31 Coupe Engine Vibration

[TinCup]

Engine Vibration is a topic that appears quite often on the barn so here is yet another.

My coupe is an older restoration so exact details on the motor other than the pistons are 80 over are not available. Float A Motor mounts are used. Motor has little to no vibration 0-35 mph. Once I start to push it to the 40mph mark I start to get significant engine vibration. Once up to speed and I let off of the accelerator the vibration dimminishes but doesn't go away fully. Cars top speed is around 50 but that is a rare occurance. Is the key here that the vibration occurs during acceleration? Does this point more to flywheel than crank?

UPDATE: The vibration over the last 3 years has not gotten any worse or any better. It is consistent. A new clutch and lifters are in the works for later this summer so checking the center main and flywheel are on the list.

 

[billwill]

Engine Vibration is a topic that appears quite often on the barn so here is yet another.

My coupe is an older restoration so exact details on the motor other than the pistons are 80 over are not available. Float A Motor mounts are used. Motor has little to no vibration 0-35 mph. Once I start to push it to the 40mph mark I start to get significant engine vibration. Once up to speed and I let off of the accelerator the vibration dimminishes but doesn't go away fully. Cars top speed is around 50 but that is a rare occurance. Is the key here that the vibration occurs during acceleration? Does this point more to flywheel than crank?

lose flywheel

 

[Tom Wesenberg]

Has it always been like this?
Or, has it worn into this condition?
Have you checked the center main condition and clearance?

 

[Dennis L Oberer]

I have this in the coupe and my experience is engine vibration starts early and gets worse the faster you rev it.

Flywheel or clutch plate out of balance comes and goes depending on engine rpm. My flywheel was Waaaay out of balance and it got really bad at 45 to 55 but below that it wasnt very noticable...but on decel it vibrated all the time.

Dennis L Oberer
Green Bay WI

 

[Mitch//pa]

can we rule out something in the driveline

 

[Dave in MN]

I have a '28 CC pickup that used to vibrate terribly between 40 and 45 mph. That bare metal rear panel of the cab converted the vibration to sound and amplified it to the point I couldn't even hear my wife talking.....
I know...one could argue what's wrong with that!

I removed the flywheel and pressure plate, had the flywheel lightened about 8# and had the assembly balanced. The vibration is markedly less and the noise is greatly reduced. The vibration noise is less to be specific!
Hope my wife isn't a Fordbarner...
Good Day!
Dave in MN