baffling 324 olds flywhee situation

Sparing the long story... I had a billet steel flywheel made for my recently totally rebuilt(and balanced) 1956 324 olds engine..... When I went to put it on I found out it doesn't fit!!! No matter hole it's clocked I can only get 5 out of 6 bolts to line up..the 6th is about a 32nd off.. I bring the flywheel to my buddies place ...it fits on a crank at his shop... Go back to mine to quadruple check.. No go... I drag out the hydro flywheel bolt holes are the same size.. And it fits my crank..... WTF!?! Were flywheels matched to the crank?
I spoke with a friend that worked for GM way back when and he seems to remember that they were, both internally and externally balanced??? Has anyone heard of this?? I'll be headed to the machinist that made the flywheel with the original and newly made flywheel saturday... But the suspense is killing me! If anyone has any experience with this please fill me in!!!

Thanks

Rich-

 

Pretty sure 57 up is an external balance engine. I have no clue if they changed the bolt pattern to prevent using the wrong one? ...but someone will answer that knows.

 

last time i had a motor balanced, they insisted on having the dampener and flywheel to balance it. granted this was a 455 olds, so it is not apples to apples.

 

They had the vibration dampner when the balanced the engine.....they never asked for the flywheel-

 

So. Did you go around both bolt circles with a caliper to see if you could locate an offset hole? Or if not confirm they are all on the same circle. I know I have gotten frustrated trying to find the offset hole.

 

I am not much help but you're not the only one to run into this.
I ran into the same thing when working with a 303 and 324 and don't remember the particulars but somewhere in the process I had a flywheel or crank that had a hole offset just a tad.
I'm sure someone on here knows the particulars and hopefully will weigh in.

 

There definitely are lots of things made with 6 holes on a X.XXX hole circle with one hole .030 offset so that the flywheel, or whatever, will always go back on the same way. But if that is what they are doing then all the cranks and flywheels should be that way. I made a custom pulley for some guys 392 dampener and it was that way. The flywheel I drilled for my '32 Plymouth was that way.

 

Then I'd seriously have a serious talk with the shop that did the balancing. Even if the flywheel is supposed to be zero balanced that doesn't mean that it was, is or that it will be once the rotating assembly is balanced. The flywheel that is/was supposed to be on the motor for final assembly should have at least been checked out for proper balance zero, counterweighted or otherwise.

-Bigchief.

 

The flywheel looks to have been zero balanced...
The back side is drilled in three spots- and it was made by a shop who specializes in this stuff... As is the engine builder-
unfortunately I'm not able to go to the shop till saturday-

 

Have both 50 303 and 58 371, both flywheels and crank flange have one hole offset about 1/16 inch. Sounds like your flywheel was drilled wrong.

 

that's what i thought.... than i brought the flywheel to my buddies shop and put it on a 324 crank he had lying around.. and it fit!!!!!!!
weird-

 

Maybe one crank was for a standard and one was for a hydro.I found out the hard way that there is a difference in the starter drive.

 

get a hold of goatroper02 on here He is a mmember and an Olds engine builder specialist His phone is330 544 4466..Good Luck

 

I play with Olds engines a little. Maybe this info from Bendtsens Transmission website will help you out:


Oldsmobile changed so much over the years that it would be impossible (without writing a novel) to list all the information here. The bottom line is that Olds changed their flywheel diameter and ring-gear tooth count 3 times. That means they have at least 3 different starters with different starter locations in the lower bellhousing (cast inspection cover). They also changed the crankshaft bolt hole locations. Most Olds engines have one bolt hole that is .070 offset on the crankshaft. Some Olds cranks have 6 symmetrical bolt holes. The different combinations are listed on my website. The flywheel that is included with this kit has one bolt hole that is elongated. This is to fit both style crankshafts. It is difficult at best to try to cover all the possible combinations you can find in the Olds motors. This (and the fact that they have extremely long block extensions) is the reason no-one has made adapters for these motors before.
The crank adapters we sell with this kit are made to fit on both style crankshafts. We have drilled one of the holes oblong so it will fit on both cranks. If you have the crank with the older, symmetrical bolt circle, it doesn’t matter how they are rotated when you bolt them on. If you have a crank with the offset bolt hole, you will need to line the inner and outer crank adapter and flywheel up so the offset bolt hole lines up with the holes in the crankshaft


Don

 

Thanks for this info Don....looks like i'll have the machine shop oblong a hole, and re balance-

 

hogged the ill fitting hole out with a rotary file, and put the damned thing on-
there i go again.....making mountains outa mole hills!

thanks for all the feedback-