always faster

Well i ve bought a LT4 crate engin.I also bought the lt4 intake to fit on the lt4 heads(basic need).

All i need to do right now is to install all my accessory(alt,waterpump,opti,hub,balancer,flywheel ... you get the point).

Since this is a new engin, can i install my stock lt1 harmonic balancer on it or do i need to have a zero balanced one or a special one for the lt4?

Same question with the flywheel?

Thanks

The Engineer

The front of LT1/4 cranks shafts are all internally balanced, therefore they use a harmonic “dampener” not a balancer. So, yes you can use your factory unit,

The rear of the crank is the real issue with a rebuild LT engine. The LT factory engines are always externally balanced and require flexplates, or flywheels with a counter weight (clocked in the correct location). However, most rebuilt LT stroker engines are internally balanced are require a flexplate, or flywheel “without” a counter balance weight.

Check with your engine builder to make sure which flexplate, or flywheel to use.

WD

http://www.cardomain.com/ride/2189634

always faster

So i just put my stock lt1 hub and my stock lt1"dampener" and i should be ok...right?

Its a factory engine from GM that PACE Performance sold me,so my best bet i think would be to call them and ask.

always faster

So i ve ask for the 2 questions to the shop and man they are really quick for helping(i like that)

Heres the email:

"Hello Eric,
I assume you are putting this in a Camaro or Firebird?
If so you will need to use the hub and balabcer from the LT1. The LT4 hub
and balancer will only work with Corvette brackets and accessories - the
spacing of where the belt grooves ends up is different.

This is an internally balanced engine that uses a counterweighted flywheel.
The reason for this is that when GM went from a 2 piece to a one piece crank
seal in the late 80's the bobweight that was previously on the older
crankshafts dissapeared, so they had to make up for it by weighting the
flywheel - this carried through to the LT1 and LT4.

You can use any 1986 and newer flywheel on this engine, but LT1 flywheels
are special for the clutch bolt pattern.

If you are putting this in a Camaro or Firebird, use your original LT1
flywheel. The LT4 Corvette used a dual mass fluid filled flywheel that is
crazy money. You original LT1 flywheel will work just fine."

So i guest i will just put back my stock lt1 hub and balancer and my stock lt1 flywheel on the new engine rand everything should be fine...right?

The Engineer

Yes us an F-Body hub and dampener, the F-Bodies have a different pulley spacing than a Vette.

Also, you use a stock LT flywheel, or flexplate with the counter-balance weight (clocked correctly) on the crank hub.

However, I have an issue with wording from your friend’s e-mail. If a crank-shaft is "internally balanced," it “does not” require a counter weight on the flywheel, or flexplate. Conversely, if a crank is "externally balanced," it “requires” the counter weight.

WD

always faster

So the hub and dampener is set.

Well stupid question ,how do correctly clock my LT flywheel on the crank hub?

Porbably a misprint

97 6SPEED Z

Always faster, "The Engineer" has given you some very sound advice here. Technically the guy at Pace Performance who answered your e-mail by saying that your new LT4 crate motor was "internally balanced" but needed an externally counterweighted flywheel ...... was wrong. If your motor was truly internally balanced, then both the dampner and flywheel you'd use would themselves be "neutrally" balanced. I know you're still worried about putting this engine together correctly but if you use your current LT1 F-Body dampner, hub and flywheel, you'll be just fine. You're actually misunderstanding the question about correctly "clocking" the flywheel counterweights, the counterweights are already attached to your old LT1 flywheel, and there is only one way the flywheel attaches to the crank. When you get to this step just slip the flywheel over the dowel pin on the end of the crank, and line up the six(6) bolt holes.

red94chicken

i have a real lt4 and they are balanced the same as an lt1.. you can use the stock flywheel.

The Engineer

The LT crank hub "should have" a roll-pin installed that correctly keys the flywheel, or flexplate to obtain the correct clocking of the counterweight. However, the roll-pin may not be installed in the hub (I've seen that before). Again, the counter-weight "must be" clocked in the correct position with an externally balanced engine.

WD

always faster

Well the truth is that i ve changed many many parts on this car but never take an lt1 apart So yeah i didnt understand the "clockin thing".Im pretty relief now that i know that there is only one way ton install the flywheel.

My 2 small problem are solved now because all the other parts should be simple installation.

Thank you all

Injuneer

You can't make a blanket statement like that about a rebuilt crate engine. Even the builder (Pace) doesn't seem clear on what is required. We may all think we know how they balanced it, but he has to be 100% certain.

The Engineer

One thing for sure, the engine will let you know if you get it wrong!

WD

http://www.cardomain.com/ride/2189634