I5 NA exhaust manifold gaskets -- which way?
Ado Sigal
a.sigal at bluewin.ch
Sat Dec 16 00:06:42 EST 2006
Jan Pinkowish wrote:
>Stock I5 NA 2.2L exhaust manifold-to-cylinder head gaskets have metal on one side.
>I am somewhat but not totally embarrassed to ask the following:
>
>Which way does the metal face -- towards the cylinder head or towards the manifold flange?
>
>What's the operating logic for a one-metal-sided gasket?
>
>Jan Pinkowish
>
>
>
>
First to say that you've got the old gasket design. In Europe for last
couple of years the new design for all models, has no metal plate at
all, only the inner metal ring, and this gasket has more than a
millimetre bigger aperture all round. Since the old ones couldn't be
found, I blueprinted the head and manifolds again on my Urq.
The very first design had metal plates on both sides and had smallest
aperture. The logic then was to place the smooth metal side towards the
head, so the hard inner ring doesn't dig into the head. Same logic was
used for the design you have with one metal side. Most but not all VAG
engines I came across had this logic applied. Temperature wise its same
thing really, and some builders argue better seal when turning the metal
plate towards manifold, and ring towards the head. The new design
evidently proves both to be right approaches, although the engine
builders at Heini Mader Racing that was visited for manifold welding,
pointed that on turbo engines, because of greater expansion rates, one
wants the gasket to be as smooth, therefore the ring on iron, and plate
on alu. Rare alu castings also as he said, always use same method. So,
officially as it seem the choice is yours, and if you want a set from
here, you'll have no choice at all.
Regards,
Ado
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