On 4/8/2013 12:32 PM, PrecisionmachinisT wrote:
....

With a solid valve train, when the poppet valve wears, it starts
seating deeper and deeper up into the head...eventually, thermal growth
of the pushrods causes there to be no valve lash whatsoever, result
being a loss of compression at the affected cylinder(s) but only when
the engine is fully warmed.

--continued running under this condition will rapidly cause both the
valve and seat to burn.

Easy rudimentary check is warm it up then remove valve cover and make
sure you can at least spin the pushrods by hand when the piston are
at TDC of ignition stroke.

This subthread headed where I was going to suggest...check compression.

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