The big-end bearings in my TR6 sound worn. There's a rumble at low-revs and
the characteristic higher frequency `knocking' at low revs when I put
my foot down (not the high-frequency pre-ignition knock).
However I replaced the bearings approximately 8,000 miles ago.
The crank must have been reground in the past as the bearings I replaced were
20 thousandths undersize. I used similarly sized bearings.
For a while everything seemed tight, but now this is obviously not the
case.
Has anyone on the list any suggestions to what I should do?
I don't want to take the engine out of the car. Everything else
is functioning satisfactorily. I'd like the engine to do another
30,000 miles before I give it a full rebuild. I'm happy to replace the
bearings with 20 thou undersize again. However big-end bearings last
longer than 8000 miles and so my conclusion is that the crank is more
than 20 thou undersize. Can I use 30 thou undersize bearings without a
crankshaft regrind.
Has anyone on the list any advice?
Many thanks.
Giles Nelson.
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