427 vibration - wrong Flywheel????
December 5th, 2018, 9:11 AM
#1
CF Beginner
Thread Starter
Join Date: Dec 2018
Posts: 1
Likes: 0
Received 0 Likes
on
0 Posts
427 vibration - wrong Flywheel????
I am an experienced car builder/restorer but no experience with Chevy BB engines....
If someone put a 454 flywheel on a 427 wouldn't the engine shake like a hula girl even at idle?
I have a 68 Corvette with 427 - Just got it.
There is an engine vibration starting around 2700 and gets worse as the RPM increases.
My thought was clutch cover out of balance
Upon inspection the engine has a 454 flywheel. (Note I was told engine rebuilt in 2012)
Q: Does the engine have the wrong flywheel or did they swap in a 545 crack during the rebuild?
I do not have access to the builder.
Before I tear into this, I'm looking for opinions.
The transmission is out, is there any issue just firing it up without the clutch? If not vibration then it was the clutch....
If vibration then I pull the pan and inspect the crank...
Thoughts???
Thanks all!
TK
If someone put a 454 flywheel on a 427 wouldn't the engine shake like a hula girl even at idle?
I have a 68 Corvette with 427 - Just got it.
There is an engine vibration starting around 2700 and gets worse as the RPM increases.
My thought was clutch cover out of balance
Upon inspection the engine has a 454 flywheel. (Note I was told engine rebuilt in 2012)
Q: Does the engine have the wrong flywheel or did they swap in a 545 crack during the rebuild?
I do not have access to the builder.
Before I tear into this, I'm looking for opinions.
The transmission is out, is there any issue just firing it up without the clutch? If not vibration then it was the clutch....
If vibration then I pull the pan and inspect the crank...
Thoughts???
Thanks all!
TK
April 8th, 2019, 12:27 PM
#2
CF Beginner
The 454 engine was externally balanced (as was the 400 small block)! The 427 was internally balanced. If I recall correctly, the offset weight (on an automatic trans flex plate) has to weigh at least 4 ounces! I am pretty sure that a 283 to 350 (which are all internally balanced engines) flywheel of the same external dimensions will work. You may want to be mindful of the overall weight of the flywheel though.