Flex Plate , stock or JW

[dynoman]

I need to know if I can use the flex plate off of my old motor on the new motor ? My old motor came with a JW flex plate #93007X which according to JW's web sight it is " internal balance 160 tooth Ext. balance " what ever that means , is it internal or external ?? My new motor has a stock flex plate that came with it . I would like to use the JW if I can, This is holding up my motor install !! Thanks, Sam

 

[Steve V]

If it was neutral balance it would not have that weight on it. So it is setup for external balance(stock).

 

[pacecarta]

stock crank is external so the flywheel and balancer is part of the balance
forged cranks are usually internal balance (some were external) which means the flywheel and balancer don't contribute to the crank balance and are neutral balanced
the JW wheel you have in pic is an external balance , and should work with stock crank or external balance forged

 

[dynoman]

So I'm good to go with the JW on the new motor ?

 

[pacecarta]

im not psychic
is your new motor external balance IE stock crank
if so yes it should work
heres the disclaimer
ideally if you have any piston other than stock and if the crank was rebalanced being external balanced the crank should have been balanced with the flywheel and balancer you planned to run

 

[dynoman]

Yes , stock crank and came with stock flex plate but not stock pistons. I bought the long block from Mike Dopkins ( m233roller) , I'll check with him. Thanks, Sam

 

[dynoman]

I PM'd Mike and he said that the motor was balanced with the flex plate and balancer that came on that motor , so that's what I'm using. Could I use that JW plate on a new build or should I just sell it ??? Thank, Sam

 

[pacecarta]

if the flex plate you got with the motor wasnt altered but rather just on when balanced you could run the JW

 

[dynoman]

Motor is back in the car now with the stock flex plate that it came with . I think I'll hang on to the JW for my next motor project.

Posted from the TurboBuick.Com mobile app

 

[turbodave231]

Save yourself some time and avoid the guesswork. Take both flexplates to your local machine shop who has a crank balancer. They can spin both and tell you if the balance is close. If not, they can (or should) be able to match the JW to your stock balancer.

Dave