200 vibration

[Anonymous]

: I recently aquired a 200 out of an automatic mustang. I cleaned it up, put on my flywheel and installed it in my 66 bronco. It runs really nice, but had a noticable vibration at 3000 rpms. I have adjusted the clutch, removed the fan belt and checked the harmonic balancer. Still the vibration persists. I noticed the automatic balancer (the one I am running) is very different from the 170 balancer. My 170 balancer is not in great shape so I would rather not run it. Any ideas??

TIA

 

[Anonymous]

You may want to ask this in the small six forum, but I believe that the 140 and 200 ran a different balance on the flywheel.

Jared

 

[MustangSix]

All our inline sixes are zero imbalance, so there should be no issues with going from 170 to 200. Are all the bolts in place?

 

[Anonymous]

I've got the exact same problem with my 200, as soon as you hit 3000 it just shakes you to death. ran it with just the flywheel, did the same, put new plugs in it and didn't help any.

 

[Ronbo]

Humor me here, back the timing off a tad and try running it up to 3K. See if the vibration moves or goes away. Just took a trip from El Paso to AZ and had the same problem. I have distributor issues I guess. When I reduced the timing it cleared right up.

 

[Anonymous]

I did back the timing off and it had no effect. Any other ideas?

 

[Anonymous]

Does your front seal leak? (bad bearing symptom) Or when you swapped engines did it get dropped or banged into anything (bent crank shaft?)
I recently backed off my timing. Spec calls for an advance of 6 BTDC and the performance handbook says to add about 5, so I'm at about 11 or 12 and it has reduced vibration and she doesn't seam to wind up as early.

 

[MustangSix]

I think you need to do some more diagnosis and figure out if it's a case of poor firing at certain rpm or if it is truly out of balance. If it is 3000 rpm, is it at speed or in neutral? If in neutral, is it the same vibration at speed?

A misfire that gets worse at speed will feel like an unbalanced condition. Are all cylinders firing? All plugs look the same? Have you used a meter to check plug wire resistance? Is the compression even across all cylinders? What does a vacuum gauge say?

Nothing you do with timing will cure an out of balance condition. You can get out of balance enought to cause a vibration by loosing a torque converter bolt or flywheel bolt. If it is only noticable at speed, it might be the driveshaft or U-joints.