Fired up my 65 mustang!!!! help w/ vibration

Not the Autorx Frank · Mar 24, 2005

For those of you that know of my stang restoration. Well, its running. Have to rejet the carb. its way fat... Timing is dead on. Adjusted valves. Still have a vibraton @ 2000 rpms. Havnt put it on the road yet.

Is it normal to have some vibration untill the rings seat? ton of blowby. enough to push the dipstick out from the pressure. had to install a pcv LOL..

when the motor was built it was blueprinted and balanced. just lookin for a little guidance ...

crossbow · Mar 24, 2005

I assume you checked this frank...but how do the motormounts look? If their loose or damaged, you'll get all sorts of crazy NVH.

Of course if you went to solid mounts, that would explain things too

.

brianl703 · Mar 24, 2005

Is the harmonic balancer OK?

Chris142 · Mar 24, 2005

quote:

Originally posted by brianl703:
Is the harmonic balancer OK?

That was my 1st thought. Do you have a 302 with a 289 balancer?

Even a fresly rebuilt engine should not push the dipstick out with blowby.

theguru · Mar 24, 2005

quote:

Originally posted by Not the Autorx Frank:
its way fat...

Is the car overweight or "phat"

TheLoneRanger · Mar 24, 2005

Congrats on getting it running, Frank. No, ring seating shouldn't make a vibration. I think you've got a small problem somewhere. Could be something as simple as a bad plug......

Gene K · Mar 24, 2005

Make sure the Balancer and Flywheel/Flexplate match the crfakshaft you have. If the engine was balanced you may want to question the builder about which balance factor he used and if it matches your components.

A miss caused by the mixture and/or timing can also appear to be a vibration.

If the cam is a bit on the warm side it may not be fully on the cam at 2000 rpm resulting in the vibration.

PS High Performance engines are sometimes "Overbalanced" for high rpm operation. This can reduce smoothness at low rpm.

Gene

Not the Autorx Frank · Mar 24, 2005

quote:

Originally posted by Gene K:

If the cam is a bit on the warm side it may not be fully on the cam at 2000 rpm resulting in the vibration.

Gene,

Elaborate please. I'll check and make sure flywheel balance matches damper etc....I added a pcv and cured the dipstick jumping. Motor mounts are brand new...my mech said that we needed to jet the carb down quite a bit.

Man I hope I don't have to pull this motor out. Just the thought of that makes me cringe..

Not the Autorx Frank · Mar 24, 2005

Another question. wouldnt an internal balancing problem show at all rpms and get worse the higher you went?

thx everyone.....

loudist · Mar 24, 2005

Dipstick blowing out?
Do a compression test on all cylinders, especially a leak down test.

Not the Autorx Frank · Mar 24, 2005

pcv cured the problem. it was pcv less when we fired it. still gettin a little blue smoke but nothin scary.

Ugly3 · Mar 24, 2005

quote:

Originally posted by loudist:
Dipstick blowing out?
Do a compression test on all cylinders, especially a leak down test.

Ditto cubed!

loudist · Mar 24, 2005

quote:

Originally posted by Not the Autorx Frank:
pcv cured the problem. it was pcv less when we fired it. still gettin a little blue smoke but nothin scary.

I'd still do the compression test, a dipstick blowing out without the pvc hooked up is still not right.
You posted that it was rebuilt, rings could have been broken on install, it happens.

Gene K · Mar 24, 2005

quote:

Originally posted by Not the Autorx Frank:

quote:

Originally posted by Gene K:

If the cam is a bit on the warm side it may not be fully on the cam at 2000 rpm resulting in the vibration.

Click to expand...

Gene,

Elaborate please. I'll check and make sure flywheel balance matches damper etc....I added a pcv and cured the dipstick jumping. Motor mounts are brand new...my mech said that we needed to jet the carb down quite a bit.

Man I hope I don't have to pull this motor out. Just the thought of that makes me cringe..

If you used a hotter cam ie Hi-Po 289 or Aftermarket you may still get some reversion at a rpm beyond which you can discern any lope. You may still feel it as a vibration.

Nice to hear you got it fixed.

Gene

TheLoneRanger · Mar 25, 2005

Frank, I'm sure you're aware that there's two different firing orders for the 289/302, depending on the cam used. I doubt if it would even start if the firing order was off, though.

There's also two different weights for the harmonic balancer, but then I can't imagine an engine shop making a mistake with this either.....

Might be the compression blowing out the spark on a faulty plug, at a higher rpm.....you could check them with an ohmmeter; the resistance measured from the connector to tip should be around 5K-6K ohms. Wires should be about 5K-8K ohms per inch.

I'd double check the simple things first.

Not the Autorx Frank · Mar 25, 2005

Thanks guys for all the chiming in. I have a good punch list now. I will re check all the obvious too..

I really appreciate everyone taking the time to guide me.

I'll be back when this is sorted out and let yall know what it was.

Mitch · Mar 27, 2005

quote:

Originally posted by TheLoneRanger:
Frank, I'm sure you're aware that there's two different firing orders for the 289/302, depending on the cam used. I doubt if it would even start if the firing order was off, though.

There's also two different weights for the harmonic balancer, but then I can't imagine an engine shop making a mistake with this either.....

Might be the compression blowing out the spark on a faulty plug, at a higher rpm.....you could check them with an ohmmeter; the resistance measured from the connector to tip should be around 5K-6K ohms. Wires should be about 5K-8K ohms per inch.

I'd double check the simple things first.

It is 302 /351W that has the different firing orders

jsharp · Mar 27, 2005

IMO, something isn't right. Over the years working with dozens of rebuilt engines I've never seen one that was put together correctly that had excessive blowby from the first time it was started. Once the assembly lube was burned out they didn't smoke either. A few minutes running and it should be burning clean and you shouldn't see much of anything out the breather, even with no pcv valve...

Not the Autorx Frank · Mar 30, 2005

ok an update.....

had a leakdown and compression test done..... everything checks out ok. went in and re-adjusted valves after getting it good and warm. smoothed it out some... the vibe is not violent at all just a little jitter around 2000 rpms. dead smooth at idle and higher rpms. still gotta jet the carb down a bit. all in all getting better. I think Gene may have been on to something with his comment.

"reversion at a rpm beyond which you can discern any lope. You may still feel it as a vibration. "

I'll let you guys know how it does under a load when i put it on the road after we jet the carb and align it.

thx again everyone!!!!!

Not the Autorx Frank · Mar 30, 2005

quote:

Originally posted by TheLoneRanger:

quote:

Originally posted by TheLoneRanger:
Frank, I'm sure you're aware that there's two different firing orders for the 289/302, depending on the cam used. I doubt if it would even start if the firing order was off, though

Click to expand...

quote:

Originally posted by Mitch:
It is 302 /351W that has the different firing orders

Click to expand...

This is true for stock engines. However many cam manufacturers go to the "later" firing order for the 289/early 302, to promote engine longevity and smoothness.

The 15426378 order tends to hammer out the front main of the 289, because both front cylinders fire sequentially. The 13726548 order is much better. Makes me wonder why Ford didn't figure this out sooner.....?

yeah i get ya...this has the standard 302 order...i know most roller cams use 351 order but this one keeps standard order....
I'm learnin a bunch through this project.

Fired up my 65 mustang!!!! help w/ vibration

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