vibration in BB convert problem
Thread Starter
Drifting
Joined: Jul 2015
Posts: 1,765
Likes: 254
From: Catlett VA
vibration in BB convert problem
There is more vibration transmitted thru the steering wheel with the car idling, standing still and warmed up than I believe should be present on my 68 convert. The NOM 454 has a mild hydraulic cam, but the idle is not radical and the engine itself does not appear to be vibrating. The motor mounts are stock type in good condition and the rag joint on the steering column is new. Bolts holding the steering wheel to the firewall and instrument panel frame are tight. Trans is 4 speed but the steering wheel vibrates even with the car in neutral. If I place my hand on the car fender or any body part, there is little or no perceived vibration- but- the steering wheel vibrates enough to be visible just looking at it. I know the 454 has substantial mass, but other big block cars I owned with 454s did not shake the steering wheel like this. Any suggestions to decrease the shaking or do I need to get used to it?
Le Mans Master
Joined: May 2003
Posts: 8,877
Likes: 3,556
From: Fernandina Beach FL
2023 Restomod of the Year finalist
2020 C3 of the Year Winner - Modified
Your not the only one-
See if you have the updated bracing-
https://www.corvetteforum.com/forums...and-shake.html
I have an article that talks about the designers wanted the "targa" top versus the t-top- and GM went w/ the T-top to lessen the cowl shake...
See if you have the updated bracing-
https://www.corvetteforum.com/forums...and-shake.html
I have an article that talks about the designers wanted the "targa" top versus the t-top- and GM went w/ the T-top to lessen the cowl shake...
Thread Starter
Drifting
Joined: Jul 2015
Posts: 1,765
Likes: 254
From: Catlett VA
So I guess I am not the only one with the problem. My October 67 build car does not have the cross braces from the trans tunnel to the cowl, but does have the flex frame and hood-popping problems. What was that old time sled name? Flexible Flyer.
Le Mans Master
Joined: May 2003
Posts: 8,877
Likes: 3,556
From: Fernandina Beach FL
2023 Restomod of the Year finalist
2020 C3 of the Year Winner - Modified
HAHAH- my 68 vert back in the day- had hoodpins!!!
Racer
Joined: Jul 2007
Posts: 459
Likes: 56
From: Southeast Ohio
vibration
You might check to make sure that the flywheel is for a 454 and not for the motor that was previously in the car. While a 427 or 350 flywheel will physically bolt on to a 454, there will be a vibration.
Racer
Joined: Nov 2007
Posts: 410
Likes: 45
From: Wisconsin Rapids wisconsin
The 454 is an externally balanced engine. If you used a small block flywheel you will need a balance plate.
Thread Starter
Drifting
Joined: Jul 2015
Posts: 1,765
Likes: 254
From: Catlett VA
I could put a glass of water on the air cleaner with the engine running and it would not spill a drop. Engine balance is not the problem. The lack of cross bracing on the early build 1968 car sounds like the problem that is amplifying a minor vibration. (BTW, in 1972 I put an un-balanced Hays forged flywheel on a 289 Ford engine and installed it in my 1966 Mustang fastback, not knowing a counter-balanced flywheel was needed. I KNOW what an unbalanced engine runs like. Even that little small block literally shook the car to pieces).
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