Motorhead-47

I'm considering swapping to a ZR1 cam in my 09' LS3. The harmonic balancer is already pinned from my supercharger install. My concern is how to get the balancer aligned to the crank as it comes back together to be able to use the existing crank pin location. I've seen guys who just repinned the crank elsewhere to avoid the issue. I'd rather not do this. Anyone have tips on getting things aligned to avoid drilling a second hole? Being off even a tiny bit means the pin won't go back in.

carlrx7

i had the same issue when i decided to put in a blower cam after the supercharger install.

the pin was stuck in the crank, so I ended up putting the pulley in the oven @ about 250 degrees for an hours, grabbed some mittens and put in on as fast as i could. slid right over the pin and then i just used my old crank bolt to suck it down. Im getting ready to do it again pretty soon.

-Carl

Motorhead-47

You must have created a groove the length of the balancer when you originally pulled it off with the pin stuck in the crank. When I visualize this in my head I know that the original pin is only 1/2" long so the balancer side keyway only extends about 1/2" deep in what is probably a 1 1/2" or longer balancer hub. If the keyway in the balancer was the full length of the hub then it would be a no-brainer to get things aligned but I think I'll have over an inch of no keyway before I get the balancer on far enough to find out whether I'm aligned or not. Good idea on heating the balancer to allow it to expand. I used that technique to rebuild a P-Car 911 transmission that was supposed to take thousands of dollars worth of specialized puller/installer tools.


Anyone else out there have thoughts on this?

breecher_7

forged crank and new balancer?

old motorhead

I just eye balled it and got lucky....but the motor was on an engine stand (Walmart 2.5 reading glasses recommended). I can see "issues" with what you're trying to do with the motor still in a vette. Give it a go and see. If you can tell it's not likely to happen for you, drill it again 180 degrees away from original. I can't imagine that being a problem....other than a PITA

Motorhead-47

That would work but kinda radical for a $125 cam swap!

Ragtop 99

true, but that help justify doing a stroker crank and getting more cubes out of the deal.

breecher_7

Sure, but think of the possibilites with a forged bottom end!

Oh wait, i just remembered what kind of blower is on that car...

Nevermind, no reason to waste your money!

Yeah, its a cheap shot........

carlrx7

Maybe the pin was stuck in the pulley not the crank,, can't remember.. hmm I did it all in one try though.

ITSGRAND

I've had this concern many times myself and for that reason I never drilled my LS2 with the supercharger. I got the kit, but when i saw how to do it I asked the same question that you are asking now.

My suggestion would be to just do it by sight and pray that you get it ligned up.

OR, over dill the whole combo and hope that it doesn't get weak. Reinstall it with a longer pin and some sealer so oil doesn't leak forward.

wallyj

I wonder if the balancer could be drilled the rest of the way through. Then you could use a pin or drill bit as a guide.
Just a thought

Motorhead-47

If I had an old crank to use as a fixture that is exactly what I'd do....drill the balancer keyway thru to the other end.

It is starting to sound like I need to pre-heat CINC house's oven to 300 or so and cross my fingers

ITSGRAND

with the correct diameter betal burr, I'd bet that you could grind a straight strip on the inside of that balancer.

My question is, "what is that doing to the strength and balance of the balancer versus making a void and filling that void with a pin?"

SpinMonster

As you pull the balancer, the balancer pulls the pin forward with it. The pin always comes off on the balancer.

When removing, put a black marker mark on the 6 oclock position of the balancer and crank. Before you start tightening down, peek in the front to verify where the holes are. I've never had it not go back on right. Have the pin on the bottom so its easier to see when standing over it.

Motorhead-47

Thanks. Good to have practical experience info from a guy who may have done one or two.