In a message dated Mon, 4 Feb 2002 3:22:24 PM Eastern Standard Time,
JLBrooksNC writes:
> I guess I missed the start of the thread...
> What kinds of problems do you get when the manifold is too thick or too thin?
> UNDEQUAL PRESSURE ON THE INTAKE AND EXHAUST SIDES FROM THE NUTS WHEN
>TIGHTENING IT UP.
>
> And a follow up question... What is the torque specs on the manifold and carb
>to the head? GOOD QUESTION, PERHAPS TOM WALTERS KNOWS.
>
> And the third... do I use a sealent around the exhaust/carb gasket? I've
>heard red RTV... ALSO GOOD QUESTION, SOME DON'T USE ANYTHING.
>
> TIA
> JB
> 1968 2L
>
> In a message dated Sun, 3 Feb 2002 5:42:42 PM Eastern Standard Time, Marc
>Sayer <marc@gracieland.org> writes:
>
> > No! (Well okay, it might work for a few folks, for a while, but it is a bad
> > "solution") You do not want to arbitrarily mess with the compressibility and
> > compressed thickness of gaskets. In fact this is generally one of the worst
> > cheap fixes for this problem. Gasket design is based on science and you
>can't
> > really just mess with the gaskets like this most of the time. The proper
> > solution for a bunch of reasons (including a tendency to warp the flange)
>is to
> > buy headers made with the correct thickness flange. Any other solution
> > (including gaskets, tabs welded onto the header flange, and stepped washers)
> > will only lead to problems. You *might* be able to address a problem where
>the
> > intake manifold flange was thinner with one of these approaches, as the
>intake
> > manifold does not tend to warp, but with a header this is a major waste of
>time.
> > Yes a car maker could perhaps design a stepped or two-part gasket that would
> > work, maybe. But an individual does not have the resources to do the R&D for
> > this, *and* the issue of header flange warpage is still unresolved with this
> > approach. In order of preference the solutions to this problem are;
> >
> > 1-get a header with the right thickness flange
> > 2-use stepped washers (because this way at least the header flange is the
>same
> > thickness throughout)
> > 3-weld tabs onto the flange (welding on the tabs will warp the flange and
>the
> > flange must be surfaced *after* welding, plus the varied effective
>thickness of
> > the flange will cause warpage problems)
> > 4-use stepped gaskets (NOT recommended)
> >
> > Spray on Copper Coat or just plain silver hi-temp paint (the aluminum
>pigment in
> > the paint acts as a gasket dressing) work well.
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