AvRog

When is the weight added to the flexplate on a 70 454? Do you have to do a motor balance procedure like a tire installation?

Phil Zell

All 454's came externally balanced from the factory. just bolt it on and go

AvRog

Thats the part I don't get, when you buy a new flexplate, how do they know where to put the weight? Would they not need to spin my motor to figure that out, or is the weight just to balance the plate itself? If the latter is true, then why is the 427 plate not balanced?

gofastvette

Is it not true that the flywheel only goes on 'one way indexed by the crankshaft so they will all be the same

larrywalk

The imbalance weight, when welded to the flexplate during manufacture, is located by reference to the seventh hole.

gkull

On an externally balanced motor the flex plate or flywheel on one end and the damper on the other are either drilled or weight added to balance the motor as a complete unit.

If you replace any one of these components you will need to have it made the same (weight balance) as the part being removed.


Internally balanced motor use neutral weight dampers and flex plates or flywheels

AvRog

So if my flexplate is cracked, i would need to buy a new one then buy a weight the same as the the previous one and then weld that to the new plate?

...Roger...

http://www.amazon.com/Allstar-ALL268.../dp/B003BZX1OS

AvRog

Thanks Roger, thats what I don't get. The presence of a weight suggests a balance, how can they put a weight on the flywheel before they know the balance of the engine it is going to be installed on????

gkull

Roger, You can't just buy a one size fits all. No two engines are exactly the same. But factory balance jobs are just somewhat close, because they don't care on mass produced junk production motors.

AvRog, I would have a quality shop help you in making something close to what the original was.

...Roger...

I've put several standard balance flex-plates on stock 454s and they did fine. I'm sure a better balance could be achieved by an engine shop but most don't want to pay what it would cost.