Vibration in new engine after 4000 RPM???

[Ackbar00]

Vibration in new engine after 4000 RPM???

Just got the new engine in the car and I am getting a pretty good vibration after 4000 RPM and up. I have tested this with the car sitting still, so I do not belive that it is in the drivetrain. Using a Stock Balancer on the new 306. Just had the flywheel resurfaced. Made sure all the obvoius bolts were tight. My brother thinks this could be due to exhaust resonance from the downpipe (I am running it open right were it curves to the back down the firewall). Was not doing this before the motor swap. Exact same combo as before, except it now has a F-Cam. I have a call in with the engine builder to verify that it was balanced to 50 for the stock balancer. But I would think that if it was balanced to 28 or 0, that the motor would break very quickly, could this be wrong? Any Ideas???

 

[mstangfrk95GTS!]

was the rotating assembly balanced??

 

[Ackbar00]

was the rotating assembly balanced??

I have a call in with the engine builder to verify that it was balanced to 50 for the stock balancer.

 

[87'GTstang]

How is the harmonic balancer standing up?

 

[Ackbar00]

How is the harmonic balancer standing up?

As far as I can tell, it is undamaged.

Still have not got to talk to engine builder yet (Even though they called me back ). Any other Ideas? To me, it fealls like I am holding on to a weed eater instead of a shifter.

 

[jeff1993]

Paul,

I have had a vibration with an improperly surfaced flywheel. However, the vibration was there at all times and did not start at a specified RPM. Have you heard from the engine builder? BTW, who is the engine builder? Get that thing done, I want to see it at the track!!!! Talk to you later.

Jeff