[TR] Engineer Question again!

Randall TR3driver at ca.rr.com
Sun Apr 20 17:56:05 MDT 2014

> So, I happen to have a liner and piston that came out of an 
> old engine.  Would there be some odd harmonic imbalance if I 
> were to use three pistons of one type and a fourth of a 
> different type?  ...In other words, do I need to yank all 
> four pistons and liners and repace them with a matched set?

Are the piston weights roughly the same?  If not, you'll get some vibration, but maybe not a great deal.  I once bought a TR3 where
someone had replaced only one piston (not sure about the liner) with a noticeably lighter aftermarket piston.  I drove it a few
thousand miles in the TR3, then moved it into a TR3A without ever noticing that it vibrated any more than the old 3A engine.  Didn't
discover the mis-matched pistons until after it blew a head gasket and I removed the liners to clean out the water jacket.

Assuming the bore is the same of course.  Might notice more vibration if the bores didn't match; but again I've heard of it being


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