'27 Chevy

[12 X Rancher]

I recently bought a '27 Chevy with a 4.1 Buick engine +.060, cam and 4 barrel. The car has a great deal of vibration over 50 MPH. Much has been done, without improvement. Is there a Buick expert that may have a clue? I'm in Central Florida. Thanks

 

[49-blues]

What kind of engine and trans mounts are they?Was rotating assembly of the motor balanced?

 

[charlief1]

What kind of engine and trans mounts are they?Was rotating assembly of the motor balanced?

I will also add is it a manual or auto. If manual you may have an odd fire flywheel on it and that would cause the vibration.

 

[novaderrik]

does it have solid motor mounts on it?

 

[Sleeper-6]

Over 50 mph? I'd say you've been through 1 or 2 gears by then, and have revved through the normal rpm range. If it's smooth up until that point I'd look into the drive train after the trans. Check the balance on the tires and drive shaft.

Oh yeah .....show us some pics.

 

[JST A 6]

Over 50 mph? I'd say you've been through 1 or 2 gears by then, and have revved through the normal rpm range. If it's smooth up until that point I'd look into the drive train after the trans. Check the balance on the tires and drive shaft.

Oh yeah .....show us some pics.

I agree with this post. Take a good look at the driveshaft as I'm sure it's been modified to work with the Buick drivetrain.

He'll have to get a few posts under his belt before pics can be posted...

 

[12 X Rancher]

This is a motor problem, The mounts are the first place I want to go. They are solid. The trans is turbo 350 and the rear is Corvette. It hangs on the road like a Vette, suspension seems real good. If I can figure out how to send a picture I would. The previous owner had done a lot of troubleshooting before I got the car but he did not reengineer the mounts. Thanks for your interest.

 

[12 X Rancher]

How do you identify an odd fire flywheel. He has replaced the flywheel and I have a new one in the garage. This is an even fire engine

 

[12 X Rancher]

The engine was purchased through a NAPA dealer and is +.060 I doubt if it was balanced.

 

[charlief1]

The engine was purchased through a NAPA dealer and is +.060 I doubt if it was balanced.

If you don't have the correct balancer it will have an issue with vibration. The 4.1 uses a slightly bigger chunk on the hub to accomodate for the larger piston. I hate to say it you need to take the engine apart and have the internals balanced.

How do you identify an odd fire flywheel. He has replaced the flywheel and I have a new one in the garage. This is an even fire engine

I'd take the new one and have the guts re-balanced with the new flexplate and balancer for sure.

This is a motor problem, The mounts are the first place I want to go. They are solid. The trans is turbo 350 and the rear is Corvette. It hangs on the road like a Vette, suspension seems real good. If I can figure out how to send a picture I would. The previous owner had done a lot of troubleshooting before I got the car but he did not reengineer the mounts. Thanks for your interest.

Get rid of the solid mounts for sure if you want a better ride but if you stomp on it the drivers side will tryto seperate. Bad design unfortunatly. I would also have the drive shaft balanced to make sure it's good.
As far as posting a pic you have to have 10(?) posts before you can. Keeps the spammers out.

 

[JST A 6]

The car has a great deal of vibration over 50 MPH.

This is a motor problem

Not trying to be argumentative at all, but wouldn't a motor problem be more relative to a certain RPM vs. vehicle speed? That's why some of us were thinking driveshaft & wheels...

 

[UnderdogGN]

vibration

Drive The Car To 60 Mph, Put It In Neutral Foot Off The Gas, Vibration Gone You Know Its A Motor Problem, Vibration Stays Its In The Driveline.

 

[86GN-862+2]

I'd say driveline problem. Is the driveshaft yoke going into the transmission according to specs? I had this sort of vibration and the yoke was "dancing" around in the transmission tail housing/shaft.

 

[12 X Rancher]

I'll take a look at the tailshaft, I get a good deal of vibration when the car is sitting still in neutral at higher RPM. I drove it last night and it was tollerable to 52 MPH after that the stick started rattling and it got a lot rougher. Stay in touch, Thanks for the ideas. Sam

 

[charlief1]

If you're getting vibration without the car moving you need to rebalance the engine for sure. The vibration at higher rpm proves it. Sorry.