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A-Series Oil Pressure [Opinions Please]

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dklawson

dklawson

Yoda
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The subject of oil pressure frequently comes up on every A-series forum, including here. The discussions are full of variables and there's never a consensus. I've seen some people say that oil pressure as low as 10 psi is OK while others insist the pressure needs to stay near 50 psi (all the time).

A friend of mine has been following such a thread on the email Spritelist. I'd like to have a series of comments from people on this forum just to see if there is a consensus for the following conditions. What is a normal (or typical) range for A-series oil pressure given the following:
1) recent rebuild w/new oil pump and bearings
2) hot engine (say 185 degrees)
3) idle speed close to 900 RPM

I'm not really going anywhere with this, I just would like to see what long-term owners of A-series cars have seen and consider acceptable.

I have no basis for knowing what is correct but I'll start by saying that I would like my oil pressure to stay at or above 25 psi in a hot A-series idling between 800-1000 RPM.
 
I would think that 20 would be more appropiate on most of these engines. But higher is better.
 
Mine stays at about 25-30 with 20w50 at 190 degrees.
It is usually 20-25 with 10w40 at 190 degrees.
 
But... I've never checked the accuracy of my gauge.
 
When I rebuilt my engine, I consulted with APT on this subject since it was around 45lbs.

They had told me anything above 20 was good and above 40 was to high, since it would be splashing too much oil around and cause a power loss.

I have shimmed mine out to 30lbs for now.

Patrick
 
Hmmm, maybe my 20-40, idle and 3K RPM is just fine with 20 50 oil and 180 degrees. Guess I will not mess with it at present.
 
Doug, on a fresh rebuild, I typically see about 35PSI at a hot, ~900 RPM idle. And about 60~75 PSI at speed.
This is with correct bearing clearances, new pump and relief valve.
If I've done everything right, I'll see pretty much the same numbers 20,000 miles later.
Jeff
 
Good to hear Jeff. As I was reading this thread I was thinking mine is pushing a bit too much. Fresh rebuild, and I mean fresh, 60 at start. Hot around 40. Jumps up to about a consistant 65 @ 2000 rpm.
 
There is a very good web site hosted by BCF, called Spridget Tech. In there are a few manuals and handbooks.

I see that the 948 and 1098 idling (minimum) pressure is listed at 10 to 25 psi. While the 1275 lists idle at 20 psi, but doesn't use the word minimum.
 
At speed Jeff, I wish. Miss Agatha has been all the way up to 30 MPH. Our speed limit here in the community is 20. Yea I know but she is not finished so not insured or titled yet and these are all private roads.
 
Mine is a 1275 that runs 50PSI @1000 RPM and 70PSI @4000 RPM. I have no intentions of adjusting anything being that I have been driving it for two years with these readings. I might add that is very close to 50000 miles that I have put on it in those two years. Also for about the last eighteen months I have averaged 43 to 45 miles per gallon running the SU HS2 Carbs. Keep in mind that this is 99% interstate driving, not stop and go. I run Castrol 20W50 Synthetic Blend with 8OZ of Lucas oil stabilizer. I run the same oil in the rib case tranny with 4oz of the lucas oil stabilizer. I run 75-140 Valvaline Synthetic in the rear end. I am running 175/70R13's on the front and 175/80R13's on the rear. The rear Diff is a 390 ratio. With the calibration done on the Speedometer for tire size correction it turns 4300 RPM at 75 MPH.
 
Great info. Thanks for that.
 
Middleagecrazy, is your 50psi @ 1000RPM for a hot engine or cold?
 
Man, if that's 50 thou miles just going to work, I would definately lokk for another job /bcforum/images/%%GRAEMLIN_URL%%/cryin.gif Better yet, why not just retire? /bcforum/images/%%GRAEMLIN_URL%%/yesnod.gif
 
It is indeed! Pretty cool to hear that you actually put that many miles in a LBC--I mean, you are driving her all the time!! Good for you. /bcforum/images/%%GRAEMLIN_URL%%/smile.gif
 
Hay, nice talk. These little cars were built to be driven and driven and driven. Just don't forget the maintance that goes with it.
 
Listen to Jack. Maintenace is the key to the life of these little cars. I change the oil in mine every three thousand miles and change the tranny oil yearly as well as the rear end. After this many miles the only modification that I am considering would be the five speed conversion. But that will not happen until I need a clutch replacement. I would not consider going to another vehicle. I accually like it better than the wifes 2003 Jaguar.

Anthony
 
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