Vibration
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Joined: Jun 2018
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Vibration
Guys I have a 73 454. Previous owner installed roller rockers. Car is a 4 speed. It has a terrible shake vibration at idle and going through gears. Seems to smooth out after 4 th gear. It it shakes enough to shake the steering wheel while sitting still. Harmonic balancer has been replaced with a high end one thinking that was the issue. It wasn’t. Any ideas? bent crank? Bent pushrod? Or what do y’all think? Thanks.
Le Mans Master
Joined: Sep 2001
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From: Unreconstructed, South Carolina
Harmonic balancer for 454 has an EXTERNAL balance ... maybe it Improperly had a neutral balance OR an external for a 400 sbc on it ... either will cause it to vibrate/shake ... then it seems someone has replaced it ... maybe replacement balancer/damper is also improper.
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it had original balancer on it. Replaced it with one from summit
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Le Mans Master
Joined: Sep 2001
Posts: 7,739
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From: Unreconstructed, South Carolina
427-402-396 are series of BBC that do Not have external balance.
How do you KNOW those parts are/were original to car when car was manufactured?
How long have you owned car?
When did vibration begin?
Was it vibrating when you bought it? Or begin afterward? Or do not know?
How do you KNOW those parts are/were original to car when car was manufactured?
How long have you owned car?
When did vibration begin?
Was it vibrating when you bought it? Or begin afterward? Or do not know?
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Le Mans Master
Joined: Sep 2001
Posts: 7,739
Likes: 630
From: Unreconstructed, South Carolina
HF Thirty dollar laser temp gun ... https://www.harborfreight.com/121-in...ter-63985.html
check each exhaust runner a couple inches from head.
check each exhaust runner a couple inches from head.
Le Mans Master
Joined: Sep 2001
Posts: 7,739
Likes: 630
From: Unreconstructed, South Carolina
Suppose I shouldn't assume ... but I did assume you've already checked by pulling off one plug wire at a time ... if it stumbles, it's a good cylinder ... if it doesn't stumble, it's probably bad.
Thread Starter
Advanced
Joined: Jun 2018
Posts: 81
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427-402-396 are series of BBC that do Not have external balance.
How do you KNOW those parts are/were original to car when car was manufactured?
How long have you owned car?
When did vibration begin?
Was it vibrating when you bought it? Or begin afterward? Or do not know?
How do you KNOW those parts are/were original to car when car was manufactured?
How long have you owned car?
When did vibration begin?
Was it vibrating when you bought it? Or begin afterward? Or do not know?
Le Mans Master
Joined: Sep 2001
Posts: 7,739
Likes: 630
From: Unreconstructed, South Carolina
OP
We are trying to help you narrow this down ... there's a process.
A 454 damper is External balance and has a pronounced counterweight... here's a pic of a Pioneer pn DA4541 ... you can clearly see & feel the counterweight on the REAR of this damper
https://static.summitracing.com/glob....jpg?rep=False
https://www.summitracing.com/parts/pio-da-4541
We are trying to help you narrow this down ... there's a process.
A 454 damper is External balance and has a pronounced counterweight... here's a pic of a Pioneer pn DA4541 ... you can clearly see & feel the counterweight on the REAR of this damper
https://static.summitracing.com/glob....jpg?rep=False
https://www.summitracing.com/parts/pio-da-4541
Race Director
Joined: Jul 2015
Posts: 13,082
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From: SW Florida.
You can see the casting number on your flywheel along with the counterweights with splash cover removed from front of bell housing. Get somebody to bump starter while watching flywheel. Take phone. Snap pics.