DoesSpeedTurnUon

iTrader: (17)

I know some of the older chevys were balanced on the flywheel. Does anyone know if the motor can safely run with out a flywheel on it?

TIA!

MrDude_1

iTrader: (4)

you need the bolts in unless you want oil blowing everywhere.....

but the flywheel itself is neutral balanced.

DoesSpeedTurnUon

iTrader: (17)

hmm, thats good to know, thanks!

JPH

iTrader: (2)

older chevy small blocks 283-350= neutral balance, 400=external balance.
i would not run a motor without a flywheel, good luck getting it started without one.

NoGamesLS1

iTrader: (16)

How do you plan on starting the motor?

DoesSpeedTurnUon

iTrader: (17)

lol... it has one of those cranks on the front like a model A. haha

good point.

NoGamesLS1

iTrader: (16)

haha thats what I figured. That was a rare option huh

MrDude_1

iTrader: (4)

i was wondering the same thing myself.... but i figured he had some other idea... guess not.

vettenuts

iTrader: (4)

The flywheel is used as the final balance point on the assembly line. Some get by with zero balance, some do not. That's why when you change the clutch you have to match balance the new setup to the old or you will get vibration. Zero balancing doesn't guarantee no vibration. Proceed with caution.

Cobra4B

iTrader: (9)

^ Correct... I learned the very hard and very expensive way. Turns out my stocker was 8 grams off... now that my new one is all is well.

DoesSpeedTurnUon

iTrader: (17)

I mainly needed to know because i'm selling the LS1 and the T56 seperate, but i want the buyer of the LS1 to be able to hear it before i pull it out, and see the oil pressure and know that it runs good. But the T56 is pretty much sold, i'm bout to pull it out, just wanted to make sure it'd be ok to run the motor basially with out the transmission on. I guess i'll have to keep the flywheel.

Beast96Z

iTrader: (21)

Hmm, what do people with new motors that have never had a flywheel do? I'm sure a aftermarket short block is balanced a little better than a stocker, so I would assume that a neutral balanced flywheel is the way to go?

gun5l1ng3r

Why are these things not mentioned when buying clutch parts!!
Damn, I put a clutch in about 10 months ago and didn't balance anything. Just picked up the Zo6 clutch from the GM dealer and threw it in.

What are the consequences of not match balancing the new clutch to the old clutch?

vettenuts

iTrader: (4)

If it doesn't vibrate, nothing. I think most are zero balanced, but when the motors come off the line if the motor doesn't balance they add weights to the flywheel for correction. GM recommends moving the weights from the old to the new flywheel, and the only way they could recommend this is if the clutch/flywheel is zero balanced to start with.

I am wrestling with this right now, not sure who to go to for balancing.

MrDude_1

iTrader: (4)

it should be noted.....

1. the vettes and the fbodys have the exact same engine.

2. the vettes are the only ones who received this finial "extra finish" balance....

3. fbodies dont have a normal problem with unbalanced motors.



the reason you dont see it mentioned is because its a very fine, small detail they did for the vette... but its not really required.
just adding a cam, or even poly mounts, adds more vibration to the car then this...

Cobra4B

iTrader: (9)

^ Huh? Aren't the motors built on the same line? I know for a fact my stock flywheel had 2 balance weights in the back... and when I put my new zero balanced Luk Stage II in the car had a new vibration it didn't have before.

Then... I had it matched to my stock stuff, and purposly off-balanced to the same 8 grams that the stocker spun to. Now my car is fine.

Trust me.. I researched this ad nauseum... called all the major tuners, spoke w/a GM high-level rep. Reviewed multiple years of service manuals etc etc.

Some people get away w/ it... some don't.

MrDude_1

iTrader: (4)

the motors are built on the same line.... to a point.
after that, they split.. some get fbody stuff put on (pickup, pan, crank pulley..) some get Ybody stuff..... they're already split by the time they're bolting on the flywheel/flexplate.... and the Fbodies dont get a special final balance.

Cobra4B

iTrader: (9)

^ Why not? The pistons/rods/crank come from the same parts and same assembly.

MrDude_1

iTrader: (4)

because they're all within regular production tolerances... tolerances that are MUCH MUCH tighter then what GM used to pass with genI SBCs for decades....

so GM decided it wasnt necessary.

now the Corvette, being the flagship special model that it is to GM, got the extra step.... keep in mind, GM can also charge more for the corvette, and that allows them to do this easier then for other cars... it all comes down to the beancounters.




in anycase, my point was, we dont have excessive problems with the fbodies, and they do have the same internals.

Cobra4B

iTrader: (9)

^ Interesting.