Just bought a 1991 GT. Previous owner did a new 347 shortblock with trick flow heads a nice redone supercharger along with a new tremec trans. When first test driving the car it had a nice vibration you can feel in the car around 2k to 3k....pretty heavy. Since getting the car home you can feel it at idle as well and revving it. He said he did a new centerforce clutch with s SVE billet flywheel and you can see a new harmonic balancer on it. Wanna get this fixed as there's only 500 miles on almost everything a dont wanna ruin it. You can feel it heavy in the shifter while driving and just in neutral reving. Where and how do I start?
Engine Vibration
- Thread starter Carlini17
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A lot of fancy stuff there. Because you don't know the car I would bring it to a Mustang Master if you think you find one. The previous owner would/should have fixed it. Could be anything in my opinion.
- Mar 2, 2015
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Sounds like wrong flywheel...should be 28oz and not 50oz. Most folks just order one for a 302 and that won't work in most cases.
( I'm out of hibernation....was gone for a few )
( I'm out of hibernation....was gone for a few )
You can get the part # off the balancer , and see if it's 28oz or 50. Maybe ask the guy if he has the reciepts. Kind of stinks that you could take it apart, and still have the problem.
He has nothing. He got most of the stuff from jobs owed/money/favors and buying the car and kindnof marrying everything. Everything he said was legit except the vibration which he doesn't know how to fix. From top to bottom the motor and trans is new. Even a new Canton oil pan. Couldnt pass on it. Was too reasonable of a price. Driving me nuts. Would hate to pull the trans and go through hell. Really fells like the flywheel.
Mr.Kelley
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If it is the flywheel you want to fix it before running it again. I had a vibration same as you describe on a 351C in my 72. It lasted about 1500 miles before beating the front main out and destroying the block. When I pulled it out I discovered the flywheel was from a 240 six cyl.
The 347 kit could be internally balanced. Neither stock weight would be correct then. And looking on Summit, that info is not always listed on the site. If he has the receipts, you should be able to contact the kit supplier for the info.
And Yes, the harmonic balancer and flywheel need to match.
And Yes, the harmonic balancer and flywheel need to match.
That’s good to know, but it could fit on the snout of any Windsor style crank.
Here is what you are looking for.
Here is what you are looking for.
Hey, let's do a little investing before tearing this thing apart,
Since you know little to nothing about the engine (verifiable facts) I would start with firing order, the HO firing order does not play well with a non HO cam. Engine vibration is a symptom.
I would start there.
Since you know little to nothing about the engine (verifiable facts) I would start with firing order, the HO firing order does not play well with a non HO cam. Engine vibration is a symptom.
I would start there.
I don't know what pre 94 means 
I mean I know it's 'before 1994' but the sbf (302) firing order changed with the 5.0 HO way before 1994,
The firing order you posted is for a non HO 5.0.
I would find out what the firing order your engine is supposed to use.
I mean I know it's 'before 1994' but the sbf (302) firing order changed with the 5.0 HO way before 1994,
The firing order you posted is for a non HO 5.0.
I would find out what the firing order your engine is supposed to use.
No, roller cam does not mean HO. The camshaft determines firing order. If you pull the spark plugs and see what order the cylinders push air out on the compression cycle, you can determine firing order. Or you can switch the spark plugs around and see if it runs better.
When you say 3-4000rpm, does it go away at higher rpm?
It does sound like the flywheel.
If you look on lmr's site, it would appear an SVE flywheel comes with weights for 50oz, 28oz and i'll assume zero with no weights. Could you ask the previous owner which weights if any he installed?
Been quite a while since i bought a flywheel, but i think i'd rather just have a factory balanced one than one you add the weights yourself.
While in general i don't like cheap parts, i really have a distaste for putting them in a location hard to undo.
It does sound like the flywheel.
If you look on lmr's site, it would appear an SVE flywheel comes with weights for 50oz, 28oz and i'll assume zero with no weights. Could you ask the previous owner which weights if any he installed?
Been quite a while since i bought a flywheel, but i think i'd rather just have a factory balanced one than one you add the weights yourself.
While in general i don't like cheap parts, i really have a distaste for putting them in a location hard to undo.
Hard to say if per day goes away because all that rpm the car is ripping and running. But it does it at a dead idle no clutch engaged and engaged. I'm guessing the flywheel as well. Car is as described, block, heads etc. Ripped it apart as I had a brand new trick flow intake to go on.
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