Hi Folks, enjoying Rick's notes on head gaskets. Skimming our Ardun
heads .003/.005 every year is not an option for obvious reasons, Zora
only approved .020 total for clean-up and the less we do that the
better.
Fortunately we are not facing 150/200 horse per cylinder either, if we
ever get up to 50 we have a stormin' engine with "that sound".
Just for curiosity, I looked up the clamping load of just one 7/16 ARP
stud with molygrease and 60 foot lbs torque. It would be right around
14,000 lbs (ARP catalog). Since the Ardun uses 20 studs, the total
clamping force twixt head and Flathead block would be 280,000 lbs. I
imagine this would not be perfectly uniformly distributed, but rather
more around the stud points, since both the head and block would give
way a little under these forces, away from the stud points. So there is
a lot of strength left in our antique Flathead blocks, with good old
Ford iron in 'em.
If we use a flat dead-soft copper gasket this is the kind of pressure we
have to seal the water holes, assuming no low spots on head or block.
In practice, water leaks are not unknown, and the "Bars Leak" type of
sealer is the first resort.
I gather the NHRA Top Fuelers all use the flat copper gasket, probably
no sealer needed or wanted, under hydraulicing or bad detonation
conditions the gasket blows sideways, they have no water to contend
with, and they like the feature of adjusting compression ratio with
various gasket thicknesses. I imagine they use no wire o-ring, but
probably have 1/2 or 9/16 studs on those monsters. Maybe someone knows.
I like Rick's moniker or nickname for a famous auto maker, "Fraud", it
reminds me of a quotation from Anthony Trollope, Victorian English
novelist whose main subject was the life of the aristocracy, which went
something like "Lady X had only a vague idea of the distinction between
commerce and fraud."
Cheers from Ardun Bill in the Great Dismal Swamp, Chesapeake, VA, where
Spring has sprung.
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