: A65 bearings yet again...
Stein Roger #795125 01/07/20 11:53 pm
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Leave it as is, metal spray it all and re-machine all
you would never straighten that out effectively, it would
always want to want to re-form. I was charged quite a
sum once by a machine shop that 'straightened' a crank
of mine, (i didn't ask them to, i just wanted the TS journal
ground round) They showed me it running with a dti and
yes they had it spot on. When i stripped the motor next, i
measured it/ran it in the lathe, sure enough it was the same
few thou or so out that it was originally. I just ran it with buttons
rather than circlips in the pistons and it was fine. It tended to
spit one clip out or dig it into the piston with them. I suppose
some form of heat treatment may have sorted it but it worked
for me with buttons until i got another crank.

Last edited by NickL; 01/08/20 1:01 am.
Re: A65 bearings yet again...
Stein Roger #795132 01/08/20 12:31 am
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I wonder how long the scaffolding pole would need to be to get that straight, in a hypothetical desert island situation with infinite scaffolding available.
Yeah metal spraying, , i always wondered about that, dont hear about so much now, it was quite the thing in the 70s.


71 Devimead, John Hill, John Holmes A65 750
56 Norbsa 68 Longstroke A65
Cagiva Raptor 650
MZ TS 250
The poster formerly known as Pod
Re: A65 bearings yet again...
Stein Roger #795136 01/08/20 12:43 am
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Sounds like a right bugger servodyne. If you ever want to sell it let me know. The belt drive pulls I have fits fine on my A10 crank, but is much tighter on my A65 crank, probably worn by the same cause, it’s hard to tell from the photo how far out of straight the shaft is.


Now let’s all have a beer beerchug

68’ A65 Lightning “clubman”
71’ A65 823 Thunderbolt (undergoing restoration)
67’ D10 sportsman (undergoing restoration)
68’ D14 trials (undergoing transformation)

Re: A65 bearings yet again...
DMadigan #795138 01/08/20 12:53 am
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Originally Posted by DMadigan
Amazon lists the MRJA 1 1/8 bearing for $612.36 + $7.95 for shipping, Motion Industries $276.91, 123Bearing $94.88. CBS $89.95. At least that is somewhat reasonable.
Metric bearings are more readily available than Imperial.
Instead of using the MRJA bearing an NJ306 bearing can be used with a little rework of the cases and crank.
MRJA NJ306
2.8125" 2.8346" (72mm)
1.1250" 1.1811" (30mm)
0.8125" 0.748" (19mm)

Any competent crank shop can build up the drive side and machine shop can bore the case. Add the HJ306 thrust collar and the end float is taken care of. Still have to shim the crank to centre in the cases.
The 0.132" added width of the HJ306 + NJ306 would be taken out of the sprocket spacer.


Hi Dave, would 612$ for a bearing not be for a
Minimum order of 10? I bought mine from SRM, believing I would get the correct C clearance rating SRM RHP MRJA 1 1/8 link


Now let’s all have a beer beerchug

68’ A65 Lightning “clubman”
71’ A65 823 Thunderbolt (undergoing restoration)
67’ D10 sportsman (undergoing restoration)
68’ D14 trials (undergoing transformation)

Re: A65 bearings yet again...
gavin eisler #795139 01/08/20 12:59 am
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Originally Posted by gavin eisler
I wonder how long the scaffolding pole would need to be to get that straight, in a hypothetical desert island situation with infinite scaffolding available.
Yeah metal spraying, , i always wondered about that, dont hear about so much now, it was quite the thing in the 70s.


Metal spray, Spiral weld etc etc. Re-make/build up the primary main shaft and re-machine it.
There's a few firms here that could do it. You'd never bend it back to true again, or if you
did it would tend to re-bend in use. Maybe you could forge it straight but then it would
have to be built up and re-machined anyway.

Re: A65 bearings yet again...
Stein Roger #795140 01/08/20 1:13 am
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Quote.
There must be someone in the UK that undertakes that type of work as it would be a shame to bin it.


If you want a profit on your 100 quid investment, just let me know..................

Re: A65 bearings yet again...
Stein Roger #795142 01/08/20 2:05 am
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No, quantity 1
https://www.amazon.com/RHP-Bearings-NSK-MRJA-1-1/dp/B07DG23R4S
Amazon has some really stupid prices when it comes to bearings. Same when sourcing the 7203-2RS angular bearing for the triple clutch:
https://www.amazon.com/Consolidated-Bearing-ANGULAR-CONTACT-BEARING/dp/B01GPLTEMW ($77.63 + shipping)
Or:
https://www.amazon.com/FAG-Schaeffler-7203-B-2RS-TVP-Angular-Contact/dp/B07DJ56WYR ($201.58 + shipping)
BearingsDirect has them for $9.95

Re: A65 bearings yet again...
Allan G #795153 01/08/20 10:20 am
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Originally Posted by Allan Gill
Sounds like a right bugger servodyne. If you ever want to sell it let me know. The belt drive pulls I have fits fine on my A10 crank, but is much tighter on my A65 crank, probably worn by the same cause, it’s hard to tell from the photo how far out of straight the shaft is.

It's about 13 thou on the alternator journal, but it has other issues which is why I got it for 100 quid. No flywheel, but I was intending to modify a late A65 one with scalloped sides around the big ends and the timing side had been modified to end feed. Unfortunately the LH threads had been removed so that a lock nut could't be fitted and the timing side journal machined down to 1.354". The plain spigot at the end seems to be a separate piece that has been driven into the end of the crank.
I had thought of using a needle roller inner with a 1.5" o/d with oil holes ground through it and retaining the original A70 bush and two thrust washer set up with end feed, as described by Arnstein earlier, but it was not to be.
My A10 crank is working fine so far with over a 1000 miles on it so I'm not in any rush to tear it down.

[Linked Image from i.postimg.cc]

[Linked Image from i.postimg.cc]


1957 BSA A10 Spitfire
1971 BSA A65 Firebird
1971 BSA A70 Lightning
1975 Norton Commando
1961 Norton 99
Re: A65 bearings yet again...
Stein Roger #795160 01/08/20 11:34 am
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I could still make some use out of it, I bought some A10 rods to go with a set of Ed Vs very high compression pistons, I intended to build a long rod A65 motor, I could always make it a 750, if your willing to sell it?


Now let’s all have a beer beerchug

68’ A65 Lightning “clubman”
71’ A65 823 Thunderbolt (undergoing restoration)
67’ D10 sportsman (undergoing restoration)
68’ D14 trials (undergoing transformation)

Re: A65 bearings yet again...
Stein Roger #795170 01/08/20 2:35 pm
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I am not trying to be a smart azz or sound like a dumb azz with the question/comments I am about to pose.....

I have been screwing with these engines for a long time....too long the way I feel today.

In all the years I have screwed around with these engines, I have seen issues with people shimming them too tight, not tight enough, TS bearing clearance wrong, etc. But not once, I have dealt with an engine that had issues with the crank due to oil pump thrust.

I am not saying there is not some factor as driving the oil pump does require a small amount of power. But the minute flow that is available at hopefully 50 PSI on a good day, uses a minute amount of power. Any thrust you get from the oil pump drive is going to require some power when you have a very heavy crank that is walking about inside the engine due to 2 main bearings instead of 3, the effect of firing forces, suction forces, pumping forces through the exhaust, etc.

And lets not forget the primary chain. The triplex chain used on an A65 is heavy and is capable of putting fairly significant side loading on the crank, especially if care is not exercised setting up primary alignment. I have seen far more issues on engines I have had tp get my fingers into due to primary chain misalignment then I have ever seen on the opposite side from oil pump.

I just don't see oil pump thrust being an issue. Lack of end play will play h#ll with the thrust washer or shoulder, but I have not personally seen that from the oil pump alone.


Never underestimate the human ability to elevate stupid to a whole new level!.
Re: A65 bearings yet again...
Allan G #795179 01/08/20 5:48 pm
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Originally Posted by Allan Gill
I could still make some use out of it, I bought some A10 rods to go with a set of Ed Vs very high compression pistons, I intended to build a long rod A65 motor, I could always make it a 750, if your willing to sell it?

Hi Allan. I'm not quite at a position where I want to sell it, but I'll certainly keep you in mind.
Cheers Jim


1957 BSA A10 Spitfire
1971 BSA A65 Firebird
1971 BSA A70 Lightning
1975 Norton Commando
1961 Norton 99
Re: A65 bearings yet again...
Rich B #795184 01/08/20 7:15 pm
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Originally Posted by Rich B


And lets not forget the primary chain. The triplex chain used on an A65 is heavy and is capable of putting fairly significant side loading on the crank, especially if care is not exercised setting up primary alignment. I have seen far more issues on engines I have had tp get my fingers into due to primary chain misalignment then I have ever seen on the opposite side from oil pump.

I just don't see oil pump thrust being an issue. Lack of end play will play h#ll with the thrust washer or shoulder, but I have not personally seen that from the oil pump alone.


Good point about the primary chain alignment. Another factor on the primary drive is flex on the crank and gearbox shafts, the pull on the chain will try to pull the ends of the shafts towards each other pulling the sprockets out of line. The triplex chain is very rigid, any mis alignment puts massive loads on the shafts.
People racing tridents and R3s in the early days suffered crank breakages, a common upgrade was to change the triplex chain to two single chains on the outer sprocket rings, this gave more flexibility when things started squirming around


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Re: A65 bearings yet again...
Rich B #795187 01/08/20 7:51 pm
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Originally Posted by Rich B

I just don't see oil pump thrust being an issue. Lack of end play will play h#ll with the thrust washer or shoulder, but I have not personally seen that from the oil pump alone.

Rich, what kind of catastrophe occurs due to lack of end play? And you mention a "shoulder". Could you clarify where that is?
I'm at that point in my assembly and trying to get it as right as it can be. Crank turns smooths and I'm pretty sure I don't have too much endplay.
Thanks.


1966 BSA Lightning
(2) 1967 Triumph "Choppa"s
1974 Indian ME125
1960 Harley Servi-Car
Re: A65 bearings yet again...
Stein Roger #795198 01/08/20 8:49 pm
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Too little end play will result in damage to the thrust washer (66 on with the correct crank), damage to the shoulder of the timing side main bearing that fits into the case (mostly on 62 - 65 engines), and can cause pinching of the rollers on roller bearing motors. On ball bearing motors, you get short bearing life, but chances are the TS will fail first.

Too much will cause knocking at low RPM. That is the crank banging back & forth inside the cases. IME, too much might cause issues, but not as many issues or as quickly as too little. The thrust washer has a hard life with too much since the crank bounces off of it.

The BSA spec is fine at .0015" - .003". Just take your time and make sure it is right and repeatable.


Never underestimate the human ability to elevate stupid to a whole new level!.
Re: A65 bearings yet again...
Stein Roger #795205 01/08/20 9:29 pm
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I'll be honest and say I don' have much experience with setting end float on A65's and I've only owned one which I bought and rebuilt over the last 10 years or so.

When I bought my 1968 A65 it was a pile of bits so I decided to rebuild it without spending a fortune, this meant I didn't go for and end fed crank, SRM oil pump or belt drive. Instead I was lucky to have a local motorcycle engineer (Tony Hartland) who was very experienced in fitting a new TS bearing, line boring it and assembling the bottom end with the crank cleaned, reground, new big end shells, roller DS bearing and correct shimming and later 1971 --> conrods without the oil hole. I added an SRM OPRV and checked the threads to ensure full engagement & no pressure loss, & added a small amount of thread sealer to ensure no loss.

I carefully rebuilt the alloy oil pump, repaired the gearbox & shimmed it, fitted a new triplex chain and new Sureflex clutch plates. A Norton type oil filter was fitted and the head reconditioned with new valves and guides.

So far after a few thousand miles all seems OK although I did have some problems with wet sumping. I have latterly fitted a later iron oil pump which has helped to resolve this.

My thinking is that the fundamental design is fine as long as an oil filter is fitted, the TS bush is Concentric with the drive side and the oil pump is in good order. The other issue not much discussed is the 4CA points system which reputedly caused a rouge spark on the drive side cylinder, so using a 6CA or EI setup is better in my opinion.

Last edited by gunner; 01/09/20 11:43 am.

1968 A65 Firebird
1967 B44 Shooting Star
1972 Norton Commando
Re: A65 bearings yet again...
Rich B #795209 01/08/20 10:26 pm
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Originally Posted by Rich B
I am not trying to be a smart azz or sound like a dumb azz with the question/comments I am about to pose.....

I have been screwing with these engines for a long time....too long the way I feel today.

In all the years I have screwed around with these engines, I have seen issues with people shimming them too tight, not tight enough, TS bearing clearance wrong, etc. But not once, I have dealt with an engine that had issues with the crank due to oil pump thrust.

I am not saying there is not some factor as driving the oil pump does require a small amount of power. But the minute flow that is available at hopefully 50 PSI on a good day, uses a minute amount of power. Any thrust you get from the oil pump drive is going to require some power when you have a very heavy crank that is walking about inside the engine due to 2 main bearings instead of 3, the effect of firing forces, suction forces, pumping forces through the exhaust, etc.

And lets not forget the primary chain. The triplex chain used on an A65 is heavy and is capable of putting fairly significant side loading on the crank, especially if care is not exercised setting up primary alignment. I have seen far more issues on engines I have had tp get my fingers into due to primary chain misalignment then I have ever seen on the opposite side from oil pump.

I just don't see oil pump thrust being an issue. Lack of end play will play h#ll with the thrust washer or shoulder, but I have not personally seen that from the oil pump alone.



I've probably not been buggerig about with a65's as long as you, i didn't start till 1991 so i accept what you say about the oil pump thrust etc.
I have however seen drive side main ball races that have moved inwards in the cases and could come to no other logical conclusion. It may
be that either poor alignment or insufficient interference fit played a part but i still like to fit a ts thrust washer just in case.
I agree about the primary chain, most of the ones i've worked on they were never lined up properly, people loose the shins etc. Plus they are
nearly always too tight.

Re: A65 bearings yet again...
Stein Roger #795219 01/09/20 2:50 am
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This is the end-feed setup on the A10/65 based thing i'm doing at the moment.
Nice and simple no welding, hollow oil pump stud etc.

https://i.imgur.com/bcVj5D4.jpg
https://i.imgur.com/hkSpFmH.jpg
https://i.imgur.com/ogbTDzI.jpg
https://i.imgur.com/yMc7D4V.jpg
https://i.imgur.com/XXkkFVU.jpg
https://i.imgur.com/wwn2mCO.jpg
https://i.imgur.com/d6uedlS.jpg

Just drill/continue the oil gallery into the lower part of the fixing hole and plug the inner end.

Last edited by NickL; 01/11/20 1:24 am.
Re: A65 bearings yet again...
Stein Roger #795223 01/09/20 8:46 am
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Sirs,

What I'm taking with me from this thread is as follows:

A standard A65 crankshaft system can work well, if set up to the blueprints.
Better still if fitted with an upgraded oil pump and OPRV.
Some prefer a ball bearing on the DS, but load capacity may be an issue on high torque engines.
Modern bearing shells wear better than the original VP white-metal ones. .
The DS timed squirt of oil isn't necessary and might induce a momentary break-down of the oil wedge inside the bearing.
Later rods with the steel cap are stronger than earlier all alloy version. Exotic variants may be even stronger, and some prefer steel.
There is some suspicion that the oil-way drilling in the rod is a stress raiser that can lead to breakage.
A Devimead bearing conversion, or variations of it, is favored by many. Necessitates an end feed conversion too.
An end feed conversion with a plain bearing on a hardened sleeve is possibly a great solution. Arnstein (and others?) has proved that it can work.
Thrust forces must be dealt with unless you use a ball bearing DS, or a compound TS. Arnstein use an outrigger bearing, but not viable for most people.
It's possible to convert to a metric DS roller bearing with thrust capacity on both directions, as on a late T140/TR7 TS. Some machining and/or grinding necessary.

What puzzles me is why so many stick an A10 crank, or even a Norton crank in there. One of the beauties of the A65 design IMHO is it's short stroke and stiff crank.
But that's just me, sorry. grin

SR

Re: A65 bearings yet again...
Stein Roger #795226 01/09/20 11:19 am
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"What puzzles me is why so many stick an A10 crank, or even a Norton crank in there. One of the beauties of the A65 design IMHO is it's short stroke and stiff crank."

if you want more cubic capacity, big bore kits are sometimes unavailable, for long enough they were out of stock at SRM, now theres at least 3 sources, , then a D A10 crank is maybe easier to find.
Having tried both, i prefer the big bore to the long stroke. However , big bore plus long stroke gives 850 ish so theres that to consider. it probably depends on what the builder has lying around at the time.
I built my long stroke motor because I had good 1970 barrels that would overbore a wee bit and found a decent DA10 crank, big bore kits were not available at the time.
As for Norton cranks, never tried one , but the ability to rephase by staggering the big ends is an attractive feature.


71 Devimead, John Hill, John Holmes A65 750
56 Norbsa 68 Longstroke A65
Cagiva Raptor 650
MZ TS 250
The poster formerly known as Pod
Re: A65 bearings yet again...
Stein Roger #795235 01/09/20 2:43 pm
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NickL, You do know you can copy and paste your photos into the forum with imgur?


1966 BSA Lightning
(2) 1967 Triumph "Choppa"s
1974 Indian ME125
1960 Harley Servi-Car
Re: A65 bearings yet again...
Stein Roger #795270 01/09/20 10:57 pm
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Quote
What puzzles me is why so many stick an A10 crank, or even a Norton crank in there. One of the beauties of the A65 design IMHO is it's short stroke and stiff crank.
But that's just me, sorry.


The old quest for power, i'm afraid.
The srm 750 kit made a great engine but on the track it just wasn't fast enough.
The 850/900 kit needed a longer stroke crank, the norton ones were available
for reasonable money, are strong and as Gavin said, they could be offset by
making different flywheels. I had one up at 920cc at one time but the 80x89
motor was the sweetest one i ran with a 76 deg offset.
I wouldn't bother for the road nowadays though. Not that keen anymore.

Re: A65 bearings yet again...
NickL #795292 01/10/20 8:38 am
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Originally Posted by NickL
Quote
What puzzles me is why so many stick an A10 crank, or even a Norton crank in there. One of the beauties of the A65 design IMHO is it's short stroke and stiff crank.
But that's just me, sorry.


The old quest for power, i'm afraid.
The srm 750 kit made a great engine but on the track it just wasn't fast enough.
The 850/900 kit needed a longer stroke crank, the norton ones were available
for reasonable money, are strong and as Gavin said, they could be offset by
making different flywheels. I had one up at 920cc at one time but the 80x89
motor was the sweetest one i ran with a 76 deg offset.
I wouldn't bother for the road nowadays though. Not that keen anymore.

Well I did say it sort of tongue in cheek. I do know the reasons, but a shorter stroke means a stiffer crank and higher revs. I like that.
Norton de-stroked (possibly not even a word?) their incredibly long stroke twin from 89mm to a semi-long 80,4mm to gain stiffness, reliability and ultimately power.
BSA did well with their 650 to cut stroke a full 10mm to 74, which I feel Triumph should have done too when they went to unit construction.
Both the A65 and the T120 started out right but later got bigger valves and ports, too large for their size, so going bigger suited them well.
Going bang quite frequently with it, but what the hell. ohno

But who am I to even talk about this stuff? Here's the truth, I really admire you guys who do or did all this, and envy your skills and determination! beerchug

SR

Re: A65 bearings yet again...
Stein Roger #795338 01/10/20 9:52 pm
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Why is this thread being censored / edited so much ? OK there's clearly been a difference of opinions but surely nothing significant in the scheme of things, if this is the way this forum is heading then I'll be checking out, including my subscription. Come on chaps stop being so sensitive we're discussing old bikes for f##ks sake, there's always someone who knows more than you do, live with it, when its true learn from it.

Re: A65 bearings yet again...
Stein Roger #795348 01/11/20 1:16 am
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We are (or should be) all mature adults on this board so for Chr*sts sake lets live and let live.
No need from what I have seen for any censoring of comments.
We are all old enough and strong enough and ugly enough to give and take a few strong words.
If you are not then you are in the wrong place.
Restricting freedom of expression is what started Germany on the wrong road in 1933.

Re: A65 bearings yet again...
Stein Roger #795350 01/11/20 1:25 am
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Triumph Acclaim!! (Seig Heil)

Re: A65 bearings yet again...
Stein Roger #795353 01/11/20 2:24 am
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You are right Stein about shorter stroke BSA motor having all these advantages you wrote about, but it has also one disadvantage - annoying vibration making you tire quickly somehow more annoying and more difficult to stand than Triumph.
I used very heavy handlebar weights to cure it ( in reality the vibes stayed there but frequency changed more to my liking ) so I felt better and started riding faster.
Result was broken brackets and higher oil consumption.:)
I sold my BSA without those weights and tried it a few times without them, after 200 km I was really tired.
Switched to Trident, which I like very much ( other than annoying oil leaks ).

Re: A65 bearings yet again...
Stein Roger #795368 01/11/20 8:38 am
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Originally Posted by KevRasen
Why is this thread being censored / edited so much ? OK there's clearly been a difference of opinions but surely nothing significant in the scheme of things, if this is the way this forum is heading then I'll be checking out, including my subscription. Come on chaps stop being so sensitive we're discussing old bikes for f##ks sake, there's always someone who knows more than you do, live with it, when its true learn from it.

Well put Kev, and thanks to Tridenman too.
For my sins I haven't been banned yet but this may get me there.
Arnstein is still banned, I just checked his profile. If Gill didn't ban him, Morgan must have. It makes me queasy.
I won't sit still and let it happen without speaking up, as I see no reason, not on this thread anyway. Words and caustic remarks were passed, but nothing worse than most men would take.

Lift the ban, this is no medieval church.

SR

Re: A65 bearings yet again...
Adam M. #795369 01/11/20 9:15 am
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Originally Posted by Adam M.
You are right Stein about shorter stroke BSA motor having all these advantages you wrote about, but it has also one disadvantage - annoying vibration making you tire quickly somehow more annoying and more difficult to stand than Triumph.
I used very heavy handlebar weights to cure it ( in reality the vibes stayed there but frequency changed more to my liking ) so I felt better and started riding faster.
Result was broken brackets and higher oil consumption.:)
I sold my BSA without those weights and tried it a few times without them, after 200 km I was really tired.
Switched to Trident, which I like very much ( other than annoying oil leaks ).

Back on track!
A65 vibrations are well known, and very real! However, I can't see how the stiff crank would create more vibration, the reason must be found elsewhere I believe,
For comparison, when Triumph introduced their T140 based short stroke 650 (76x71.5) everyone who tried it commented on its very smooth low vibration engine.
The TSS got a stiffer crank to cope with the increased power and it reduced vibrations markedly.
But then perceived vibrations depends on the whole system, the frame and attachment points, and maybe some ancillaries.
So who knows. I guess A65 owners will have tried a bunch of different solutions, like altering the balance factor and/or dynamic balancing.
But would they have vibrated less with a longer stroke or a weaker crank?
Interesting stuff.
After I went Triple back in 93 I haven't looked back! :-) I had a BSA A75 which I traded in for a new Daytona 900 which I still have, and 7 years ago I got my stubby fingers on a 72 Trident.
It's the only old Brit Bike i take for longer rides these days, its ride quality and speed belies its age, it's brilliant! And it's oil tight... for now! thumbsup

SR

Re: A65 bearings yet again...
Stein Roger #795382 01/11/20 4:35 pm
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Not to diverge too much from the thread but the source of the vibration is mass centres flailing around offset from their spin axis and other masses translating without equivalent opposite motion. This along with the timing bearing could be addressed by recasting the case for a metric ball bearing on the timing side, metric roller bearing on the drive side and plain bearing support plate between the case halves for the 90 degree offset three bearing crank. The wide centre plain bearing would supply the rods with oil.
Keep the quaint pushrods, roller chain primary and camplate shift direct drive gearbox.

Re: A65 bearings yet again...
Stein Roger #795409 01/11/20 11:07 pm
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If you ride a 750 kitted version of the engine the vibes are reduced considerably.
The tall pistons with their weight high above the pin is a main contributor, even
if you just cut a standard barrel down and run t140 or a70 pistons it reduces the vibes.

Ask anyone with a 750 kitted a65, they'll all say the same, it makes a big difference.

Re: A65 bearings yet again...
DMadigan #795435 01/12/20 10:28 am
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Originally Posted by DMadigan
Not to diverge too much from the thread but the source of the vibration is mass centres flailing around offset from their spin axis and other masses translating without equivalent opposite motion. This along with the timing bearing could be addressed by recasting the case for a metric ball bearing on the timing side, metric roller bearing on the drive side and plain bearing support plate between the case halves for the 90 degree offset three bearing crank. The wide centre plain bearing would supply the rods with oil.
Keep the quaint pushrods, roller chain primary and camplate shift direct drive gearbox.

It's what AJS/Matchless did, minus the 90 degree crank. It did work well too, once they had their crank manufacturing sorted.
But it cost money. Cheaper the Triumph way, so people could afford them.
Not the pinnacle of crankshaft designs, it worked well enough to keep us interested, nearly 5 decades after BSA seized production... clap

SR

Re: A65 bearings yet again...
NickL #795436 01/12/20 12:18 pm
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Originally Posted by NickL
If you ride a 750 kitted version of the engine the vibes are reduced considerably.
The tall pistons with their weight high above the pin is a main contributor, even
if you just cut a standard barrel down and run t140 or a70 pistons it reduces the vibes.

Ask anyone with a 750 kitted a65, they'll all say the same, it makes a big difference.

Very interesting. I rode a Devimead kitted A65 LC once, but decades later I can't recall how it felt. Can't have been too bad then...?
I just learned about the tall A65 pistons. I've seen them often enough but never studied them. The T140 piston is quite a bit shorter overall but also from the wrist pin and up.
The T120 piston is even shorter from the pin, and much lighter than either.
I've often thought that the top heavy piston contributed to the T140 piston noise from cold, and its higher weight must contribute to increased vibrations.

Btw, part of the questions about pistons I had in an earlier post was if the T140 pistons were derived from the A70 project, as the rods were.

SR

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