I tend towards the over-cautious particularly when it is a pain in the a**
to re-do a piece of work. Since I have a bad back, bending over the carbs
and stuff to repeatedly pull the whole mess to get the dang passages to seal
pushes my caution into the "only do it once" range.
I also discovered that the thickness of the flanges on my Solex manifold
were about .050 thinner than those on the SU manifold that I had run
previously. This caused the four big thick washers to cock slightly sideways
and not apply full clamping force to the intake manifold, resulting in a
persistent (and significant) leak when I built my last engine. I finally
figured that out my THIRD TIME of removing the stinkin' manifold!
Since I was running a tube header, it was a simple matter to grind down the
matching tabs to equalize the height and solve the problem. But it just
about drove me crazy!
I know some people don't use any gasket sealer, and if that works for them,
good enough, but I still do. I use a VERY THIN layer of Copper-Kote on any
thin paper gaskets that see oil (tensioner gaskets, for example). These are
usually used between two carefully machined surfaces that are unlikely to
have major scars. I use a VERY THIN layer of Hylomar on any thicker gaskets,
those that see water (water pump, thermostat housing) or non-machined
surfaces (timing cover, tensioner cover, fuel pump). I use a thin layer of
spray Copper-Kote on the head gasket.
In no case do I put the stuff on like cake frosting, like I have seen on too
many engines. The engine is supposed to be BOLTED together, not GLUED.
Proper mating of the surface will really squeeze any gasket sealer down to a
very thin layer. Any excess will squeeze out both inside and outside the
engine. All you need is a very thin, but very consistent, layer with no
gaps.
Now, ya gotta understand, I learned this from experience. Early on (a few
decades back), I put the intake manifold on once with a nice thick coat of
non-hardening Permatex. When I tore the engine down later, I found Permatex
"streamers" going down the intake ports like melted wax! Sheesh!
Fortunately, an old toothbrush and some solvent took it out, but I started
to learn my lesson.
Gordon Glasgow
Renton, WA
www.gordon-glasgow.org
> -----Original Message-----
> From: owner-datsun-roadsters@autox.team.net
> [mailto:owner-datsun-roadsters@autox.team.net]On Behalf Of
> RacerY@comcast.net
> Sent: Sunday, January 29, 2006 11:51 AM
> To: Roadster List
> Subject: RE: Rebuilt Engine Ready to leak - Help
>
>
> If you've done it RIGHT and gotten both the manifold and the
> ports surfaced,
> then I'd say that Gordon was being overcautious.
>
> But NO-ONE machines those, so I'm in full agreement- the surfaces
> are seldom perfect, and the worst thing that can happen is a
> little seep that will erode the surfaces... so I seal it, too.
>
> But I don't usually use sealant on gaskets... well, except maybe
> on the thermostat tower on a 1600...
>
> Toby
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