Mustangs of Illinois

I have been fighting a drone/vibration that starts at 1800 rpm. I thought it was when they put a 302 engine in that since it was wired not like 15426378 that it was a newer 302 and was suppose to have the 50oz balance weights instead of the 28oz balance weights. So I bought a harmonic balancer and flex plate. Got them put on today, and now I have a worse vibration. So in a few weeks when I get the time I will take it back to work and put the old ones back in and start over trying to find what is causing the vibration.

ANY SUGGESTION WHAT COULD BE CAUSING IT ?

So if anybody needs a 50oz flex plate or harmonic 3 or 4 bolt style 50oz. Contact me .
The flex plate looks like below....






New one on bottom...

barnett468

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install the right parts.

sit in the car and rev the engine to 1500 for 10 seconds then 2000 for 10 seconds then 2500 for 10 seconds . . if the vibration gets worse it is a bent flex plate or the engine is out of balance.

Mustangs of Illinois

It is out of balance badly with the 50oz weights...Maybe I need to check into how they mounted the exhaust to the car next.Might be transferring it to the frame?

I did order the 28oz weight to put in the new harmonic. Wish it was as easy to change the weight on the flex plate !

Check out the clearance on one of the bolts. Man was it fun getting out !

barnett468

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if you use the wrong damper or flywheel it will have a big vibration.

how can you or the shop not know what it should have?

Mustangs of Illinois

1st off.......

I did not build or install the engine.
I bought the car last year, it has always had the 1800 rpm drone.
I contacted Jasper Engines about the vibration. They can not look up the engine with the serial number I gave them ? Said it was to old of a number ?
But he said that in fact they did use either a 28 or 50 ounce balance weight. And has heard of this happening.
When I was replacing the wires and cap, I noticed the firing order was not 15426378 but one for a newer engine.
So I thought it might of been possible that whoever put the engine in could of used the old 28oz weights on a engine that should of been 50oz.
So I did a lot of research on the Internet and found that this has happened a lot when people have put a newer 5.0L in a older 302 vehicle and not installed the 50 oz weights on the engine.
So I decided I would try this repair and install the 50oz weights. It didn't work and made the vibration even worse

So I am trying to fix something that was not my fault in the beginning, and I have no way of contacting whoever the guy was that installed it many years ago. Not sure how long a go it was put in. As the car was in a over ten year restoration job.

So I will reinstall the 20oz back into the engine. And look for a engine vibration/drone that might be coming from the exhaust system ?

fastbackford351

If I were in your shoes and was that flummoxed I'd seriously consider starting over by pulling it out and verifying what parts you do have before it beats itself to death.

Mustangs of Illinois

I might just put up with it for a year. And in the mean time build my own engine the way I did with my 67 289. That engine was amazing, and I did it all when I was 18......