High oil pressure

[Joe C.]

Re: High oil pressure

Many moons ago, a wise old Indian by the name of Smokey Yunick, told me that 10# oil pressure for each 1,000 rpms was adequate for a race engine. Todays race engines, with the modern lubricants require quite a bit less than to to safely operate.

High pressure and high volume oil pumps in street engines today fall in the catagory of "Snake Oil" remedys.

I agree. The 10 psig/1000RPM rule seems to be the accepted guideline. Pressure will also be very dependent on journal to bearing clearance.

[Domenic T.]

Re: High oil pressure

Were the main journals align honed? If your crank is small journal, then your bearing clearance should be .0021 +\- .0005. If the clearance here is on the small end of the range, your oil pressure will be on the high side.
You should be using Rotella in 10W-30 preferably, if not, then 15W-40.
The oil pump should have nothing to do with idle pressure when at operating temp since the high pressure pump relieves at 65-70psig and the standard pressure spring relieves at 55-60psig.

Actually,
Each different spring has a different low and high pressure, at all temps.

It would be nice that way but there is only a limited space for the spring in the pump.
So a stiff spring restricts the oil from bi-pass also at idle and is at full bi-pass only when fully opened.

DOM

[Dick W.]

Re: High oil pressure

I agree. The 10 psig/1000RPM rule seems to be the accepted guideline. Pressure will also be very dependent on journal to bearing clearance.

Wondering about the Renault F1 engine that turns 19,000 rpms. Rule probably does not hold true in modern racing engines.