I got a very helpful message from Bob Kitterer about engine balance and it
reminded me I hadn't posted the final resolution.
For those of you who trust everything your motor shop does, my recent
experience may have some value. I had a bad feeling on picking up the newly
rebalanced rods for the Austin A35 motor and took them to the lab for a little
recheck on an accurate balance.
It turns out that the balancing shop had totally zoned out and forgotten to
finish the rod balance. Phone call, lunch truck, whatever, it didn't get
done. They were apologetic and redid them correctly at no charge. I didn't
ask for center-of-mass balancing on the rods as it will be a fairly low power
948 in a street sedan. The motor had a nasty harmonic vibration at 2500 rpm
when I first got it. Turns out the #4 rod was a replacement from some PO
rebuild and was 17grams heavier than the heaviest of the others. 17grams!
I'm sure that it will now be a much smoother street motor.
To the extent possible, double check things that will end up deep inside an
engine you don't want to remove again soon.
Glen Byrns
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