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.
Paul Bauman wrote:
>
> Gary:
>
> Funny you should mention this. We stopped at an offroad shop that advertised
> K&N filters and while showing the owner the beast, he mentioned that Jeeps
> had the same problem with intake/header thickness. He let me see a manifold
> gasket from chrysler designed to help solve the problem. It was a standard
> flat manifold gasket that came with a set of smaller gaskets that fit on the
> thinner manifold areas to help exqualize things. I was thinking of
> 'sacrificing' a gasket or two to see if this fix would help on my car!
>
> Paul Bauman
> Westminister, CA
> 67 1600
>
> -----Original Message-----
> From: owner-datsun-roadsters@autox.team.net
> [mailto:owner-datsun-roadsters@autox.team.net]On Behalf Of Geegc@aol.com
> Sent: Sunday, February 03, 2002 8:22 AM
> To: datsun-roadsters@autox.team.net
> Subject: Header thickness
>
> The exhaust header I just bought from one of our vendors is slightly thinner
> than the intake manifold. I am wondering if I should grind down the washers
> to create even pressure, or if its not necessary?
>
> Also, any recommendation for manifold gasket sealant? I have some copper hi
> temp spray stuff I was going to use.
--
Marc Sayer
82 280ZXT
71 510 2.5 Trans Am vintage racer
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