I have Loctite 574 for the block halves.
Åke

 

I've never seen Porsche say this.

Perhaps Jeff can ask Katie and see what "Classic" has to say.

 

Just stating a fact:
Porsche uses Drei Bond between the case halves on some of the later generation 911 engines.

 

There's no allowed tolerance for sealant between the engine block and the cradle.
Metal to metal is the goal, since 928 engines are align bored without any sealant present.
Any thickness of sealant is going to increase the main bearing clearance.
[I've seen layers of Loctite 574, applied by rookies as thick as 010"....Kevin in Atlanta had this issue (and had a leaking cradle) and I taught him the "tricks".]

Therefore,, any sealant applied is there to simply seal any surface irregularities.

......I've always found it very interesting that even on factory built engines, there is always a very thin layer of Loctite 574 that needs to be removed from the surfaces.

This is not desirable.

Presumably, this is caused by the quickness that the Loctite 574 cures, when very thin....not all excess can escape before a very thin layer of Loctite cures.

I use a "non-factory" method of tightening the cradle to squeeze out as much Loctite as possible. Disassembly shows that this certainly reduces the thickness of the hardened layer of Loctite 574, even better than the factory method.

However, I can also imagine that a better sealant may have been developed, over 50 years later from the beginning of using Loctite 574.

Yeah, I know....radical concept!

 

The Drei Bond 1209 packaging provides two additional data points that the manufacturer's web site and their data sheet do not: silicone type and tack free curing time. I've updated the table, but the the time window to edit the original post has expired. So, here's the updated table:

 

So, after all that research, which one of those is best for our use?

 

Someone should do this same exercise with Motor Oil