-----Original Message-----
From: bighealey3k@aim.com
To: racarbon@verizon.net; healeys@autox.team.net
Sent: Sun, Jan 3, 2010 1:28 pm
Subject: Re: [Healeys] Strange Engine Situation
Sounds like the piston rings were replaced without removing the ridge at the
top of the cylinders causing the compression rings to break at top dead center
and in time damage the upper ring lands. I rebuilt a neighbors '62 tri-carb
engine back in approx. 1989 that had a serious rod knock after having some
engine work done by a "hack". I dropped the pan and found the #6 connecting
rod crank journal badly scored and bearing lead worn away and missing and bits
of grit in what was left. I found sand in the #6 crank journal oil passages.
The owner said after the previous work was done the engine would not turn
over, so the "hack" proceded to sand the #6 journal with sand paper to provide
clearance and I guessed didn't clean out the passages afterwards. Fortunately
the engine wasn't run very long before they asked me to look into it. On
teardown, I found all the compression rings broken in several pieces and a
definite ridge at the top of all the cylinders. He had replaced all the rings
and didn't remove the ridges causing the new compression rings to break. The
engine had only an hour or two at most on it since the work was done and
should not have had a ridge on the cylinder walls in such a short time. The
engine ran fine except for the rod knock. Due to the short run time, the
broken compression rings didn't have time to damage the piston upper ring
lands either. Hope this helps. BTW the engine is still running fine to this
date.
P.S. I also found the front crank pulley (damper) loose on the crank shaft
and crank nose badly worn. A fix to keep from replacing the crank shaft was
to have the crank shaft nose knurled when I had all the connecting rod
journals turned down. It made for a nice interference fit when I put the
damper-pulley back on. I don't remember if the journals had to be .010 or
.020 ths. undersized but the clearance was right on using "plasti-gauge" at
rebuild. It was .003 ths. if I remember right.
Larry Wendland
'67 BJ8
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