Oil pressure....It is always 30 psi hot, at idle in gear and never drops below that figure. The oil jets in the block open around 15 psi, IIRC.

My Dad's 617.952 drops down to around 10-15 psi at hot idle. Since the 617 oil pump is chain driven, as opposed to gear driven, there isn't a wear issue using higher oil pressure. When I rebuilt the engine, I used a new MBZ oil pump and added a custom made, .060" stainless steel shim under the pressure regulator spring. We will be doing the same thing on Dad's 617.952.

I did this on EVERY 617 I worked on at the dealership and have many still in service with good results...Robert