C.A.T. Crankshaft ?

[hemi8]

I've done a few searches and can't find much info. Did you build your engine with a CAT crank? If so, what clearences did you see on the rods and mains? Does any work need to be done to the crank or is it ready to go from CAT? This crank is internally balanced, does this cause us trouble or is this no big deal for the machine shop? If we use a different SFI balancer, how do we get the signal to the crank sensor, do these balancers come with a factory interupter ring?
Mike
86 GN
Awaiting the release of Champion's Stage 2 block.

 

[S2V6RACER]

You can get a BHJ balancer that is set up for internal balance, or some have modified the stock balancer this way. Let your engine builder know you need a neutral balance done. He will know what you are talking about.

 

[Jeff Rand]

I also have the same questions regarding the crank. I am planning on doing a 109 engine build for a friend using a stroker kit with an internal balance. When I get the crank, I will take it to a specialist and have it checked out. I heard it is a roll of the dice on getting a good one. So it's buyer beware.
Jeff

 

[Under Pressure]

I've done a few searches and can't find much info. Did you build your engine with a CAT crank? If so, what clearences did you see on the rods and mains? Does any work need to be done to the crank or is it ready to go from CAT? This crank is internally balanced, does this cause us trouble or is this no big deal for the machine shop? If we use a different SFI balancer, how do we get the signal to the crank sensor, do these balancers come with a factory interupter ring?
Mike
86 GN
Awaiting the release of Champion's Stage 2 block.

I have a cat in my 109.I went with .002 on the mains .I forgot the clearance on the rods .Its internally balanced i went with BHJ balancer(neutral balanced)with interuptor ring built in to it ,also JW flywheel (heavy, neutral balanced also)My crank had to 2 slugs of moly in it to get the balanced out right.BHJ was to tight of a fit i honed balancer so it wouldnt gall the snout of the crank ,also the wooddrift key was to large i had to rework that on a belt sander to insure a good fit. You running K1 rods?

 

[Nick Micale]

We have used CAT cranks, and have seen no problems. Some do require a little "clean up" work, but something a good machine shop would normally do anyway.

In our opinion, it is not feasable to try and make an internal balance crank [or the so-called stock balancer] into an external balance unit.

We had Eagle make us a run of external balanced forged cranks to fill this need.

 

[Jeff Rand]

We have used CAT cranks, and have seen no problems. Some do require a little "clean up" work, but something a good machine shop would normally do anyway.

In our opinion, it is not feasable to try and make an internal balance crank [or the so-called stock balancer] into an external balance unit.

We had Eagle make us a run of external balanced forged cranks to fill this need.

Nick,
Have you tried to zero balance the stock balancer? I know Reg West had his street car's balancer modified so he could use an internal balanced crank. The project I am working on will be a street car and we were planning on going with set up along with a JW flexplate.
Thanks,
Jeff

 

[Nick Micale]

Jeff, since the stock "balancer" is just a solid, cast iron hub, and NOT a real harmonic balancer, we would not modify one or use it in a performance application. Have seen too many of them go bad, even on stock builds.

The BHJ may be pricey, but it will provide the proper balance at RPM, dampen crankshaft and camshaft harmonics, and not fly apart at the wrong time.

 

[hemi8]

So is the Eagle crankshaft or the CAT crankshaft a better piece...........We need someone like Oliver to make a real nice crank for us. What kind of clearences are people seeing with the Eagle crank?
Mike

 

[1dmbth]

They do make real nice cranks if you want to pay $2600 for it

 

[49-blues]

Nick- are they making external cranks in the stroker configuration?

 

[Nick Micale]

Nick- are they making external cranks in the stroker configuration?

No.

Stock stroke only.

 

[Underboost]

Nick,
Have you tried to zero balance the stock balancer? I know Reg West had his street car's balancer modified so he could use an internal balanced crank. The project I am working on will be a street car and we were planning on going with set up along with a JW flexplate.
Thanks,
Jeff

I have just finished a CAT, JW, & BHJ setup. The crank was way off the BHJ had a lot of metal takin out and the JW had the stock weights removed and some added. All n all the motor is neutral now. $$$$ in machine work