BritBike Forum logo
BritBike Sponsor BritBike Sponsor BritBike Sponsor
BritBike Sponsor

BritBike Sponsor

BritBike Sponsor
BritBike Sponsor BritBike Sponsor BritBike Sponsor
JWood Auction JRC Engineering dealers JWood Auction
Home | Sponsors, Newsletter | Regalia | Calendar | Bike Project | BritBike Museum | Spiders Cartoons, "OLD" BritBike Forum | DVD- Manuals & Parts books | BritBike Stickers & Decals
Upgrade to: Premium Membership | Premium Life Membership | Vendor Membership | Site Sponsor Membership
Photo posting tutorial

Member Spotlight
lincolntbird
lincolntbird
Caveside, Tasmania, Australia
Posts: 21
Joined: July 2013
Show All Member Profiles 
Shout Box
Search eBay for motorcycle parts in following countries
Australia, Canada, France, Holland, Italy, United Kingdom, USA
Random Gallery photo
Who's Online Now
192 registered members (68 royalstar tony), 1,661 guests, and 517 spiders.
Key: Admin, Global Mod, Mod
Newest Members
David Stothard, iansouthoz, Lightning Sim, Simon.Holyfield, Bushcreature
10036 Registered Users
Top Posters(30 Days)
Lannis 148
kommando 113
Stuart 61
Popular Topics(Views)
478,672 mail-order LSR
Forum Statistics
Forums33
Topics65,743
Posts635,554
Members10,036
Most Online3,995
Feb 13th, 2017
Like BritBike.com on Facebook

Previous Thread
Next Thread
Print Thread
Rate Thread
Page 1 of 2 1 2
A65T Oil Pressure - Update #5526
10/24/05 5:04 pm
10/24/05 5:04 pm
Joined: Feb 2006
Posts: 125
CA
BSA Mark Offline OP
BritBike Forum member
BSA Mark  Offline OP
BritBike Forum member
Joined: Feb 2006
Posts: 125
CA
Hi

Here's an update on the trial of the low oil pressure. (BSA 1971 A65T oil in frame).

After removing the oil strainers / filter (sump and crank) only to find small amounts of none magnetic metal (bearing material) not very much in total perhaps 1/8th teaspoon.

Upon removing the sump filter my missing dip stick suddenly appeared! I have no idea how it got passed the clip at the oil fill point but I now have an original!

Removing the oil pressure relief valve (50 PSI) to find a lot of goo which looked like old gasket material. The 7PSI warning indicator came out too but looked clean.

When putting it all back together I installed an oil pressure gauge (kit from British Only) keeping the 7PSI indicator as part of the pressure circuit (a little copper pipe work was involved here but it looks OK, I'll replace it with a piece of stainless in the future). Filled her up with 20W-50W and went for a cruise.

Initial the oil pressure was 50 PSI, but slowly the pressure reduced to about 16PSI after riding for about 30 minutes (60MPH). At Idle the pressure approached 8PSI but the warning indicator did not come on. Perhaps if I would of kept going the pressure would of continued to drop.

I'll let two weeks pass (100 mile of biking) keeping an eye on the pressure. I'll check the filters and look for bearing material. (Which I hope not to see).

Mark


1971 BSA Thunderbolt
Support Your #1 BritBike Forum!
Membership Type! Free
Member
Premium
Member
Premium Life
Member
Vendor
Member
Site
Sponsor
Recognition No Premium Member Premium Life member (5 years) Vendor Member Site Sponsor Membership
Post commercial threads No No No Yes Yes
Custom title No Yes Yes Yes Yes
Upload avatar & photos No Yes Yes Yes Yes
Link avatar & photos Yes Yes Yes Yes Yes
Private Message Storage: 10 100 100 100 100
Length of signatures 255 600 600 600 600
Removes this very advert island between post 1&2 No Yes Yes Yes Yes
Price Free $12.90/year $105.00 No End
$55.00/5 years
$210.00/year
($17.50/month)
Email
Click on button >>
  Premium Member Premium Life member Vendor Member Site Sponsor Membership
Re: A65T Oil Pressure - Update #5527
10/25/05 12:48 am
10/25/05 12:48 am
Joined: Jul 2001
Posts: 12,327
Central Virginia
Lannis Online content

Life member
Lannis  Online Content

Life member
Joined: Jul 2001
Posts: 12,327
Central Virginia
Mark -

Your pressure sounds exactly like mine, and like everyone else that carefully monitors pressure on a well-built A65. For better or worse, for richer or poorer, that's what you get; I'm sure it'll be fine....

Lannis


I'm like super lazy today. It's like normal lazy, but I'm wearing a cape.
Re: A65T Oil Pressure - Update #5528
10/25/05 2:00 am
10/25/05 2:00 am
Joined: Oct 2001
Posts: 237
Monclova
S
sloppyoil Online content
BritBike Forum member
sloppyoil  Online Content
BritBike Forum member
S
Joined: Oct 2001
Posts: 237
Monclova
16lbs of oil pressure is not enough. When the old beezer seizes it'll high side you. Bush and rod brgs, crank serviced. If you don't one of those rides will ruin your day.

Re: A65T Oil Pressure - Update #5529
10/25/05 2:06 am
10/25/05 2:06 am
Joined: Feb 2006
Posts: 125
CA
BSA Mark Offline OP
BritBike Forum member
BSA Mark  Offline OP
BritBike Forum member
Joined: Feb 2006
Posts: 125
CA
Hi Lannis,

I say a little prayer each time I see the pressure heading towards 7PSI when I'm away from home. However as I only use the bike for weekend adventures with my 12 year old daughter, I'm not to worried.

Still the old BSA gets everyones attention (and the occasional Harley rider will give her a second glance).

Each day I walk past the bike I smile looking forward to the weekend.

I hope you're keeping a eye on the fairy dust that magically appears in the oil filters. (Aka bearing material).

Mark


1971 BSA Thunderbolt
Re: A65T Oil Pressure - Update #5530
10/25/05 10:32 am
10/25/05 10:32 am
Joined: Aug 2001
Posts: 4,988
Stone Creek OH USA
R
Rich B Online happy

BritBike Forum member
Rich B  Online Happy

BritBike Forum member
R
Joined: Aug 2001
Posts: 4,988
Stone Creek OH USA
If your finding bearing material on a regular basis in your sump, you have an engine that is about to die. Your low oil pressure is directly related to loss of bearing material. Less material means less resistance to flow, hence low pressure. Reduced pressure leads to more material loss, with even lower pressure. It is a vicious cycle. It needs to be corrected before you have a damaged crank, damaged rods, or even a rod through the case.


Life is too short to drink cheap, bad beer.
Re: A65T Oil Pressure - Update #5531
10/25/05 11:39 am
10/25/05 11:39 am
Joined: Aug 2001
Posts: 315
florida
C
cycarmark Offline
BritBike Forum member
cycarmark  Offline
BritBike Forum member
C
Joined: Aug 2001
Posts: 315
florida
What is the part number for the British Only gauge system? I'm interested in checking the pressure on my A65T.

Re: A65T Oil Pressure - Update #5532
10/25/05 12:06 pm
10/25/05 12:06 pm
Joined: May 2005
Posts: 3,776
ohio
shel Online content
BritBike Forum member
shel  Online Content
BritBike Forum member
Joined: May 2005
Posts: 3,776
ohio


When given the choice between two evils I picked the one I haven't tried before
Re: A65T Oil Pressure - Update #5533
10/25/05 12:31 pm
10/25/05 12:31 pm
Joined: Aug 2001
Posts: 315
florida
C
cycarmark Offline
BritBike Forum member
cycarmark  Offline
BritBike Forum member
C
Joined: Aug 2001
Posts: 315
florida
Mine is a '70 model, non oif, but the engine should be the same, thanks!

Re: A65T Oil Pressure - Update #5534
10/25/05 12:49 pm
10/25/05 12:49 pm
Joined: May 2005
Posts: 3,776
ohio
shel Online content
BritBike Forum member
shel  Online Content
BritBike Forum member
Joined: May 2005
Posts: 3,776
ohio
they list them for other models too, i wasn't sure what year your bike was


When given the choice between two evils I picked the one I haven't tried before
Re: A65T Oil Pressure - Update #5535
10/28/05 9:37 pm
10/28/05 9:37 pm
Joined: Feb 2006
Posts: 125
CA
BSA Mark Offline OP
BritBike Forum member
BSA Mark  Offline OP
BritBike Forum member
Joined: Feb 2006
Posts: 125
CA
Been away for a few days.

During riding I'll see as low as 20PSI however at idle it creeps lower down to 10PSI.

My plan is to break the engine down over christmas to take a look at the infamous end bearings.

Next weekend (to busy this week) I'll take the sump off and inspect the oil for bearing material. (Hopefully there isn't any).

Mark


1971 BSA Thunderbolt
Re: A65T Oil Pressure - Update #5536
11/03/05 7:14 pm
11/03/05 7:14 pm
Joined: Jun 2003
Posts: 85
west virginia
bluzdoctor Offline
BritBike Forum member
bluzdoctor  Offline
BritBike Forum member
Joined: Jun 2003
Posts: 85
west virginia
Hi All:

This is about the pressure I am getting; no metal in the sump, though. I think Lannis is correct, this is the norm for a original A65 motor (without the roller-baring conversion). All the local BSA mechanics I have talked with say this is normal and you have to adjust to the seemingly low pressure or, if you want to race, then do the conversion.

bluz


1971 BSA A65T
1984 BMW R100RS
2008 Triumph Tiger
1964 Bultaco Matador
Re: A65T Oil Pressure - Update #5537
11/04/05 6:07 pm
11/04/05 6:07 pm
Joined: Oct 2001
Posts: 237
Monclova
S
sloppyoil Online content
BritBike Forum member
sloppyoil  Online Content
BritBike Forum member
S
Joined: Oct 2001
Posts: 237
Monclova
You guys are tempting fate. A proper A65 should maintain a steady 50 to 55 lbs of oil pressure at 2500 rpms and above. If it is that low it is worn out. Side bush, big ends, sludgetrap cleaned, service oil pump. If thats all the pressure you have and believe it will be ok, or the lot of A65's are like this I have a bridge to sell. Spend the money to make the bottom end up to snuff first. You will be happier in the long run. And always remember the slang for BSA Bastard siezed again. They said that for a reason. be safe.

Re: A65T Oil Pressure - Update #5538
11/05/05 1:29 am
11/05/05 1:29 am
Joined: Jul 2001
Posts: 12,327
Central Virginia
Lannis Online content

Life member
Lannis  Online Content

Life member
Joined: Jul 2001
Posts: 12,327
Central Virginia
Sloppyoil -

I've got too many tens of thousands of miles on too many A65s to go along with the "it has to have 50 PSI or it's worn out".

Matter of fact, you're the ONLY guy I've ever heard say that. It might be an interesting data point but it's probably not "The Last Word" on A65 BSAs..... I'd rather ride mine than chase some theoretical oil-pressure figure anyway.

Lannis (already got a back yard full of bridges...!)


I'm like super lazy today. It's like normal lazy, but I'm wearing a cape.
Re: A65T Oil Pressure - Update #5539
11/05/05 1:53 am
11/05/05 1:53 am
Joined: Feb 2004
Posts: 1,956
Flint,Mich
norbsa48503 Offline
BritBike Forum member
norbsa48503  Offline
BritBike Forum member
Joined: Feb 2004
Posts: 1,956
Flint,Mich
I think what you would like to see is 10lbs per 1000 RPM. So 7 lbs at idle is not bad on a hot motor at idle. Remember that the rotating crank full of oil maintains it's own back pressure at the rods. norbsa


norbsa
1960 TR6
1963 Super Rocket
1965 650 Star
1966 441
1968 Thunderbolt
1969 Twinkle 250
1972 Fastback
1974 Roadster
1970 S.S
Way too many BSA's not named
http://decentcycles.com
Re: A65T Oil Pressure - Update #5540
11/05/05 3:16 pm
11/05/05 3:16 pm
Joined: May 2002
Posts: 687
Winston-Salem N.C.
D
D.W.R. Offline
BritBike Forum member
D.W.R.  Offline
BritBike Forum member
D
Joined: May 2002
Posts: 687
Winston-Salem N.C.
Why is it that everyone seems to miss the point that if you have a 50 lb. pressure relief valve, you see 50 lbs? My Rocket 3 has a 90 lb. valve, and cold pressure is 90 lbs. Norbsa and Lannis are both correct on this.
Don


71 Rocket 3
72 B50 MX
66-71 A 65 Bitsa
96 Trident 900
Re: A65T Oil Pressure - Update #5541
11/05/05 3:27 pm
11/05/05 3:27 pm
Joined: Jul 2001
Posts: 12,327
Central Virginia
Lannis Online content

Life member
Lannis  Online Content

Life member
Joined: Jul 2001
Posts: 12,327
Central Virginia
Don -

The relief valve spring gives the max, as you say. Mine shows 55 PSI (spring pressure) for the first 10 minutes of running, then drops off and follows the RPMS pretty closely as it heats up. Many perfectly healthy A65s show much less than 50 PSI hot at cruising, and less than 10 PSI at hot idle....Your Rocket's pressure makes my Firebird jealous, but anything over 15 or 20 PSI is just squirting back to the scavenge sump anyhow...or at least that's what I tell myself..!

Lannis


I'm like super lazy today. It's like normal lazy, but I'm wearing a cape.
Re: A65T Oil Pressure - Update #5542
11/06/05 2:48 am
11/06/05 2:48 am
Joined: Aug 2001
Posts: 315
florida
C
cycarmark Offline
BritBike Forum member
cycarmark  Offline
BritBike Forum member
C
Joined: Aug 2001
Posts: 315
florida
I put an oil pressure gauge on my 1970 A65T and here are the results: At startup, 55psi at idle and at 35 mph. As the engine warmed up, the pressure dropped to 16 psi at 50 mph and around 7 or 8 at idle. It remained there after a 30 min or so ride. I run straight 50 weight oil, and checked the sump strainer and it was clean. The engine sounds and runs fine, any reason for concern?

Thanks

Re: A65T Oil Pressure - Update #5543
11/06/05 4:03 am
11/06/05 4:03 am
Joined: Apr 2005
Posts: 2,337
Bega NSW Australia
Mark Parker Offline
BritBike Forum member
Mark Parker  Offline
BritBike Forum member
Joined: Apr 2005
Posts: 2,337
Bega NSW Australia
I run an oil cooler and pressure gauge all the time and have a roller conversion, and no doubt a slightly boosted relief valve, and usual hot pressure is 70-75psi at over 3,000rpm. If its particularly hot weather (over 105deg) that can be less but never below 45-50. Because of the end feed I'd ride it with 20psi but only to get home and fix it, (I have worked on a Norton that we put a gauge on that had 5-7psi at rpm, it had been like that probably for some time with no ill effects, but the end feed ensures oil gets into the crank, with a std BSA feed through the bush I wouldn't be very confident of that.)
When the oil seal on the end feed fails or starts to it has a pressure drop naturally in proportion to the degree of failing, but what is interesting is that that oil going past it into the t/case then into the c/case causes a wet sump effect and lots of smoking esp in r/h cyl, and have noticed my brothers BSA with the std bush has a greater tendency to smoke on that cyl, maybe because of oil distribution in the c/case out the sides of the bush.


mark
Re: A65T Oil Pressure - Update #5544
11/06/05 1:42 pm
11/06/05 1:42 pm
Joined: Aug 2001
Posts: 3,871
Cape Carteret, NC
M
Mr Mike Offline
BritBike Forum member
Mr Mike  Offline
BritBike Forum member
M
Joined: Aug 2001
Posts: 3,871
Cape Carteret, NC
I agree that the BSA for a variety of reasons (bushing, oil pump, pressure relief setup) runs with less than optimal oil pressure. I think that these A65 motors, probably run about 25k, maybe 30k before the bores are worn out and the rods and bush are well worn. That apppears to be the nature of the beast. Mine is just like the rest of the a65's... 55 cold but drops significantly when hot. I think that you could easily double that engine mileage with a motor that ran with 50-55psi hot at 3500 rpms and 20-25psi at hot idle. I am going to try to achieve that on the next motor I do with a lot of attention on the pump, pressure relief and the bush.....the easy way (more $$)is the conversion, then you only have to worry about the rods getting 55psi.

Mr Mike

Re: A65T Oil Pressure - Update #5545
11/07/05 2:18 am
11/07/05 2:18 am
Joined: Oct 2001
Posts: 237
Monclova
S
sloppyoil Online content
BritBike Forum member
sloppyoil  Online Content
BritBike Forum member
S
Joined: Oct 2001
Posts: 237
Monclova
I don't want to appear like a smart *** but you guys are taking a chance. If anyone of you a65 riders on this thread have a BSA service manual look up the proper oil pressure. It is 50 lbs at 3000-3500 rpm hot. I have this kind of oil pressure with a stock engine in good running condition with 20-50 castrol. I learned my lesson the hard way in the 70's. You won't find any false neutrals when it siezes. Good luck.

Re: A65T Oil Pressure - Update #5546
11/07/05 2:20 am
11/07/05 2:20 am
Joined: Oct 2001
Posts: 237
Monclova
S
sloppyoil Online content
BritBike Forum member
sloppyoil  Online Content
BritBike Forum member
S
Joined: Oct 2001
Posts: 237
Monclova
Hey man I just do not want to see anyone get hurt because of misleading information. Most of all if someone has their kids on the bike for a ride.

Re: A65T Oil Pressure - Update #5547
11/07/05 3:21 am
11/07/05 3:21 am
Joined: Aug 2001
Posts: 3,871
Cape Carteret, NC
M
Mr Mike Offline
BritBike Forum member
Mr Mike  Offline
BritBike Forum member
M
Joined: Aug 2001
Posts: 3,871
Cape Carteret, NC
Sloppyoil,
I don't think anyone will disagree with you that 50 psi (hot)at 3500 is ideal but most BSA twins with a bushing motor, chintzy oil pump and suspect pressure reliefs have trouble maintaining that kind of pressure...mine included. If my motor gets another rebuild some day, I will be going to a lot of effort to get things fixed so it will hold 50 psi. Also (and this is only my personal opinion) these motors which make 50 HP and are fun to hotrod have no center main bearing. Not uncommon for two cylinder motors. Crankshaft probably flexes and a rigid bushing wears quite fast under flexing conditions. This inturn bleeds off oil pressure and things can go poorly after that. An adequately sized ball bearing on the timing side would probably help this situation and it can get by on splash oiling, leaving the rods to have all the pressure to themselves.

Mr Mike

Re: A65T Oil Pressure - Update #5548
11/09/05 7:17 am
11/09/05 7:17 am
Joined: Apr 2005
Posts: 2,337
Bega NSW Australia
Mark Parker Offline
BritBike Forum member
Mark Parker  Offline
BritBike Forum member
Joined: Apr 2005
Posts: 2,337
Bega NSW Australia
Some of the low oil pressures mentioned I would be trying to fix, especially if the bikes are still running with a bush. there is no reason not to be running with at least 50psi hot. The first thing I would do is remove the pressure relief valve and stretch the spring a bit and see what that does,(force a small screwdriver shaft down through the coils, one side then the other so it stays straight)the springs can loose tention, and if it means you are running 80psi it won't hurt, mine goes past 100psi in winter before it warms up, with 20-50, you can adjust it for what you want, if you stretch it too far squash it back down in a vice (without destroying it). In summer use thicker oil, I use 25-60. A65's also benifit from having an oil cooler, Marric's description sounds like the oil is thinning alot from heat. If low pressure persists without a good reason check the pump bolts esp the ones holding it together they can loosen and allow excess oil out the side of the pump, most seep a little even when tight, just make sure they are tight. I have found that to have 50psi hot means you will have maybe 70psi cold, I to once had a trident, it ran about 90psi hot and well over 100 cold without me messing with the std pressure relief valve.


mark
Re: A65T Oil Pressure - Update #5549
11/10/05 2:20 pm
11/10/05 2:20 pm
Joined: Jul 2005
Posts: 1,919
new jersey usa
J
John RGS Offline
BritBike Forum member
John RGS  Offline
BritBike Forum member
J
Joined: Jul 2005
Posts: 1,919
new jersey usa
Here is the fix. A.convert to roller bearing. B. run for a couple of weeks and moniter oil pressure.C. use BSA tool 3257<black electrical tape> and cover oil pressure gauge and see shrink about OCD.


,_o
_ -\_<,
(*)/'(*)

NOPGS #2
Re: A65T Oil Pressure - Update #5550
11/16/05 1:02 am
11/16/05 1:02 am
Joined: Nov 2005
Posts: 11
South Coast NSW Australis
G
Green Offline
BritBike Forum
Green  Offline
BritBike Forum
G
Joined: Nov 2005
Posts: 11
South Coast NSW Australis
I am in the market for a 68 - 70 A65 and have been watching this thread intently.

I am interested to know the secret of sloppyoil's success. What year motor and how many miles since bottom end rebuild and any other detail you can provide? Who built the motor as it sounds like good hot oil pressures are definately achievable (40psi hot 3500rpm) with standard engine?

Maybe just an oil cooler would fix alot of these issues?

thanks Green

Page 1 of 2 1 2

Moderated by  Allan Gill, Jon W. Whitley 


Home | Sponsors | Newsletter | Regalia | Calendar | Bike Project | BritBike Museum | Spiders Cartoons | "OLD" BritBike Forum | DVD- Manuals & Parts books | BritBike Stickers & Decals
Upgrade to: Premium Membership | Premium Life Membership | Vendor Membership | Site Sponsor Membership
Powered by UBB.threads™ PHP Forum Software 7.6.1.1