What should the oil pressure guage read during normal operation, and raceing?
Matt

 

Oil pressure is a strange animal.

Pressure depends on a number of variables:

Oil Temp

Bearing clearances

Oil weight

Oil type (synthetic or dino) straight or multi-weight

Type of oil pump used

Engine rpms, etc.

As a rule of thumb, you'll want 20 psi at hot idle and 10 psi per thousand rpm the engine turns.

HTC told me that some of the Winston Cup guys run .001 bearing clearances and ZERO weight oil to reduce pumping losses.

Hope this helps.

Jake

 

So when my guage is reading 40 at normal in town speeds, is that good or bad?

 

i've seen differant psi in differant referance manuals. some say 10 psi for each 1000rpm, other say 25-55. 40 isn't bad at all for driving. psi @ idle is always lowest reading you'll see, i'd start to worry if it dropped to 20. lot of people will get 60 or more on start up.

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ICON Motorsports
1st & 3rd
MM Black Diamond 538 F&AM

 

40 around town is fine. Pressure shouldn't drop below 20 at idle, but some passenger cars run as little as 10 from the factory with no problems.

10 per thousand rpms essentially means 60 psi at 6000; 70 psi at 7000. Most of the performance crate engines you see for sale in the mags run a bit more, around 70 or a bit higher.

If you go too far in max pressure, though, you will blow the oil filter, unless you are running the kind with the higher rated burst pressure. Another weak point is the rubber gasket on the filter (filter to block) which will blow out with excessively high pressures.

Use to run straight 50w in the 1/4 mile drag cars I built engines for and YOU'D BETTER NOT REV THE ENGINE COLD!

Jake



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1986 Corvette Coupe, 415 CID, Edelbrock 6073s, ZZ9, TPIS Long Tube Headers and DynoMax Super Turbos (HATE 'em)