1982/1983 crankcase do I need bypass modification

[florent78]

hi guys

I'm rebuilding my engine using a 996 GT3 oil pump.

I've seen the bypass modification as something you can do easily during a rebuild.

looking several videos, I have the big 45° hole
but the small horizontal hole is not located the same side


I'm not sure but it seems Porsche do the modification for late crankcase.


1982/1983 crankcase are supposed to have this factory modification ?


thanks for your help

[KTL]

Your case is already bypassed. They started doing the bypass modification around 1977.

Here's a good thread that gathered all sorts of information about the oiling system

Ultimate Oil Pressure Relief Valve Thread

[florent78]

thanks a lot

so nothing to do on my crankcase to optimise oil cooling and pressure
;-)

[chris_seven]

I wonder why you are fitting a GT3 pump.

I thought that they had a larger pressure section than a 4 bar SC pump and that the Scavenge section was smaller.

I would have thought that if this is correct then the volume of oil mist in the crankcase would be greater and that thus would increase parasitic losses and hence increase the heat to oil.