engine vibe with ford racing aluminator

[KXT]

well we just installed a new aluminator motor in a 99 cobra. it started on the first try but when we went for a test run we noticed a vibration at idle but gets worse at 1000 rpms and is present at almost every RPM. The vibration is present when in nuetral and in gear. the harmonic balancer came on the new motor and the clutch and flywheel were torqued to specification. Motor mount and k member bolts have been checked also. The engine doesnt seem to be misfiring (pulled each coil and they seem to be firing fine) and cant find any vacume leaks. Anybody know something to check?

 

[KXT]

YouTube - jared's 99 cobra - aluminator - VIBE

The vibe is extremely hard to see in the video. Evident easy on the K&N filter housing.

 

[VEE EIGHT]

Looks a lot like an unbalanced crank

 

[trinity_gt]

When you assembled the clutch to the flywheel, did you leave the dowels in place on the flywheel to align the pressure plate? The bolts alone are not enough to align it properly and if it's not centered, it'll vibrate like crazy.

Did you have the flywheel resurfaced and if so, did they put the dowels back after machining?

I had a shop around here replace my clutch some time ago and when I went to pick it up it had a pretty nasty vibration as you're describing. I knew there was something wrong the moment I started it. I gingerly drove it about a mile before turning back and telling them to take it apart and fix it.

 

[bdcardinal]

what was the build date on the aluminator? there was an assembly issue for a while where they were not properly setting crankshaft endplay and it was destroying the motors. check out svtp for a thread about it.