C1 Egnine Vibration

[Joe D.]

My 61 has a vibration in the engine. It seems to be a balance problem. It is fine at idle, around 2000 rpms it starts. I took off the front clutch bellhousing cover and looked at the flywheel when the car was running and it seemed to be running true. If the flywheel was out of balance would I be able to see it when it was running? Thanks asa always, Joe

[John H.]

Re: C1 Egnine Vibration

Joe -

Probably not the flywheel - they don't go "out of balance". Take the fan belt off and try it again to eliminate the water pump/fan/clutch or generator/alternator as contributors.

[John O.]

Re: C1 Egnine Vibration

Hi Joe

Also check harmonic balancer and engine mounts and bolts for loosness.

John

[Verle R.]

Re: C1 Egnine Vibration

Joe,

How long have you noticed the vibration, for a long time or just recently?
If recently, have you done something to the car in that time frame?
If so, review what was done.

If not, refer to the other suggestions.

Your post suggests you have determined the vibration to be associated with engine speed, not car speed.

Check external components first, balancer, water pump, pulleys, generator bracket, motor mounts, bellhousing bolts transmission bolts.
After you eliminate all those you can consider investigating the clutch and transmission.

Keep us posted.

Verle

[Terry D.]

Re: C1 Egnine Vibration

Does it do it setting still at 2000 or going down the road?
If only down the road check weights on wheels, driveshaft etc.
Terry

[Clem Z.]

Re: C1 Egnine Vibration

check the clutch disk and pressure plate because they are more likely to be out of balance than the flywheel.

[Joe D.]

Re: C1 Egnine Vibration

It does it while the car is just sitting. It idles fine. When I increase the rpms to 2000 it starts to vibrate and as I increase the rpms so does the vibration. Thanks, For your help, Joe

[Joe D.]

Re: C1 Egnine Vibration

I should have mentioned that my engine was just rebuilt. It only has 100 miles on it. The guy who rebuilt it thinks that it my be the flywheel. He does not think that it is internal. Thanks, Joe

[Wayne P.]

Re: C1 Egnine Vibration

Your rebuilder should have balanced the rotating assembly. I just torn down a 63 I bought recently with the same problem starting at 1500 rpm. It had two odd rods in it and had not been balanced. Glad I tore it down as everything else they did was suspect. I'm doing it completely over including the crank, which was cast instead of forged and had been welded on.

[Mike McKown]

Very likely the problem.

The engine should have been balanced, expecially if your rebuilder changed pistons. If you're using the same flywheel as before and it didn't vibrate, the same flywheel wouldn't be the cause now.

[Joe D.]

Re: Very likely the problem.

He did say he balanced the engine and he thought it was not internal. I will try your suggestion. I guess it would be easier to try the external parts first. (and cheaper) Thanks, Joe

[John Walker]

Re: Very likely the problem.

Joe; I have found also that you can rotate the pressure plate and solve many vibration problems.

[Timothy B.]

Re: Very likely the problem.

Joe,

I had my 63 vette motor balanced and not only did they balance the internal rotating assembly (pistons rods crankshaft) but they also wanted the harmonic balancer and the flywheel and pressure plate. When I got it back there was a mark on the flywheel and pressure plate bolt holes showing where to bolt the pressure plate for proper clock position. Your engine builder should remember this if the motor was properly balanced.

[Clem Z.]

never balance the flywheel and pressure plate

as one unit because if you have to change the pressure plate the engine will be out of balance and vibrate.

[Mike McKown]

Took the words right out of my mouth.

I don't remember you saying you installed a new clutch but if you did, the pessure plate could be suspect if it wasn't balanced.

You should also look for exhaust being grounded to the frame but this is a long shot under the symptoms you describe.