Motor Shakes badly

[ss68396]

Hey guys,,,

Just got the 454 in the car and  fired it up yesterday. I got the timing set to 0degs right now..But here is my problem.....The car shakes madly when you rev it up anywhere past idle. The thing I see is it looks like the balancer is warped. What I mean is it is rubbing on the water pump pully just slightly. I notice by the paint be rubbed off. Also it looks liek when the car is running you can see the balancer has a slight wobble....How can I fix this? Also this motor had a auto attached and I replace the flexplate with my flywheel. Would this cause this motor to shake this bad?? PLease help i want to cruise with it as it has been 5yrs since I had the chance to drive it down the road.

Thanks
Jay

[JohnZ]

454's are EXTERNALLY balanced, and require both a counterweighted balancer and counterweighted flywheel; if a normal neutral-balanced flywheel and balancer like those on a 396 or 427 are used, it'll shake like crazy. If you have an 8" balancer and it rubs the water pump pulley, you have the wrong water pump pulley for that application.

[ss68396]

Thanks John. I have talked to a few guys here and it seems that the concensus is that i put the 396 flywheel on. I will pull it off and get a 454 flywheel. Also I will look into the pulley also.

Thanks for your input I really appreicate it.

Sucks cause i got everything bolted up nice to. Is it a tough job to remove and replace the flywheel in the car or would it be easier to pull the motor AGAIN...LOL

[dutch]

Thanks John. I have talked to a few guys here and it seems that the concensus is that i put the 396 flywheel on. I will pull it off and get a 454 flywheel. Also I will look into the pulley also.

Thanks for your input I really appreicate it.

Sucks cause i got everything bolted up nice to. Is it a tough job to remove and replace the flywheel in the car or would it be easier to pull the motor AGAIN...LOL

Does the balancer appear to have an actual wobble for part of its rotation or is it just always that that close to the water pump that it rubs slightly?
If it actually has a wobble could the crank snout have hit anything in transit anywhere (machine shop etc) to bend it and that is causing the balancer to wobble? If other things check out keep it in mind.
Probably the balancer and /or flywheel as others have mentioned but the bent snout came to mind because a friend bent his while trying to get his motor in and didn't notice it and it sounded similar to the way his ran afterwards... Randy
 

[ss68396]

Randy,

I think the balancer is slightly warped as the rubber is bulging in some spots and receeded in others. I will be pulling it off and taking it to a race shop tomorrow to have them look at it.

I will take pictures to show the closeness of these items(balancer and pully)

Also I did find a brand new GM Flywheel part#3993827 which is for this motor a 78. Not a bad price either....From teh Stealership only 250.00 cdn. Not bad since the closet and cheapest aftermarket was 235cdn and a week away from me. So I will be pulling the motor again tonite and removing these 2 items and try again tomorrow.

Thanks to all for your help.

[hotrod68]

Zero degrees initial timing isn't good, either, Jay...crank about 10-12 degrees into it on the balancer after you get that fixed and you'll find it will rev a lot more free, respond much better, and run a lot smoother. Your initial timing is way retarded. Hope this helps.