Re:Gasket sealant, need everyone opinion.

[Chris.Prael@xxxxxxxxxxx (Chris Prael)]

> Date: Fri, 28 Aug 1998 17:48:35 -0400
> From: Bruce Murray <bmurray@domain.elided>
> Subject: Re:Gasket sealant, need everyone opinion.
> 
> >
> >I was told to used Permatex Ultra Gray on 164 thermostat housing=20
> >and CAM cover as gasket sealant.  It is a very good stuff,=20
> >stay pliable and never hardened.  Funny it is a little bit=20
> >hard to find Ultra Gray while there are Ultra Blue, Ultra Black...
> >on every auto store.  I finally found one.
> >
> >As for 164 intake duct gasket glue, Ultra gray is not sticky enough.
> >I use Permatex high tack gasket sealant.  It's hard to apply but=20
> >easy to clean with alcohol.=20
> >
> 
> Well since Karl asks for everyone's opinion here's mine:-
> 
> YOU SHOULD ABSOLUTELY NOT USE SILICON GASKET SEALER IN AN ENGINE WHERE
> IT IS IN CONTACT WITH THE OIL SYSTEM.
> The little pieces that are sqeezed out of the joint will set up and may
> fall off inside the engine. They can then fall into the oil system and
> may cause blockages.
> 
> ALFA, I seem to remember, issued a service bulletin which said that the
> engine warranty would be voided if silicon sealant were used.
> 
> The car manufacturers may provide gaskets which have a silicone applied
> in a carefully controlled quantity so that none can get into the engine.
> 
> Silicon Gasket Sealer is OK for the water passages I suppose but even
> there small bits could clog the radiator tubes.

OK, now you get another one.  

I raced Alfas for 5 years.  I started out using Permatex products to
seal the engine.  In the second and third years, I had a series of
failures, all caused by spun main bearings.  I made a number of changes
to correct the problem.  

One change in engine building which corresponded with the arrival of
reliability was to switch to using only silicon sealer on the whole
engine.  So, not only did using silicon sealer cause NO problems, it
appears to have contributed to stopping the problems.

Silicon sealer must be used CORRECTLY.  If you slob enough on the
gasquet, a lot of silicon is extruded and certainly can cause problems
as detailed by Bruce.  But, WITH CORRECT USE, NO PROBLEMS OCCUR, AND
NO OTHER SEALER IS HALF AS RELIABLE.

That's been my experience with the stuff.

Chris Prael

------------------------------