Britbike forum Forums British Motorcycle specific Brands Bsa bulletin board A65 Timing Side Reamer

I think the a65 original material was VP23 a type of leaded bronze i believe.

I am turning my own bushing out of SAE 660 ( also known as C93200) which is a lead/bronze alloy.
You can buy it on line here, minimum of 12 inches of thick walled tubing. Should last me what's left
of a lifetime. I can't remember exactly what outside/inside diameters I chose, but can go measure
the lump in the garage if anyone cares.

The VP23 was a steel outer with an inner steel backed bush with VP10 leaded bronze material, a sales dept way of differentiation. This had a lower lead level than the big end VP2 and so did not need the overlay plate to protect the lead from acid leeching. VP10 bushes are very popular as a small end bush material.

To replicate the VP10 you need the following bronze.

Pb 10% Sn 10% Cu 80%

VP2 has 23% Pb, 1.5% Sn and 75.5% Cu

As a fully Bronze bush you lose the strength of the steel backing, so it will not have the same properties especially likely to have a lower fatigue strength. In a main bearing this may not matter but there is also greater risk of distortion from loading.

But to the point made by Ignoramus, you don't want to be stuffing (technical term) a reamer through that, to try to re-size it or change the axis of orientation. The only bush you should do that to is a solid bronze bushing and even then, you should be using a boring head to machine the bearing surface. A reamer to adjust the sizing by a very small amount, if you think it needs it. Better to have the crank journal ground by a few thou to fit the bush.

Clearly, the factory thought you should just whack out the old bushing and beat in the new with a lump hammer, after waving a big hairdryer at the cases.

PS the timing side main in my cases doesn't look like that photo. Mine has the 'ears' on it that locate it in the case casting.

Kibblewhite offers crank bushings with no steel liner...

https://shop.kpmivalvetrain.com/c/british_bsa_a65-1971-1972_bushing-crankshaft

I think those are superior to the brit bike bits bush in the link that NickL posted :

Because you can machine them to fit. Buy an undersize and bore/ream it as required.

But what ticks me off is the 'blurb' on the Britishbikebits web page :
>BEWARE OF PATTERN BRONZE/BRASS BUSHES!!

Why is that? No reason offered. Just 'scaremarketing'. But here is the catch-22 :

>Procedure as per workshop manual, Old bush to be pressed out and securing pegs removed.
>New bush to be pressed in and line reamed to suit crank, then pegged to stop it turning in the housing
>Please note that this is only suitable for standard size

You have to 'line ream' to suit the crank, but the bush is in standard size only. So, unless your crank has magically
expanded in diameter, you can't ream a standard size bush to fit a used crank. Even if you could, the reamer would
rip out the wafer thin bearing material. Unless you have a brand new, unused crank, this bush is useless to you.
This is the kind of supplier BS that just irritates the heck out of me.

"Oh, you followed our instructions and your big end seized and the con rod poked a hole in the crankcase? Yes sir,
we stand right behind our product. We will refund you the price of the bushing."

[/rantoff]

Just looking at that burton bike bits bush, it’s a split bush like the swing arm bushes on my oif. Interestingly for those the manual does state do not resize the bush (swingarm) however when they come sized that the inner section won’t fit when the bush has been fitted then what can you do. So I placed an expanding reamer through mine. Worked it out in small increments and kept cleaning and trying the centre piece till it was spot on.

The defining factor though between these two systems is the bushes are less than an inch apart on the swing arm. Not the case on the crank casing and the crank setup is subject to more wear and other issues than the swingarm.

this may have been answered, but frak deihl goes to work every day. ‭(843) 520-0481‬ excellent wrk.
rick

Exactly the same material I make my crank bushings from

Kyle/Malcolm - That is a bit ambiguous.
You mean items like this ?

I bet you a dollar to a doughnut, that is made out of SAE 660.

Steve.

Pretty sure its Phosphor Bronze

The steel outer does make the bearing stronger, an all bronze bush is easier to make though.
They are probably stating the warning as so many bushes over the years were turned out by
blokes and made of any yellowish material they had.
Some people reckon that having the shaft hard chromed and ground is a better way to go, if
that method is followed then re-lining the steel outer is great. Beware of the overall fit though,
as the case holes can be hammered out if the main has been bad for a while. I prefer the steel
versions but they are harder to find now and you are stuck with a fixed od so you can only use
them if the cases are good. Lining them with 660 is fine as an alternative. It's more work though.
As for super fine alignment, if you bolt and unbolt the cases a few times it'll change anyway.
Same as if you heat and cool them. Do the best you can, they aren't space ships.

PB1 may not be such a good idea due to it being very hard. But that's only my opinion.

https://mgaguru.com/mgtech/engine/pdf/vandervell_mg.pdf

PB is too hard IMHO
I always prefer LG 2 or 85-5-5-5
Which al almost as strong and has the added avantage of the lead lubricating the bush should the oil pressure fail.

LG2 (leaded gun metal bronze) is excellent material for this application , as i mentioned who knows how many posts ago on this thread its what i used when i redid the bush on my A10 after a catastrophic failure (threw a rod)

It machines really well and you can raise a really good finish on it straight off the tool when you use zero or negative rake single point cutters. Also it cuts true to size

What i do find quite amusing is how some of the experts who go on about line reaming etc claim you must use a really sharp multi flute reamer ! This is exactly the wrong tooling to use on bronze alloys , Sharp rake tools will dig in and cut oversize , but once again what would i know All the dedicated brass/bronze reamers or drills , particularly spade drills ,I ever used in the manufacturing industry (plumbing hardware etc ) were all ground with a negative rake leading edge

I've just been back through the thread, and can't find where you referenced the material you used. It's good to have confirmation that LG2 is an appropriate material for this application.
You noted that you made a replacement insert for the original steel shell.
Would LG2 be a suitable material for a one-piece bush to use in a flogged-out timing side crankcase, or would it be better to make an oversize steel housing? Alternatively, would sleeving the case be suitable?

DANG you are right i did mention making a new inner for a good original steel sheel and did think i had said i used LG2 , i though so anyhow . I must have mentioned it in some other similar thread.

Fact remains that its what i DID use LG2 ( lead gun metal) ... the bottom end has come out really well using this material i made it with minimal clearance but obviously enough as it has not shown a hint of nipping up and on first oil change after maybee 100 miles there were zero sparklies in the oil ...

but to your question: i recon it would be perfect to make a solid replacement bush out of ....it is actually a fair bit harder that the standard phosphor bronze the after market bush makers CLAIM they use , but who knows what they actually do use ?

Thing is when you buy material from a trade only engineering supply merchant and specify a grade you can be sure that is what you will get!

without knowing just how "flogged out" the case is its a bit hard (and maybe misleading to offer to much of an opinion . but i would say i would avoid bushing the case it would end up being a very thin bush(more like a shim) and possibly not as rigid as a single case/bearing interface , effectively you would be bushing a bush

if you recon its only say 5 or so thou i would just make a slightly oversize LG2 solid bush and be prepared to spend a lot of time on some careful hand scrapping

Trevor (despite our history of disagreements) is a very knowledgeable metallurgist and if he says LG2 is the best material i would go with that ...the fact myself and Trevor are on the same page says it all IMO .........all i am realy saying is that is what i used and it has worked very well (probably around 5k miles by now)

Trevor can give you the technical reasons its good for teh application , all i can say is i used it and it was great

I think it was Trev from Newcastle ( TrevinOZ ) does LG2 sleeves shrunk back into the original steel outer which should work even better but is too much fiddleing around for me to attempt .
Thought he may have chimed in but perhaps not as he is a pre-unit twin man so may have skipped this thread.
The only other thig to mention is LG2 comes in two forms,
'Continiously cast solid & extruded tube.
For this application the extrude is by far the better material to use due to finer grain size & beter grain orientation .

LG2 is a universal bearing material.
We used to make at least 1 pour ( approx 6 ton ) a week as SFI .
the only place I would use something different is for valve guides because you want the guide to be harder than the valve stem in which case a phos bronze would be the go, and a leaded phos bronze even better .

And yes Ignoramus is correct about machining,
high speeds with negative / neutral rake
Hand scrapes beautifully if you have some old worn out files that need to be repurposed & the skills to use them.

And that should be WAS a metallurgist, been 40 years since I wore a dust coat .
I find myself needing to whip out the ASM handbooks a bit more often these days.
But yes it is good to be in agreement for a change.

As for the warnings about solid bushes, they should all be fine.
The big problem is most copper based bearing materials look very much the same so it is difficult to tell exactly what materail they are made from visually.
I got some bushes for the M20's box decades ago that were actully cast then machined ( badly ) to ( almost ) size.
A cast bush is highly likely to crack radially and then of course crumble away and I have a feeling that the warnings may have come from that happening.
These things are what you would expect to find unbranded for sale on evil pay or ammo-zone very cheap .
As a rule a good supplier will be able to tell you exctly what alloy the bushes they are selling are made from.
If not go some where else, and by exactly I mean LG 1, or 2 or 3 ( etc ) PB 1, 2 ( same thing ) .
For the USA it should be a 3 or 4 number material code.
If they just say "bronze " then walk away .

Nicely written Trev.


There are a lot of good one piece bushes on the market.. heck theres a lot of people putting many miles on them. Just depends who did the machining and who made the bush.

I think this is where companies like SRM (in the UK and others around the world) do good. I don't like everything they do, but I do like most things and wouldn't considering going anywhere else for the "same part" The bush I have recently had fitted is one of their PB ones.

Steel backed split piston pin bushes are used in diesel engines.

How would one of those work for a T/S bush on a bsa? They come un-sized with about .015" for machining.

This is of course assuming there is one of the right size.

YEP Trevor im sure you are right about the technicalities of the material, i just machine it ! , i had to learn it as part of my degree but like Maths 3 i took great delight in forgetting all of it !

Only thing i would say about your authoritive post is that you said:


" is correct about machining,
high speeds with negative / neutral rake"

depends what you mean HIGH SPEEDS ? on a bush id of that size i would not go above say 250-300 rpm reaming ( i used spiral reamers ) on a production auto ( although technically not right i would flood it with Ilocut 437 NOT soluble! , feed something like 4 thou per rev , probably just doing a one off on a center lathe i would drop that down even further to say 150-200 using HAND FEED you have a good feel if it starts hogging in and less chance of it heating up

I would do the rest of the turning. Boring at 800-1000 rpm same feeds
I loved doing production work like these on CUSTOMER SUPPLIED material , my line was simple, "there are so many bronzes i dont want the risk of incorrect material and its very expensive so YOU supply"

IN reality i just wanted the swarf hahaha .......had one customer ask for the swarf back so i told him sure but i charge $150 for a machine clean down after brass/bronze (it must be cleaned thoroughly or you get too many slinters next set up! , you still want it ? he didnt and just laughed and said oh well it was worth a try ..i further explained that I dumped at least $20 of ilocut with the swarf ...sure i spin it but you never get all the cutting oil back


PS I love the idea of "sweating " the liner in i thought about that but didt have any silphos but it would be the definitive job...i do pity the next comedian who didnt realize it had been sweated in and tried to get it out .......maybe a note with an engraver on the open end of the bush ?

I have a one piece bush in my A65 , fitted it back in the 80s, - 10 i think so far so good but time will tell..........i have an idea it was silicon bronze, it kind of felt and looked greasy.....I showed it to a top tradesman at some dump i was working at and he told me it was silicon bronze he said excellent material for your bike YOUNG fella DANG young fella ( i was so broke in those days i got the bush in approval and told the seller i wanted it looked at by a top turner and if he said the material was no good i could take it back)

One thing for sure is i bet the cheapskates who spin up this aftermarket stuff wont be using that material! , to them if its yellow its bronze

These would be VP10 as a Vandervell made Bush or SY if a Glacier bush. Chemically the same, Vandervell cast on steel, Glacier sintered onto steel. Difficulty is finding the right sized bush, Perkins or Cummins would be a good start. The same bronze is used by most steel backed bronze bush makers. Just stay clear of modern car engines which are lead free and the bronze suffers.

Glacier Industrial Bearings do SY bushes in imperial sizes.

So here's the story behind my question. BTW, thanks to everyone for the very useful comments.

I don't like the solid T/S bushes commonly available these days so I dug around online and found a John Deere steel backed pin bush.

It is too long, but the OD is a nice press fit in the original A10 steel outer. The unfinished ID is about .015" under standard T/S journal diameter.

There is some fiddly work to get it all pinned and drilled but from what I am hearing, it sounds like it should work pretty well. The factory oil hole is a little big though.

you shouldnt need to line ream if you use the proper genuine bush,reaming with a reamer is crap if you must do it use a milling machine