In 15 years, I have probably accumulated in excess of 75,000 miles. There
were many summers when I would easily do 10,000 miles. (Don't tell my
insurance agent.)
In fact, I have had to rebuild the engine, but never because of
over-revving. The first time was because of an end plug which fell out of
the rocker shaft. This caused immediate oil starvation - spun a rod bearing
and scored the crank.
The second time was because of incorrect piston rings. They were ordered to
fit existing pistons marked +0.040. What I didn't realize until too late was
that the +0.040 was relative to some other car - not a TD. Thus piston rings
broke after 5,000 or so miles.
Each time the engine was reassembled, it has been carefully checked for
bearing wear. The very first time I had the engine out, I did notice that
the rod caps were oval. I had these reprofiled at the time (9 years ago). No
evidence of any undue bearing wear since.
The biggest contributor to nervousness of over-revving came as a result of
valve bounce above 4500 RPM. New valve springs didn't help. Finally this
last winter I had the rocker shaft and rockers professionally overhauled.
The Rocker Arm Specialist (Anderson, CA) built up the rocker faces,
reprofiled them, put in new bushes, moly coated the bushings, and built up
and turned the rocker shaft. Total cost - $85.00.
The engine is finally quiet, no more valve bounce (except above 5500 RPM -
70 MPH).
Sure, I would like to run at 3700 RPM at freeway speed, but I'm not unhappy.
Regards,
Lew Palmer
lew.palmer@uci.com
Lew,
In those 15 years, how many miles do you estimate that you drove the
car? That would help us judge whether the higher revs had a bad
effect. I am assuming you would have mentioned it if you had been
forced to rebuild the engine...
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