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Once more I turn to the collective wisdom of the Brickboard.
The car is a 1966 122S with a B18 of unknown origin, muffler shop exhaust with a resonator and a "quiet" muffler, stock intake and pancake filters.
At higher RPM (52MPH in 3rd and right at 70MPH in 4th) there is a resonant howl that is about to drive me nuts. VERY LOUD. And, it has to be the most irritating frequency imaginable, somewhere around 200Hz, by guess. If I keep in the throttle for just a few hundred RPM more, the resonance disappears and the car gets as quiet as it was before the resonant point.
The exhaust system is not touching anything. All hangers are tight. Small exhaust leak at the manifold gasket. But otherwise quiet.
It is definitely RPM dependent. Is it possible that the blowby I have been experiencing (pushing oil into the front carb) has anything to do with this? I am completely out of ideas.
Anyone got any ideas? Even better, how do I stop it?
--
Mr. Shannon DeWolfe -- (I've taken to using Mr. because my name tends to mislead folks on the WWW. I am a 50 year old fat man ;-) -- KD5QBL
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