Bad Vibrations - The 1947 - Present Chevrolet & GMC Truck Message Board Network

rctylr · 05-09-2010, 03:51 PM

Hello again folks,I have a new problem.I rebuilt my 454 myself and it runs beautiful EXCEPT I have a mild vibration in the engine.I put an edelbrock cam with matching intake.could the cam do this? if not how about the flywheel.Im not sure if I put the same one back on.If a 350 SBC is the same then that could be my problem as I realize BBC is externaly balanced.If the flywheel is the problem is there anyway to check without removing the trans? I appreciate your comments .Rick

James McClure · 05-10-2010, 07:19 AM

Rick, did it do this before the rebuild? No, the cam ect. won't make it vibrate, but it will make the eng "lope" at idle. Is it an auto trans? If it is you will be able to see a rather large counter weight welded to it. Also, the crank should have a pin that locates the flywheel\flexplate in the proper position. Some small blocks are pined some aren't. If it's not pined, it should be. You could have the right flywheel\flexplate but have it in the wrong position. I would pull the trans. The flywheel should have an extra hole in the bolt circle for the pin, just align that with the extra hole in the crank, fire it up and see if it still shakes. Harmonic ballancer is also different, but I don't think a small block one will fit over the crank hub. Let us know what you find. Jim

05-09-2010, 03:51 PM	#1
rctylr Registered User Join Date: Apr 2010 Location: calgary can Posts: 10	Bad Vibrations Hello again folks,I have a new problem.I rebuilt my 454 myself and it runs beautiful EXCEPT I have a mild vibration in the engine.I put an edelbrock cam with matching intake.could the cam do this? if not how about the flywheel.Im not sure if I put the same one back on.If a 350 SBC is the same then that could be my problem as I realize BBC is externaly balanced.If the flywheel is the problem is there anyway to check without removing the trans? I appreciate your comments .Rick

05-10-2010, 07:19 AM	#2
James McClure One shot, one kill. Join Date: Dec 2007 Location: Saratoga Springs NY Posts: 859	Re: Bad Vibrations Rick, did it do this before the rebuild? No, the cam ect. won't make it vibrate, but it will make the eng "lope" at idle. Is it an auto trans? If it is you will be able to see a rather large counter weight welded to it. Also, the crank should have a pin that locates the flywheel\flexplate in the proper position. Some small blocks are pined some aren't. If it's not pined, it should be. You could have the right flywheel\flexplate but have it in the wrong position. I would pull the trans. The flywheel should have an extra hole in the bolt circle for the pin, just align that with the extra hole in the crank, fire it up and see if it still shakes. Harmonic ballancer is also different, but I don't think a small block one will fit over the crank hub. Let us know what you find. Jim __________________ 1984 K20 350M engine with 465,000 miles. Well, it's finally done!! Almost 2 years of work, but it was really worth the effort. Little stuff left to do is mount winch, wet sand & buff out and build belly pan\running boards. Body work takes lots and LOTS of beer!!!! God, Guts and Guns made America and God, Guts and Guns will preserve it! The worst thing you could do is get into my sights, but that don't matter, you'll never know it, cause you'll never hear the shotJim or Paladin whichever you choose.



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