Technical Chevy 327 crankshaft question can not find a flywheel that fits! HELP!!!!

Here are photos of a flexplate on a 283 crank with the dowel removed, the ‘plate has been indexed six times.
I will follow up with more info.

 

There are too many Doubting Thomases here so they shall go unnamed, but you guys know who you are anyway.
I was not a stellar student in high school, I preferred to sit in the back of the class when I could, but I did pay attention in my math classes and that served me well as a machinist for General Motors.
Initially I checked a flywheel with a dial caliper and the numbers told me that the holes on the bolt circle are equally spaced and have a center to center distance of 1.790. With the c-c distance known next I checked that the bolt circle was in fact concentric to the centerline of the crankshaft and on the aftermarket Gotha 'wheel I was checking I see an error of .006, the b/c is shifted .006 from the register diameter of the flywheel, and it is shifted away from the dowel location. The bolt holes check .450 and GM f/w bolts are .434-.435 diameter.
Granted I was not using a coordinate measuring machine but I did the best I could and I stand by those numbers. Some of the "facts" and comments here surprised me, and a couple of you guys made me sit back and think "Really???, that guy believes and actually posted that?" I did expect an off the wall comment from one guy and he came through as usual

 

It is fine to disagree, but making a blanket indictment of the veracity of the claims or character of others, without naming them, or the claim, is a bit craven.

Being a former GM machinist is all well and good, and it is a nice thing to have under your belt, and you should be proud of that.

But then again, being a current, third-generation GM Engineer is a nice thing, too.

 

Rather than being known as craven I will just say that those that mentioned it flat out would not fit unless it was indexed with the dowel hole really caught me off guard, some of them seem to have had quite a bit of Chevy engine experience. I don't believe you suggested, as others did, that the flywheel had to be aligned with the dowel hole but if you somehow think I impugned your character that is something I cannot help.

 

Thank you for doing your to be constructive in this matter.

We are trying to solve problems here, and so far, it has not been solved.

 

Not 50 years worth, but also my experience.
And the bleat goes on...

 

Now that everyone has spoken their piece about their experience, does anyone have a solution?

 

Measuring both crank flange and flywheel bores should tell the story.
However, 'splitting hairs' by trying a different flywheel on the O.P.'s crank, then both flywheels on another SBC crank will supply the needed 'quotient'.
Whatever's left... might make it right.

 

waiting for the Paul Harvey"the rest of the story" Yes,anyone that has used a crank button for an In and Out box,Bert transmission or a direct drive powerglide knows that the bolts are equally spaced on a Chevy!!. Oldsmobile crankshaft shares the same CENTER HOLE as the Chev,but has 2 holes slightly off set so it can only go on 1 way.I have put a Tilton Triple-disc clutch and flywheel made for Chevy on an olds 330-455 by egging out 2 of the holes on the flywheel [Tilton uses the stock flex plate for eternal balance and starter drive] OP possibly has fly wheel drilled for Olds???-would be strange,but this wole thread is strange

 

Wait a minute Fordors,
I see the deal with your pics,,,,,,that is a stick shift crankshaft .
It’s evident from the greased pilot shaft bushing inserted into the crank.
Obviously the flexplate will work on that ,,,,,the bolt holes in a flexplate were oversized to begin with,,,for use with an automatic crank .

Lol,,,,just kidding everybody,,,,,,it makes no difference,,,,I was just making it all up !
I thought a little humor might bring this thread back ,,,,and not let anyone get too excited .
We’re all friends here,,,,and I enjoy learning a lot here,,,from everyone !

Tommy

 

A clutch alignment tool would have been easier...

 

I think you photoshopped the pictures!! Just messing with you!

 

The pin hole is likely a registration hole for crank machining at the factory, end of story. It would make zero sense to have anything but a true bolt circle to mount the flywheel, or it would not be a bolt circle, by definition.

 

The Holden grey motor in my avatar has 4 flywheel bolts and a locating dowel. 2 of the bolts are offset to create balance. If the dowel isn't there you keep turning the flywheel until the 2 offset bolts line up. It's probably not a real bolt circle.

 

The pic below was copy/pasted from an earlier post in this thread. You can see clearly see that this flywheel spent MANY years with the dowel pin hole on the flywheel lined up with the dowel pin hole on the crank. I personally have once seen a dowel pin in place. Was it factory or something someone made up? I have no idea. The idea or intent behind the two holes (whatever that may be) was good enough for GM, it's good enough for me and it was good enough for whomever installed the flywheel shown below. The apparent fact that the flywheel can be rotated without issue is meaningless to me as I will continue to line up the holes as (I assume) GM intended. That being said ... where the hell is the OP?

 

Probably laughing at everybody here trying to help .
He just joined the group recently and only has 7 post .
Probably a ghost just making this crap up to see how we will debase ourselves trying to help,,,,LoL .

Tommy

 

4 pages and 107 posts......

 

As a collective, what would be a guess as to the number of people who have NEVER experienced this problem, far more than posted here, add me to that list.

 

Maybe it's a nut problem that has nothing to do with bolts.

 

I never meant to piss anyone off or imply that the OP is stupid. When I try to help people I just figure they don’t have much experience. I hope I did not run him off or hurt his feelings. I know sometimes I can sound like a Richard (no offense meant). That was not my intention. I just figured if there was any runout in the bolt circle of the flywheel or crank and they stacked up. Rotating the flywheel would help.

 

I wonder if the crank is in backwards

 

Huh???.....

 

No… it’s got to be in upside down for this to happen…

 

Righty loosey lefty tighty?

 

Yeah, like Chrysler lug nutz....

 

Bryan >>>So update. Got the old flywheel back and here is a picture of the flange without it being on the stand. Tried rotating it as well... still to no avail. >>>

Might help to stand the block on its nose. Then let gravity help you align the heavy platter instead of trying muscle it on sideways. It'll fit.

 

Why not visit a local machine shop and have the holes oblonged to match the crank. I really don't see another solution.

 

And then the flywheel would somehow fit the crank better? Posted that for the flywheel installation, not whatever followed that. As I stated, I've never worried about aligning the dowel holes, and flywheels always went right on. But I'm old and forgetful.

 

Got a flex plate from the chain parts store. Didn’t fit. Got another one, fit a little better.
Rat tail file fixed it.

 

I keep coming back to this thread several times a day. I need to get a life. But this is too much fun. Frustrating for the OP, but fun.