> Did you use new rockers and/or rocker shaft? If so, the rocker shaft
> could be seizing. This could cool enough to let every thing free up
> enough to run good until it gets hot again. The same thing could occur
> if the valve to stem clearance is too tight. (Did you have a valve job
> done with new guides?)
Bronze expands more than iron at a given temperature and new bronze
valve guides reamed to iron valve guide specs can seize a valve when
the engine gets warm. Had that happen once on a freshly rebuilt MGB
engine.
TeriAnn
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