What would be considered normal engine vibration given the following set up:
472 hemi using:
-JE pistons
-440 source rods, stroker crank (rotating assy pro balanced)
-Aluminum heads, stock valve gear
-comp cam 292 hydraulic flat tappet cam
-stock mopar flywheel (pro neutral balanced)
-centerforce dual friction clutch (factory neutral balanced)
-fluidamper
-new m/p ignition, holley street avenger 870 carb, carter high vol. mech fuel pump
-factory style hemi exhaust manifolds and alum dual plane manifold
- new factory style hd rubber transmission mount
-Lakewood bell housing- dialed in
-schumacher front mounts for a 70 barracuda
-both alternator and steering pump disconnected
-
I have had ongoing vibration problems- some of which I have sorted out. One was pinion angle and I also chucked the polyurethane transmission mount in favour of a rubber one.
Using a helper in the car (me underneath) revving it in neutral, and with my hand placed on different parts of the engine there is no major vibration felt until about 5000 rpm and then there is moderate vibration felt between 5000 and 6000 rpm. This is mostly felt on the base pan and the a833 transmission, and up through the pistol grip shifter.
A couple questions:
-Is this normal vibration, that will happen with any engine of this size and set up?
-Are the schumacher mounts contributing to this? will they cause the engine to transmit more vibration to the body?

When i place my hand on the Bell or reasonably close to the vibration damper, or anywhere on the block it is still noticable but less. If it is normal I will leave well enough alone. I was considering pulling the flywheel and clutch and having them rebalanced, but I am not sure what to do. 2 engine builders told me they have very little problems with factory neutral balance of centerforce clutches.
What do you think?
Thanks
Glenn

A vibration in neutral will have to be in the engine,flywheel, clutch or trans. If it only happened driving, I'd say check the u-joints, pinion angle or mounts,.

As I said in my post, there were multiple vibrations.
-One was incorrect pinion angle , which I corrected
-One was an out of balance tire, which I corrected
- That left some serious vibration coming up through the sterring wheel, floor and shifter. It was suggested to get rid of the polyurethane transmission mount, which I did, and made the the car much better, however there is still some.
This question is not as much about where it's coming from and what is causing the vibration, but what's normal at 5500 rpm for a stroker hemi with schumacher mounts. If the natural dynamics of this set up will cause a moderate vibration at high RPM and the general feedback I get indicates that, then I probably won't tear the car apart this winter
Thanks
Glenn

I recall the Fluidampers can get the fluid stacked in one spot and cause it to be out of balance at certain RPMs

Maybe try a Rollmac

Rollmaster maybe. Forget the name but it is made in Aussie.

John, I guess that's what I am wondering. If a big 550 hp stroker engine is strapped to a dyno and ran up to 5500rpm, what type of vibration will come out of the thing? What's normal? I am talking about what you feel with your hand. I know that's not a very technical way of testing. All I can say is a very fine light vibration (a little rougher than an electric razor)starts around 5000 rpm and becomes somewhat more noticable from 5000 to 6000. I'm sure a stock stroke 340 balanced with light weight pistons will not have the same dynamics as a stroked hemi ...again what's normal... for a stroked hemi?

Not sure if I agree with your logic on the 318 vs the 3000 hp motor there John, however, that's precisely the question I'm asking.... any other comments?

my dad used to say he could tell if an engine was running right by looking at the antenna on the car as it idled. If it was steady, it was running good. if it was shaking, it needed looking at.

Of course, that was with a stock engine. once you throw a big cam and high compression at it, that antenna shakes like a son of a gun.

There gotta be some engine builders out there with opinions and comments

I have a 472 Hemi also. It has 11.5 compession. Everyting else sounds about the same. It has no vibration any where. Sounds to me that you might have something grounding out. What kind of engine mounts are in it. I have schumacher. Hope that helps.

'67
I have schumacher mounts too. Are you suggesting an electrical ground?
Have you had someone rev the car while you were under it?
Glenn

What I meant was like the rear engine mount, exhaust system. Anything like that. Sorry it tokk so long to get back.