Questionable Crankshaft Balancing.
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Teching In
Joined: Dec 2023
Posts: 14
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Questionable Crankshaft Balancing. I'm doing a mild build build on a gen 3 5.3l ls. As part of the build I replaced the pistons with forged summit pro ls pistons as the original pistons had some scoring on the skirts and I did not feel comfortable reusing them. Since the pistons were replaced I had the crankshaft balanced at a local shop. When I received the crank back I was told the balance in the rear was way out and the front was fairly close. To correct the imbalance they drilled holes vertically into the rear counterbalance and pressed in the Mallory metal, then welded the top of the hole. Based off of some other research I've done, this is not ideal as the centrifugal force could push the metal or pieces of weld out of the crank and cause catastrophic failure. I noticed as well that they drilled a fairly large hole and when they pressed the metal in it somewhat pushed the wall of the counterbalace outwards. They also ground the rear crank throw near the 7nd8 rod journal to remove weight from that side of the crank.
This engine will only be revving up to 6500, should I worry about the pressed metal plugs or welds failing and causeing major damage? Is the slightly bulged counterbalance wall or ground 7and8 crank throw something to be worried about as well?
This engine will only be revving up to 6500, should I worry about the pressed metal plugs or welds failing and causeing major damage? Is the slightly bulged counterbalance wall or ground 7and8 crank throw something to be worried about as well?
I think Che70velle also wanted to see the metal slugs/holes used for balancing. I will say I have never seen a crank that had the counterweights ground off with a belt sander or body grinder. I hope they knew what they were doing.....
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Verdad Gallardo The reluctor has a .01 runout window. If it’s got hot and warped, the CPS can’t read it properly and it will never start. And if it does start, it will run terrible. The reluctor has to be straight. You can check it when your mocking up the crank to check bearing clearance. Set up a magnetic base dial indicator on the wheel itself and turn the crank slowly. Fingers crossed for you.
Thread Starter
Teching In
Joined: Dec 2023
Posts: 14
Likes: 5
The reluctor has a .01 runout window. If it’s got hot and warped, the CPS can’t read it properly and it will never start. And if it does start, it will run terrible. The reluctor has to be straight. You can check it when your mocking up the crank to check bearing clearance. Set up a magnetic base dial indicator on the wheel itself and turn the crank slowly. Fingers crossed for you.
I agree with others. It looks like a real cobble job. If it was me, I'd also check the crankshaft itself for runout. Personally, I've seen some real hack jobs in my lifetime, but never anything like that on a crank. Looks like somebody dropped it on a belt sander. But as Scott said, if everything checks out, and it's balanced OK, I'd send it. Nobody has to know, though something like that would bother me, just because I know it's there, lol....
Thread Starter
Teching In
Joined: Dec 2023
Posts: 14
Likes: 5
I agree with others. It looks like a real cobble job. If it was me, I'd also check the crankshaft itself for runout. Personally, I've seen some real hack jobs in my lifetime, but never anything like that on a crank. Looks like somebody dropped it on a belt sander. But as Scott said, if everything checks out, and it's balanced OK, I'd send it. Nobody has to know, though something like that would bother me, just because I know it's there, lol....
If it was my crank, considering that grind mark, I'd check prices at a local crank/machine shop to just check the balance job. My .02, and good luck.....
I couldn't sleep at night with that in my engine, but I hate to be that guy that oils down the track!.. If their workmanship is that shoddy how good can the guy doing it be at balancing an engine.. if sending that out the door was good enough what were his thoughts while balancing?