Are LT1's internally ballanced?
 

just what the tittle says. Don't laugh at me I'm new to this motor.
Thanks

The crank is balanced for the lightweight hypereutectic pistons, but the entire rotating assembly itself is externally counter-balanced at the flywheel. Front hub/dampner is neutrally balanced.

So if I have I zero balance flywheel I have to get it wieghted to match the prior one?

What brand flywheel are you running?

Yes, it is recommended to have the new parts matched to the imbalance of the factory pieces, in hopes of lessening the chance of a vibration issue (not only uncomfortable, but can cause premature main bearing wear/damage). The trick is finding a machine shop that can do this for you.

Some people have gotten lucky without balancing, which may be in-part due to the loose tolerances of stock specifications. You'll find a small weight cast into the back of the stock flywheel -- the same flywheel that is used in all 93-97 LT1's...

I am putting in a spec billet flywheel

Not to get off subject :offtopic:
but how do you like the Delteq system, and how long have you had it.
Brentt
Oh, and what took you so long to join LS1tech?
Welcome to the site :drive:

I gave him a little nudge the other day to finally join here right Alex:D

I'm pretty confused on this whole internal/external balance thing now. I thought that I understood, but I think I am more confused now. I purchased a new Cola 3.50 inch stroke 4340 forged steel crank for SBC 1 piece rear seal. It is a 350 main and is going to be used in a forced induction buildup for my LT1. It does not state whether or not it is internal or external balance and I thought that all 1 piece rear seal cranks were internal. I am going to use an ATI Super Damper and a steel flywheel Street Twin clutch assembly. So, is this going to be an internal or external balance or, like I have heard before, can you do either type of balance and which is better? I have heard that the internal is more expensive though.

if you are going to be really spinning your car up then have everything sent to the balancer for balancing. thats the rotating assembly and botht he flywheel and hub/balancer. or if you just want it balanced send the rotating assembly and have it balanced. then you should be able to use a neutral balance flywheel too. at least i think thats right:confused:

Ok, I am just getting the parts together and I am going to have the long block professionally built. I was planning on sending the ATI Super Damper and the Street twin to have everything balanced when it is built. I probably won't be spinning it past about 6,800, but I want the thing built right!

The stock motor is counterbalanced at the flywheel.

If you are going with a rebuild, have it neutrally balanced and get a neutrally balanced flywheel and an SFI crank.

You can balance it externally which means the machine shop should take your front damper, and your flywheel and balance it all at the flywheel.

You can do internally which means they just need the crank/rods/pistons. Its then up to you do make sure your flywheel is also zero balanced. This way they may need to add heavy metal to your crank which is $$$, but its the better way to do things.

Hey Altjar... you the same one from the z28board?? Anyway so only the LT1's are internally balanced???? I'm lost.

Ya same atljar from cz28.

Stock lt1s run a nuetral balance balancer and an externally balanced flexplate/flywheel.

If you build a new engine you can go either way.

Sounds like I'm in trouble? I have a stock bottom end with a yank 3600. Gave it the gas the other day and it seems the weight attached to the flexplate sheared off, ending up in my dustpan. I'm getting a very noticeable vibration now. Scared to drive it bad.... I cannot just throw a new TCI flexplate on there can I?

Depends on the condition of the crank whether or not it needs metal added for an internal balance. It is indeed far better to get the rotating assy. internally balanced in case a flywheel/flexplate needs to be replaced.

I'd be more interested in wanting to know how a counterweight sheered off?

I never knew that.. But, good to know..

We sometimes refer to them as hybrids, just like the L98s. Neutral at the damper/balancer but counter-weighted at the flex-plate/flywheel.

". . . it seems the weight attached to the flexplate sheared off . . .", did it?

Jake

I always get everyone of my Engines balanced.

That's kind of funny the way that was said. :lol: