I will comment on Bob's words of wisdom as I'm in the middle of updating my
engine again after last winter's update. Last winter, as I was doing the head
over, the temptation to drop the piston's, hone and re-ring was to much so I
went ahead w/o measuring for taper or out of round. Well suffice to say, my
problem of burning 1 qt per 175 miles degraded to 1 qt per 100 miles. Not a
pretty picture. The block's at the shop now and today the machinist said my
bores were 5-6 thousands out of round. Shouldn't have spend the $125 for the
specialty rings last year but done the measuring and paid the price. It's
only money honey......
Darcy Hunter
'73 TR6
No Easton, MA
From: "Robert M. Lang" <lang@isis.mit.edu>
Subject: Re: piston detective
Hi.
Dan Clancy's situation reminds me of some tidbits about engine
"rebuilding".
Many folks will "refresh" an engine by re-ringing and putting in new
bearings. I've done it myself a number of times. And with TR6 engines in
particular, it seems to be a conservative engine maintenance strategy.
BUT - it also means that you have to take the time to measure the bores to
make sure that they aren't worn and measure the crank to make sure the
journals are still rounds and so forth. Frankly, a lot of us skip that
step.
On the other hand, some folks tear the motor down and then bore it out to
whatever suits their fancy, regrind the crank (even if it was round to
start with) and so forth just because "you might as well do it while you
have things apart. Is this a valid strategy? I guess so, but all the
operations that you do cost money and _it is possible to do them wrong_.
In the latter case, the result could be reliability issues.
Which is the right way to go? BOTH WAYS. But YOU or a trusted designate
must check to make sure the stuff is done right. When you pay a shop the
extra cash to do a job, this is what you are paying for.
I just thought I'd toss this out there for the typical healthy debate that
this list seems to follow.
rml
p.s. the shop that originally did Dan's motor is out of business. Hmmm. I
suppose we can all say "no surprise there".
-
-----------------------------------------------------------------------------
-
Bob Lang Room N42-140Q | This space for rent
|