"Help" With a Spun LS1 ATI Harmonic Balancer
09-16-2010 | 10:30 PM
#1
"Help" With a Spun LS1 ATI Harmonic Balancer Ok guys, I really need some help here!
I have a 1998 Pontiac Trans Am with 65,000 miles on it and the LS1 motor. I put the vortech supercharger on it in 2005 (5 years ago). About 20,000 miles ago.
My wife was driving it and it threw all the belts. I thought it was just a bad belt that got in the way of the other belts. It was not.
When I got the stuff apart, the ATI harmonic balancer was sitting on the crank totally loose and with a very loose balancer bolt!
I took off the balancer and measured the crank snout that the balancer slips on too. The Crank snout is tapered from all of the spinning! It had to be doing a ton of spinning over the time.
Basically here are the measurements of the crankshaft snout now: Far back of the crank is 1.479 for only about a 1/4 inch forward. The rest of the crank forward (middle of crank snout) is about 1.465, the last 3/8 inch of the crank forward is well rounded and is at 1.436. I was told by ATI that they make their ATI damper hubs for the stock crankshaft snout size of 1.4815.
So there is about .047 thousandths difference from the back of the crank snout to the front of the crank snout! It is tapered larger in the back to smaller in front. So here is the big question guys, what can I do to not take the engine out and put a new crank in and get this current situation to work with a new ATI hub???? ATI will only make a custom hub size in ONE size, not in a taper of course.
Do you guys think that I can double pin the crank with the ATI kit and put a double key way ATI hub on it; then use metal epoxy weld like JB weld or permatex to take up the other tolerance? Once the balancer hub is in straight and laying against the back of the crank/oil pump put an additional 4 pins 1/4 inch size, drilled straight into the crank and ATI hub using the A&A kit to take up tolerance and prevent spinning? Do you think this would work? What are my options guys?
Please help, it's a sickening feeling. I never knew back in 2005 of the LS1 damper spinning problem or I would of pinned it then and the Vortech kit never said to. Again please help and honest opinions please. I don't want to have to spend all of the money of pulling the engine out and rebuild.
Thank you for your time.
I have a 1998 Pontiac Trans Am with 65,000 miles on it and the LS1 motor. I put the vortech supercharger on it in 2005 (5 years ago). About 20,000 miles ago.
My wife was driving it and it threw all the belts. I thought it was just a bad belt that got in the way of the other belts. It was not.
When I got the stuff apart, the ATI harmonic balancer was sitting on the crank totally loose and with a very loose balancer bolt!
I took off the balancer and measured the crank snout that the balancer slips on too. The Crank snout is tapered from all of the spinning! It had to be doing a ton of spinning over the time.
Basically here are the measurements of the crankshaft snout now: Far back of the crank is 1.479 for only about a 1/4 inch forward. The rest of the crank forward (middle of crank snout) is about 1.465, the last 3/8 inch of the crank forward is well rounded and is at 1.436. I was told by ATI that they make their ATI damper hubs for the stock crankshaft snout size of 1.4815.
So there is about .047 thousandths difference from the back of the crank snout to the front of the crank snout! It is tapered larger in the back to smaller in front. So here is the big question guys, what can I do to not take the engine out and put a new crank in and get this current situation to work with a new ATI hub???? ATI will only make a custom hub size in ONE size, not in a taper of course.
Do you guys think that I can double pin the crank with the ATI kit and put a double key way ATI hub on it; then use metal epoxy weld like JB weld or permatex to take up the other tolerance? Once the balancer hub is in straight and laying against the back of the crank/oil pump put an additional 4 pins 1/4 inch size, drilled straight into the crank and ATI hub using the A&A kit to take up tolerance and prevent spinning? Do you think this would work? What are my options guys?
Please help, it's a sickening feeling. I never knew back in 2005 of the LS1 damper spinning problem or I would of pinned it then and the Vortech kit never said to. Again please help and honest opinions please. I don't want to have to spend all of the money of pulling the engine out and rebuild.
Thank you for your time.
09-16-2010 | 10:51 PM
#2
Bub,
I think you're screwed, pinning it now is not the answer. You might keep it from spinning, but you'll never get the balancer to stay centered. Especially under the combined load of an accy drive and the supercharger...
I think you're screwed, pinning it now is not the answer. You might keep it from spinning, but you'll never get the balancer to stay centered. Especially under the combined load of an accy drive and the supercharger...
09-17-2010 | 05:57 AM
#3
Unfortunately I think you are looking are a crank replacement. Gap fillers and such could cause even more problems and further damage. Also, with the damper that loose you have to wonder about the condition of your bearings and other internal parts.
