The engine in my '75 B raps at idle. It sounds and acts like a rod knock.
Load at idle, but disapears at a higher engine speed, or under load. So,
after dropping the pan and finding nothing blatantly wrong I decided to be
cautious and replace the rod bearings. Although the old ones showed som signs
of wear they really weren't bad at all. No signs of burning or anything wrong.
After geting it all back together and starting her up I'm still getting what
sounds like a rod knock. A loud rythmic clunking that varies with engine speed
and starts to go away at about 1100 RPM. I'm concerned and confused. If I
can't
pinpoint the source of the noise I can't be sure my engine won't be damaged.
The engine was rebuilt in the fall of 92, with a Mallory distributor, MSD,
Piper BP285 cam, double row timing gears and chain, and a Weber DCOE.
I do autox with the car, and it has been used hard. But it's never been above
6000 RPM, the MSD has a built in rev limiter. Does anyone have any odeas where
this clunk could be coming from ?
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