Chevy 400 Build

[LilSpann601]

Do all of my parts have to be balanced at one time? Or can I just have the crank balanced then i install it into the block...then next week have the rods and pistons balanced then install them??? I just have a bad idea about dropping off a sh*t load of brand new parts

 

[mebe007]

they get balanced together as a rotating assembly generally.

 

[LilSpann601]

i dont mean to be asking stupid questions. I just dont understand the reason to take all my parts up there. What will the machinist do ? Whats the balancing process

 

[mebe007]

Theres no stupid question. thats how you learn.

heres a little read for yah
http://www.rpmmachine.com/engine-balancing.shtml

 

[drogg1]

The crankshaft has those large hunks of metal or counter weights to counter act the momentum of the rod and piston hitting top dead center and hitting bottom dead center. If they weren't there, the engine would shake itself to bits. The balance process involves adding or removing material in either the counterweight or the rods in order to achieve a near zero balance. That's sort of the general idea. So, without the rod/piston assembly, the crank cannot be balanced and vice versa.

 

[chevy2480]

YEs everything has to go together. They make sure all pistons and rods are exact in weght. Then they take into account the weight of piston with rings and rod as one. Then at that point they either add or remove weight from crank as needed to counter balance the weight of piston, rings and rods. Same goes for balancer and flex plate. It is a must they go together.

 

[LilSpann601]

Ok. Well ive just about got everything but the flexplate, balancer, and pistons. The machinist will tell me next week what size pistons i will need. As for as flexplate and blaancer ive seen some cheap $40 flexplates on ebay..should i just get flexplate and balancer off ebay?? Do they piston rings need to go to the machine shop during the rotating assembly balance?

Thanks for all yall help

 

[chevy2480]

Not all the rings just one piston setup. Just dont mix up the first and second rings.

 

[mebe007]

Ok. Well ive just about got everything but the flexplate, balancer, and pistons. The machinist will tell me next week what size pistons i will need. As for as flexplate and blaancer ive seen some cheap $40 flexplates on ebay..should i just get flexplate and balancer off ebay?? Do they piston rings need to go to the machine shop during the rotating assembly balance?

Thanks for all yall help

You can get an Sfi approved flex plate from summit for around $60

 

[LilSpann601]

Ok. Well ive just about got everything but the flexplate, balancer, and pistons. The machinist will tell me next week what size pistons i will need. As for as flexplate and blaancer ive seen some cheap $40 flexplates on ebay..should i just get flexplate and balancer off ebay?? Do they piston rings need to go to the machine shop during the rotating assembly balance?

Thanks for all yall help

You can get an Sfi approved flex plate from summit for around $60

Does it matter what size harmonic balancer I get?