Engine case sealer?

"Orval Fairbairn" wrote in message
news
In article . com,
"flybynightkarmarepair" wrote:

here is the now superceded Mil-Product spec for this stuff:
http://assist.daps.dla.mil/docimages...74/12/7194.PD9
you want type II, Class C. Manganese cure, faying surface grade
polysulfide.

There is now an SAE spec for this stuff, SAE-AMS-8802

Pro-Seal, beloved (not!) of many RV builders is the same chemistry,
just thicker. You could use the class A stuff, and thin it with
Toluene.

Another poster mentioned what sounds to me like Loctite Gasket
Eliminator, good for up to 200 deg Celsius. That oughta do it, and
it's a whole lot easier to find than the polysulfide.

Volkswagen engine builders use Gascacinch, Yamabond, and some german
goo who's name escapes me at the moment to seal similar faying surfaces.


Do nor use RTV to seal crankcase halves! It allows minute movement and
will cause the mating surfaces to fret.

According to the FAA an A&P in NC put a 6-cylinder Continental back together
with RTV silicone on the studs and under the cylinder flange nuts. The
engine later failed catastrophically in flight killing two in a Bonanza.
One of the cylinders had departed the crankcase, apparently because the nuts
backed off.

"bBob" wrote in message
news:eJnUf.10210$TK2.5516@trnddc07...
After splitting the engine cases, what is recommended for resealing them?

Thanks!

I split a case recently that was nice and dry on the outside. The previous
overhauler had placed two strands of silk thread on the parting flanges, one
strand on the inside of the fastener holes and one strand on the outside.

For the goo use Permatex Aviation Formagasket. I don't know if Hylomar is
legal or not but it's great stuff too. Thin it a little with acetone.