Oil pressure poll

[Richard Saunders]

The water temp poll post was a good one. Always interesting to learn about others' experiences. So how about something similar on oil pressure at a normal A road cruising speed rather than tick over. Personally upper 40s.

[milothedog]

Totally agree Richard, very interesting. and it would appear that the general consensus is that most cars on average operate quite happily between just over a 1/4 and under 1/2 on a standard gauge set up. mine falls in to this category but spends most of the time at the lower end.

The same can be said for your poll on Oil Pressure, most cars sitting at around 40-50 psi normal driving, as does mine. Over 55psi if pushing on a bit and 20-25psi at idle all when hot.

Ian

[StephenP]

The question is,
What is 'Road cruising speed' ?
30 ? 50? 75 ?

Steve

[Richard Saunders]

Let's say 50mph.

[chopperman]

How accurate are the oil pressure guages? In the aviation industry, we had to calibrate them every year or so.
Keith

[ChasR]

On the two gauges tried in the car, 45PSI at 50MPH.

[jleyton]

Let's say 50mph.

Ah yes, but in an auto that's about 2500 rpm and in a MOD it's closer to 2000 - with a possible consequent effect on oil pressure

Just my two penn 'orth

Cheers

Julian

[V Mad]

I suggest 2000 rpm is a good point to compare?

I was disappointed that the poll stopped at 50+, yet went all the way down to 10-20. I cant imagine anyone is running at 10-20 at cruising speed unless they are doing an expensive test!

I am really interested in anyone running at 60-65; 65-70; 70plus. The new County pumps seem to put out pressures well above 50, and I would like to know if anyone had reliably run at high pressure (60 or more) for a long time? Does a very high pessure put a strain on the timing chains, pump drive shaft or jackshaft?

I was not comfortable at that high pressure so I have modififed my spring aiming for 50-55. I seem to be getting 45 at the moment which is a bit too low for me, but I havent checked if the gauge is accurate.

[NickA]

Is there a "Don't know as I've not got an oil pressure gauge fitted but I've a clock that's right twice a day" option?

[Bob Heritage]

I think the original spec for the Stag is about 40psi. for a Holbourne Eaton pump. I will have a look through the literature unless somebody beats me to it. A lot of you are running too high with the aftermarket pumps.

[Andrew S]

I bought a brand new Smiths oil gauge years ago and it always read just over 50 and was 55 at 2000 revs and picked up really quickly. Never dropped below 30 when really hot. I buggered the gauge when changing the bulb set up and have got another one that has been calibrated and it now reads just under 50 at 2000 revs and drops to 25 -30 when hot. I feel it should be higher or I want it higher and was considering a new pump

[wilf]

I gained at least 5psi when i put a new gauge in recently. My view is that if the engine is happy and keeping its internal bits where they belonged, it has enough pressure.

One way to make yourself happier is to do what I did - find a gauge with 60psi max reading rather than the more common 100psi. That way it always indicates above half way, even close to the maximum when cold, psychologically much better for me.

[richardthestag]

when hot mine is
30psi at idle,
45psi at 1000rpm
50psi at anything over 3000rpm

even when cold it doesn't go over 55psi but then I also don't do much more that 2000rpm when it is cold

[Bob Heritage]

I think the original spec for the Stag is about 40psi. for a Holbourne Eaton pump. I will have a look through the literature unless somebody beats me to it. A lot of you are running too high with the aftermarket pumps.

Had a look through some literature and can't find anything, even in the BL Manual, but I'm sure I read it somewhere many moons ago. But found some useful info in the Technical Reprints, Tony Hart says : 45-50 hot at 3000rpm and on the racing engine it is limited to 45max with 260bhp at 7500rpm.
On page 24 (18) There is a report saying that the valve opens at 30-35psi and tops out at 40 looking at the graph. Some good reading to be had there.

[tjk]

Hi

Re oil pressure see text below from a Triumph service training notes booklet

OIL PUMP
An external oil pump secured to the crankcase by four bolts and washers
tightened to 16-20 lb. ft. (2'2-2'8 kg. m.). The oil pump is driven by the idler
shaft via the distributor.
An '0' ring provides a seal between the pump and block.
The oil pressure with the engine at correct running temperature should be
55-55 Ib'/sq. in (3'5-3'8 k9./sq. em.).
An oil pressure relief valve is fitted integral with the oil pump base plate and
consists of:
A. Relief valve
B. Spring
C. Spring location plug and '0' ring
D. Split pin securing relief valve to assembly.


TJK