Good news, the engine vibration seems to be gone/acceptable. I installed the replacement flywheel counterweight and that reduced the vibration about 20%. Then I tuned the carb with a vacuum gauge and that reduced it another 70%. I initially had the corner idle screws out 1.5 turns per Holley. With that, I only had 4hg of vacuum. I adjusted the screws until I had 11hg of vacuum at idle and 20hg at about 2500 rpms. The corner idle screws are at about 1/2 to 2/3 of a turn out from fully seated.
I believe the remaining 10% is just me not being used to a big cammed stroker motor. I visited my painter on Saturday and he has a 68 Camaro with a 383 stroker and has as much vibration in the steering wheel at idle as I do now.
My engine temps are much better as a result. It sits about 190-195* at idle.
I have 3 current issues I’m working on:
-after about minute of idle, the exhaust starts to “pop” every few seconds. I guess the pop would be considered a backfire
-when I let the clutch out and I’m coasting, the car surges/bucks
-when I shut the car off, I have engine run on for a few seconds. I can get around this by cutting it off in gear. But I’d rather fix it properly.
I feel that these issues are tied to the carb and I need to continue to tune it. But, I don’t really know what to do next. I did retorque the header bolts and sprayed carb cleaner around the carb hunting for a vacuum leak, but didn’t get an rpm change.
Daniel
Last edited by DWC; 08-25-2019 at 06:52 PM.
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