So I'm in the middle of my 383 build and my rotating assembly came with a flexplate. This is an int/ext balanced rotating assembly (hence why it came with a specific flexplate).

My problem is that I'm using a manual trans (t5, also built by me) so i need a flywheel. This is a SCAT 9000 rotating assmebly and i am unable to get in contact with scat (called and emailed multiple times) to ask which flywheel i should use. On their website they dont sell flywheels, only flexplates and balancers. So my questions is, what the hell do i do?

Do I find out which is the right balancer from scat to use? and use a neutral balance flywheel (Again, i cant get in contact to get this information from them)

Or do i buy a flywheel from somewhere else thats balanced right and get a neutral balancer?

This engine is already built besides oil pan and distributor/wires. So the last thing i want to do is have to rip it apart to get a flywheel balanced to match the rotating assembly.

Also, any difference with balancing an engine with a flywheel or with a balancer/damper?

 

Make it internally balanced with Mallory slugs

 

Like i said, I have everthing except the oil pan and distributor/wires assembled. I DONT want to take it apart to have the crank balanced.

 

GLWT

 

You don't state if it is 1 pce or 2 pce RMS; a more important factor in determining the correct version

No such thing ;
it is either internal balance or external ( 400 ci crank based )
All internal balance engines use a neutral balancer ; only the external balance 400 crank based assembly uses a weighted balancer .(EXT balance at both ends )


Part # ?

 

I haven't ever seen a true internally balanced motor from GM; any flex plate from any motor has always had some sort of weights on it.

 

Google GM part #14085720 , 3991469 or 471598

True neutral balance wheels for 2 pce RMS SBC with no weights

 

Its a 1 piece rms, and the part description states "int/ext" balanced. 942-1-91100BIE
thats the part number. This kit comes with a flexplate but the other its dont come with a flexplate or balancer or anything. I know i can get a neutral weight balancer, but i need a flywheel of the correct balance. A 400 flywheel would be correct? or no because this is an aftermarket piece? Can i bring my flexplate to a shop and get a neutral flywheel balanced exactly like the flexplate?

 

Your 1 pce RMS crank only takes 1 pce RMS flywheel which has a balance weight on it.

A 400 flywheel will be wrong balance and even if it was correct , it would not bolt up to your 1 pce crank


Whether your assembly is balanced to stock factory balance ( in which case you can use any off the shelf factory style flywheel ) or has been custom balanced is a different story.
You buy the correct 1 pce RMS flywheel , like one of these ( has to be 153 tooth to suit your T5 )
http://www.summitracing.com/search/p...tity/153-tooth

and take it and the flexplate to shop so they can compare the balance

Incorrect naming by the maker which leads to the INT/EXT balance confustion.
Thje 1 pce RMS Flexplate is externally WEIGHTED ; not externally balanced

 

Got it. So the easiest thing to go is get a flywheel, bring it to my machinist and have him compare the balances. If they are different then he can weight the flywheel the same as the flexplate and stick with a stock neutral balancer.

 

As I noted , only a 400 based "383 " crank has a weighted balancer ; all other SBC balancers are neutral , regardless what the rear crank arrangement is