blkc6z51

Need help with vibration – have 63 327/300hp with P/G the vibration starts at 1200rpms
And go’s up to 2000rpms I have not taken it past 2000. I have taken all belts off it still
does it, have replaced the H/B it still does it, have run it with the TQ/converter disconnected it still does it. Can it be the flex plate could it have the wrong one. The motor only has a few miles on it.
Thanks for any help.

66jack

Almost sounds like the cam is going flat or is flat.

Tintin

Could be a bad motor mount or loose...

OCS1667

drive shaft

67*427

Was the motor balanced at rebuild? It sounds like you have and internal out of balance condition in the motor.

It's been a long time but I BELIEVE the only balance weights on that flex plate are to balance the plate itself... thus they are small. If the flex plate has a large weight on it, it might be for an externally balanced motor. Is it not the original flex plate?

Tell us about the rebuild? Stock parts?

Steve

L78racer

look at your flex plate. you may have one for a 350? it could have a big weight welded to it or a bunch of holes drilled to counter balance it....

Frankie the Fink

Everybody jumps to the 'worst case' right off. If the motor only has a few miles on it then its been rebuilt. If its been rebuilt it means the plug wires have been R&R'ed.
Make d@mn sure you check the firing order - crossed up plug wires will make you nuts and 'rock and roll' the car sometimes and seem nearly OK at other times.

Who knows ? You might get off easy on this one.

blkc6z51

Well this motor was rebuild 12 years ago and has just been setting till we put it in this year. as far as we can tell from the invoice is stock.

Could be a bad motor mount or loose..
Motor mounts are new I did check them.

drive shaft Does it in park.

Is it not the original flex plate? NO it is not Trans. shop gave it to us.

look at your flex plate. you may have one for a 350? it could have a big weight welded to it or a bunch of holes drilled to counter balance it....
No weight that I can see does have some small holes drilled in it.
How do you tell if it's for a 350??

crossed up plug wires will make you nuts
I will check the plugs but I have done that a few times.

Frankie the Fink

You don't say, but if the car's plug wires have sat idle for 12 years...they may have deteriorated (almost certainly) and may be 'leaky'....that's as bad as crossing up the wires.

DansYellow66

Or a shorted plug wire. A missing cylinder creates a nice shake in the motor.

Randy G.

I have a set of brand new plug wires that came in a complete harness set from LL for my '54 that drove me nuts a few months ago. It is a newly rebuilt motor and the car ran like crap. I finally went to Napa and picked up another set of plug wires out of frustration just to see if that was the problem. It was.

My '57 fuelie has a similar (but not obnoxious) vibration. And on mine it isn't the plug wires.

If you can confirm it's not missfiring (through ignition wires, plugs, valve adjustment, carb lean or rich condition), can confirm you have the right flex plate and harmonic balancer (and the is balancer not loose on the crank) and can confirm it is not an accessory (water pump and/or fan) then it might be an internal engine balance problem. But to be a vibration that noticable someone would have really had to screw it up when putting it together (mixed up brands or weights of pistons or rods, etc.).

RG

Frankie the Fink

Probably that big mouse nest near the #3 crank journal throwing it off some...

blkc6z51

Plug wires are new.

blkc6z51

We'll check every thing on the list, have checked some, can you tell me
how do you tell if it's the right flex plate for 327 or 350.

MikeM

The only OEM flex plate that makes any difference is the 400 sb and the 454's. There's nothing wrong with a 350 flex plate as long as it's neutral balanced or if it was balanced to your engine assembly.

"Vibrations" have different meanings to different people. Is this vibration a shake, a buzz, a rattle, rough running engine, or what?

Since you've disconnected the torque converter and the accessory drive belts and you still have the problem, it could be an engine balance problem (including the flywheel), and engine missfiring or even an exhasut pipe grounded.

You need to give a better definition.

blkc6z51

Well you can fell it in your foot when you start to accelerate and in
the steering wheel. Guess I have a lot to check out.

MikeM

I see you have a '63. They commonly have more vibration than later models due to no rubber body mounts. The steering column is one place you can really feel it.

66jack

Hydraulic lifters?

one or more could be the problem..

blkc6z51

One more on the list to check, thanks for your in put.

jdk971

if you feel it in your right foot, i would start with the drive train. engine
first. jmho jim