The XPEG head on my TF 1500 has been shaved too many times. With the
static timing set at TDC, it is on the edge of pinging even when premium
fuel is used. By interpolating the stage tuning data, the compression ratio
is around 9.6. Readings on a compression gauge are between 175 and 180 psi
on all cylinders. The engine was recently overhauled. Octane boosters seem
to help, but they are expensive and a hassle to fiddle with.
To reduce the compression ratio to 9.3, my calculations indicate that a
.085" gasket " (compressed) should be used. The Gasket Works in California
makes copper gaskets that are this desired thickness. I am told, however,
that copper gaskets tend to leak unless special precautions are taken. Is
this true? What are the special precautions?
There are other options like shaved pistons and increasing combustion
chamber volume. Are these other choices advisable?
Thanks,
Ben Prince
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