question about the case casting...
 

I have my engine apart and I was cleaning and cleaning and noticed an interesting attribute of my SC's motor. I was a little nervous about what appeared to be a flaw in the casting. I didn't get a snapshot of it but I found a few pics on the forums of some open cases and added an arrow.

whats going on here?
http://forums.pelicanparts.com/uploa...1408021576.jpg

Don't panic. My 86 930 looked the same.

http://forums.pelicanparts.com/uploa...1408022839.jpg

Internally there is no problem, but Porsche issued a technical bulletin to seal the outside of the case around the sleeve. I used a little JB Weld.
http://forums.pelicanparts.com/uploa...1408028425.jpg

It's a little hard to tell from the pics, but are these imperfections exposing the internal oil pipe to the open crankcase? I'd find such an imperfection hard to believe since it would seem to cause loss of oil pressure, not just a little seepage.

Its just a possible drip but I clean, wire brush, and JBWeld inside of oil cooler area and out side under #6.
Bruce

Scott,

You are correct that this thin area of the casting exposes a section of the "J" pipe that goes from the pressure side of the oil pump to the engine case, up to the internal t-stat housing. There's no oil pressure loss because the pipe is continuous and well-sealed at the oil pump end.

The seepage is caused is from splash oiling inside the case (at that thin area) that then finds its way outside the case at the oil cooler recess as shown in the TSB.