Runout on Flywheel

[KMcCullah]

Took the flywheel back to the hanger and put it on my level block and spun the flywheel around checking every 90 degrees at a 12" diameter. I had .004" TIR.

Jim- I don't understand how your measuring the run out of your flywheels. Maybe a granite surface plate is what your describing?  The only way I've ever checked the face run out of a flywheel is by having it installed on the crank that it was going to be running on. Before you shoot the grinder I would suggest bolting it on the crank that it's going to be running on and checking the run out that way. 

[JimNolan]

KMcCullah,
I've done that, comes out the same. My crank is good. This is the way I check it. I've got a 4" X 4" steel block that I machined smooth when I was working. I place the center of the flywheel on that and draw a circle inside the flywheel flange onto that chunk of steel to keep the flywheel centered as I rotate it. I place a 1" plunge indicator with magnetic base on a plate of steel beside the flywheel with the indicator on the flywheel. I rotate the flywheel to different degrees getting my results. It's foolproof and the results are duplicated no matter how many revolutions I make with the flywheel. That part of checking it isn't rocket science.
BTW: The second guy that ground it said it had been ground on a Blanchard also. He could tell by the marks. One thing I did notice about the two grindings, the first guy put a super smooth finish on the flywheel, the second guy left it somewhat more rough.

[Ranch]

My concern would also be with balance because a flywheel is suppose to be neutral balanced and now you may have .010 + on one side. I would think it should be pretty much parallel front and back face running true with the make up mounting face.  I'd have it checked and maybe recorded by them before you take that long drive again.  Somebody messed up; Good catch

[HolmanMoodyStroppeGang]

Had another thought for you Jim, for when the radiator cools down....I get that one

It wouldn't hurt to mic around the flywheel, to check the actual height or thickness, width, you know.

I'd use this as a double check to look for clues. Just measure from the machined face to the back of the wheel, maybe do it every inch or 2 to start

A nice tenth indicating micrometer, not calipers is what I would try. 

We have a guy who can also regrind the register area

Again, no way that you are getting crank shaft end play wandering in and out?

Wedge the wheel against  the bellhousing ears on the block with a tapered hardwood block maybe , creat a slight drag as you turn the wheel,,,push the crank back, or at least deflect the assembly consistently as you measure with a big screwdriver, etc.


Now you measured the crank flange run out, did you use a big faced tenth indicating indicator?

I'd look close there, and stone the areas I discussed

One good burr can kick a flywheel out of true, no doubt

Nice work

[JimNolan]

Before I made that 50 mile drive over there I checked my 390 cast internally balance flywheel the same way. I came out with .0005" TIR run out using same procedure. It had been laying around a few years and the face was discolored so I thought I'd get it resurfaced also. After the guy resurfaced the 410 flywheel he washed the table and his spacer that he put under the flywheel real good, mounted the flywheel, tapped it around until it turned concentric, locked it down and started grinding. I heard a chirp-chirp-chirp as the wheel began grinding and my heart sank. I knew then his Blanchard was off or I was off on the flatness I'd found on that flywheel. Sure enough, this morning I found out it when I measured it showed .002" TIR.
I've decided to put the 390 back in the 57 Fairlane  and I'll be using the cast flywheel the way it is. It would be nice if it had come out perfect but unless someone decides to drive my car and let the clutch out to where it only engages .001" into the flywheel I can't see trying to make it any better than what it is. And, if someone could ride the clutch that close on my flywheel I'd jerk them out of the car and beat them over the head with a feather duster anyway.
In all seriousness, I'm tired of messing with it and I don't care what it looks like on the crank. They don't resurface it on the crank. I did the best I could, the guy resurfacing did the best he could and I can't see driving all over the country having it reground until it has the thickness of cigarette paper trying to get it perfect.
If I ever use the 410 again or sell it I'll make sure to get the flywheel sent to another state to get it resurfaced.
Thaks guys, I'm just tired of dealing with it. The flywheel I'm using at .002" TIR at 12" diameter isn't going to kill me and McLeod said if I'd use the 500 miles they recommend driving it instead of racing it as soon as the new clutch is installed,  the flywheel wouldn't get eat up to begin with.