Spot on, John! There are only two scenarios that would have caused this, neither of them good.

well my Porsche 964 was totaled with 80K miles on engine three years ago and no leaks. I used the red loctite 518 shown in my earlier posr

Hmm, I thought we are not supposed to use a silicone based sealant (dirko) for the case, just incase, sorry, pund not intended, may get inside the case and the oil circulation system, right?

I know it will be lessened if one is careful but why take a chance?

Revival of an old thread for dirko by newbie.
 

From what I've read in this forum, the sealing of the case with dirko would allow for any silicone dregs to go to the oil filter via the suction of the oil pump. So it is not a concern and won't get into the oil sprayers (cam and pistons for example). Of course I'm a rookie looking for the easiest solution.

A.) One which yields no leaks and
B.) Easy to apply with a reasonable setup time

Seems like dirko is a good one. Although, I've been impressed with permatex ultra gray too. Dirko has more info herein on how to apply though. I see the 1184 is popular also with accolades from Henry of supertec, seems it only gives me 20 minutes though?

Stick with Loctite 574. Don't reinvent the wheel. Most leaks are caused by clumsy setup and mating of the case halves by inadvertently touching the case parting line and disturbing the sealant.

"seems it only gives me 20 minutes though?"

It's a lot less than that. I used it once on the case seam with no leaks but went back to 574 because it skins too quickly for my liking. It's great for all the other surfaces and gaskets though that can be assembled quickly but I don't like to be rushed when putting the cases together.

Here's the thing. You can ask 4 different experienced professional 911 engine builders and get 4 different answers so pick the one you trust because his solutions more than likely work because he's not going to want to tear down a motor under warranty.
If you don't know who to ask some suggestions are
Henry Schmidt
Catorce
John Walker
Wayne
There are several others also
Stick with whatever they say to the T and that's your best chance for success

Just my opinion
Tony