oil pressure relief spring

[JFairman]

Has anyone shimmed the main oil pressure relief valve spring in a 100,000+ mile 1987 930 or 911 motor to try and raise oil pressure around 5-10 psi or somewhere in that area?
Using 20w50 oil.

If so, how thick a shim, washer, or proper sized nut did you use under the spring?

I used to put a 6mm thread size or 10mm wrench size nut inside the hollowed out oil pressure relief piston before sliding in the spring on old single cam 4 and 6 cylinder BMW engines and it worked great for raising hot oil pressure about 5-7 psi.

Is this considered a bad idea on a 911 motor?

thanks,
Jim

[Eagledriver]

I don't think this will raise your oil pressure since at low pressures the valves are already closed. What will work however, is putting in the cam oil line restrictors. There are many threads on this and it's very easy to do.

-Andy