............. Two others had broken top rings. Connecting
rod bearings look a little pitted and one had started to "smear". Crank
shaft looks good and should just need a polishing.
Any ideas on why the top piston rings would break? Improper winter
lay-up? Age? Compression was good at 135-150#. >>
If the top rings were broken in three our of four pistons, I'd suspect it had
something to do with the ridges that build up over time at the top of the
cylinder walls.
Perhaps new piston rings or assemblies were installed in the past without
reboring the engine. Honing alone won't totally remove the ridges.
Or perhaps the engine was regularly run and broken in at lower rpms, then
over-revved on the freeway or at an autocross.
How long had the engine sat without firing? Any sign of rust?
Any sign of pre-detonation damage to any of the pistons?
Dick Sanders
Seatte
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