[billjam]

Originally Posted by Walt Fricke

Bill

Have you confirmed that the engine oil thermostat from the pre-964 cars will fit and work in your later case? If I have this right, for your case Porsche dispensed with this thermostat so the pressurized oil always flowed through the filter. Since you are putting a filter on (BJ: I think you mean "cooler"), it would benefit from the protection the thermostat gives it against overpressure when the oil is cold.

In pictures, the 964 appears to have just a cover plate with some sensors over that hole. When running an RSR system (filter, not cooler, for earlier cases) you have to install a special plug into the thermostat hole to be sure the oil always flows through the filter, and that the cold oil short cut hole is always blocked. Does the 964 case have this short cut passage permanently blocked/not cast/drilled?

Walt

Thanks for the heads up on this. It seems that retrofitting a cooler isn't difficult - others here have done it - so I am sure I can make it work.
I don't have access to the crankcase at present to check the oil passages, however I recall noting that the casting looked the same as earlier engines but some of the passageways for the cooler and the thermostat weren't drilled through.
When I do this mod, I will document exactly what needs to be changed and post here.