i just swapped an 85 302 in my mav and i had to replace the flywheel with a 50oz 157 teeth to fit my belhousing. when i turn the car on it doesnt vibrate but when i accelerate a tiny bit the car starts shaking..we changed the harmonic balancer and it still vibrates so im guessing its the flywheel?
if you rev it up in nutrual does it vibrate? if you hold it at different rpms can you get it to vibrate? does it only vibrate when you start to move? does it keep vibrateing the faster you go or just when you start out?
When its in park and I rev it just a tiny bit it starts to vibrate When I try driving if barely touch the throttle it won't vibrate but after that it starts to vibrate
if it vibrates when you rev the motor with out the car moving its a motor problem. if it only happens when your moving then chances are its a u-joit phaseing problem.
Are you certain its "Vibration" you are feeling and not a missfire??? Does the engine idle smoothly???
Have you recently changed the engine, balancer or flywheel? What was the last thing you did before it started vibrating?
paulS i was doing the swap from my 250 to the 302 so i bought an engine from an 85 f150 we were trying to bolt it on to my c4 but couldnt because the flywheel was 164 50oz so we bought a 157 50oz and bolt it on and ever since the first time we turned it on it would vibrate above idle.
i would suspect that your flywheel is not 50oz (its happened to people on here before) or that motor is not 50 oz. it could be possible that the motor may have a problem with compression. it would be a good idea to do a compression test and a leak down test to assess the mechanical condition.
Did the trans/torque converter bolt up to the engine without any difficulties?? IE: Didnt have to force the two together(draw them together with the bell housing bolts) Are you useing a new torque converter or the one from the 250???
