BB Flywheel Question: How to identify???

[Haney]

How do you tell a Netural Balanced flywheel (internal blanced motor) from a flywheel used on a cast crank motor (external balance)?   I have a flywheel 130 tooth, but can't find a part number on it anywhere.  I want to use this on a 1971 440 internal balanced motor and want to make sure it is not an external balanced unit.

Thanks,

[Chryco Psycho]

the casting # is the same balanced or not , if you look at the block side of the flywheel there will be a few holes approx 3/4" - 1" in diameter if it is for a external balanced engine but even that is a problem as the 400 , 440 HP with 6 pack rods & the 440 cast crank were all different + to add to the confusion all the small blocks used a 130 tooth flywheel as well so you can add the 340 cast crank & 360 to the mix & both have unique balancing as well , the Mopar Performance engine book has the diagrams for drilling the holes for the different weigth patterns so you may be able to match it that way if it is for a balanced engine

[Haney]

Thanks Chryco! 

So If I am unsure, I guess I could have a competent machine shop check it to make sure it is neutral balanced?

I am not a BB guy at all...  All my experience is with SBs so this may be a stupid question.....

I can use a 130 tooth flywheel on my BB if I use a BB bellhousing for a 10.5" clutch.  Right?   I don't have a bell housing yet and I am thinking about buying one of the new castings from Brewers Performance.   This will go behind a 1971 440 with a 23 spline 833.

Thanks again.

[Chryco Psycho]

yes the 130 tooth flywheel & clutch will bolt onto a big block , , I use the 10.95" clutch for max surface area & power holding capability

[ShelbyDogg]

Even if it was from another internally balanced motor, If you didn't buy it new it could have been rebalance by the old owner. Take it to a balancer to have it checked out.   I had a 440 so out of balance once that it broke the tailshaft off of a 727 at high speed.

[Haney]

Thanks for all the input.  I will have it checked.