Allen Nugent wrote:
>
> Tom,
>
> At 18:52 20/02/98 -0800, you wrote:
>
> >I agree fully with Dean. NO SEALANT ON A HEAD GASKET...... If you want
> >to use something, one old timers trick is to spray a coat of aluminum
> >paint on both sides of the gasket ...
>
> I always thought sealant was essential. I've done a Mazda, a Toyota, and 2
> Triumph heads. The last one was with copper gasket spray (the gasket failed
> in 8 months, but I think that was because I re-torqued it hot instead of
> cold; didn't study the manual carefully enough).
>
> I suppose it depends on the head. The Dolomite (TR7, Stag) engine has those
> angled studs, which must mean uneven stress on either side, and these make
> it especially sensitive to head-fitting technique.
>
> One of the guys in TSOA(NSW) removed and refitted his Sprint head at the
> racetrack, using the old gasket (!) with copper gasket spray. He continued
> racing, and I think he even won one.
>
> Any comments?
>
> Allen Nugent
> Graduate School of Biomedical Engineering
> University of New South Wales
> Sydney 2052 Australia
I would think the copper spray (I forgot to mention this earlier)
would do the same as the aluminum. It provides metal particles to bond
with the metal on either side. If the theory is right, probably
anything with a metal content will work. If you noticed the copper
spray probably did not leave hard to remove residue either ( I know the
aluminum paint doesn't)
The gasket at the track may well have survived this way & may have had
additional help. For high compression race engines, many mechanics
"open up" the ring on the gasket that lays around the cylinder & add a
piece of .020 or .030" wire, then lay the ring back down to provide
additional sealing for the added pressures.
Makes sense to me. I just don't know if anyone has ever documented
help from using the aluminum or copper paint in a scientific manner; or
if its just a bunch of people like me perpetuating the idea. I'm sure
the advertising on the can of copper cote will tell us its virtues are
proven. Maybe they are.
My feelings have always been (in any mechanical matter), make it as
clean as you can, as accurate as you can in every aspect (ie torquing
sequence, rate etc. ... clean flat machined surfaces, clean threads,
properly matched peices etc) & you will have no problem.
Hope this helps.
Tom Strange, Classic Autosports Ltd., Appleton, Wi., 920-733-5013
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