Background: 396 L34, recently rebuilt and dyno'd. Engine extracted once after rebuild due to "rod knock" that turned out to be loose flywheel bolts. Can you believe I forgot to torque them........ graemlins/clonk.gif
What I have now is a bit unnerving. At >1800 RPM or above, in any gear, light acceleration loud knocking. It is difficult to determine if the knocking occurs under heavy load as engine/exhaust is relatively loud. When I first heard this I thought it was predetonation. I have retarded the timing, and disconnected the vacuum advance and no change. Out of gear in nuetral I can get a brief noise at 1800 - 2000 RPM but not anything like it is in gear (under load). I have removed the inspection plate and verified all flywheel and torque converter bolts are tight. I am at a loss.
One additional piece of information, this only happens after warm-up (180+ degrees). I run Castrol 20W-50 oil. Oil pressure is good (40-60lbs).
My question is could it be something in the torque converter/tranny?
Can I run the engine without the torque converter connected (no load) without damaging anything to eliminate this as a possibility?
Any other things to check would be appreciated.

Can I run the engine without the torque converter connected (no load) without damaging anything to eliminate this as a possibility?
Any other things to check would be appreciated
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Yes you can, just make sure to wire back the converter so it doesn't ride (vibrate) forward on you when your revving the motor.

This is actually what I wld do if in your shoes to pinpoint that noise. Make sure to be under the hood and bringing your rpms up by the carb throttle linkage to better pinpoint.

Good luck and post back your findings...

-Greg

Thanks Smokumchevy. After I posted that question I thought, with a manual tranny there is no load with the clutch engaged doh..... I probably won't get to it for a day or two. Had serious hail storm(s) last night and have spent the entire day cleaning up from that mess. I will post further info as it is available. Later...