I bougth a internally balanced fully forged 396 kit, it comes with the balance sheet, i rebuild with the cam in my sig. and when i turned on the car I have big vibrations like a big cam car, now i go back to the stock cam because it's going to take me more time to buy alll the valvetrain for that cam.
my problem is, now with the stock cam, when i deaccelerate the engine makes a little vibration, like an unbalanced engine, why does it seem that the engine is unbalanced?????? could it be because of the flywheel weight, do i need the weight or not??? or an aftermarket flywheel??? or it's something else????

 

I am no expert, but I have always heard not to pay the vendor to balance it. Always pay a local shop to do it. (Thats what I hear) Now I am working on only my first motor, but it needs to be balanced by someone you trust.

 

ok thanks, but now i need to discard all posible solutions, before take out the parts and balance it again in a local shop.

 

after i got my car back with the new motor (internally ballanced as well) i was getting a nasty vibration and found out the weight was still on the flexplate so i ended up getting a new flexplate which was then neutrally balanced along with a neutrally balanced harmonic balancer and the problem was solved. lt1s i believe are externally balanced which means they balance the engines rotating assembly with the ballancer and flywheel/flexplate on the motor. being that your motor was internally balanced the balancer(dampner0 stock and the flexplate/flywheel also stock needs to be neurtally balanced or zero balanced

hope this helps because i had a similar problem

 

When you got it balanced was it with the flywheel and blancer pulley on or was it just internally. Even if you have an internally ballanced motor you should still have it balanced with the flywheel and balancer pulley installed. Just to make sure it's all gonna balance as a whole.

 

If its advertised as "internally balanced", it should run smoothly with a neutral balanced flywheel, and a neutral balanced damper. The stock damper on the LT1 is neutral balanced from the factory. The external balance weight is all on the flywheel or flexplate. That weight needs to be removed for an internally balanced application.

 

they send just the crank, rods, pistons, metals..., balanced, my flywhell still have the weight, the damper it's the stock one, so what it's best? remove the weight form the stock flywheel??? or buy an aftermarket that don't have weight???

 

i'm looking a flex plate at 0 balance and i cn't find it! any summit number or other place??

 

Call J&W in Florida,they have one.
Take the weight off of yours should make it a neutral balance.

 

Take a stocker to a shop and have it zero balanced. They will probably knock the counterweight off of it, spin it, and give it back to you. I had this poblem when I done my stroker. The engine was built for an auto car and I stuck my stock, untouched, flywheel on it. It didnt feel to pretty