Crankshaft worth saving??
10-27-2016, 08:51 PM
#5
I can see it looks like it put some heat into when it spun the bearing.
It might have to go .020 or more to clean up. And if its not straight now, It will deform again under heavy load. If they're not straight to start with, I trash them right away.
I would start with a known good crank and machine as needed.
The only one I have ever saved like that and ran was a 4G63T crank and there factory forged. If they weren't so hard to find and expensive, I would have grabbed another. I sent it out after machining to have it ION nitrated to bring the surface hardness back and strengthen it. It was still cheaper than a used crank shaft core...
Oh and the Pontiac 400 and 455 Cranks because the over sea's forged castings were crap at the time.
10-27-2016, 08:51 PM
#6
It's hard to explain the value of a good crank grinder. I've had the fortune of knowing one here in SE Wisconsin who just retired after 55 years. He has made plenty of cast GM rolled fillet cranks of mine look like race quality artwork after a ten/ten grind. His attention to detail with dressing the stone and his patience were second to none. These cranks have also survived some insane abuse as well. I wouldn't hesitate to run that if you know someone "good"
10-27-2016, 10:33 PM
#7
Then I definitely would not use it.
I can see it looks like it put some heat into when it spun the bearing.
It might have to go .020 or more to clean up. And if its not straight now, It will deform again under heavy load. If they're not straight to start with, I trash them right away.
I would start with a known good crank and machine as needed.
The only one I have ever saved like that and ran was a 4G63T crank and there factory forged. If they weren't so hard to find and expensive, I would have grabbed another. I sent it out after machining to have it ION nitrated to bring the surface hardness back and strengthen it. It was still cheaper than a used crank shaft core...
Oh and the Pontiac 400 and 455 Cranks because the over sea's forged castings were crap at the time.
I can see it looks like it put some heat into when it spun the bearing.
It might have to go .020 or more to clean up. And if its not straight now, It will deform again under heavy load. If they're not straight to start with, I trash them right away.
I would start with a known good crank and machine as needed.
The only one I have ever saved like that and ran was a 4G63T crank and there factory forged. If they weren't so hard to find and expensive, I would have grabbed another. I sent it out after machining to have it ION nitrated to bring the surface hardness back and strengthen it. It was still cheaper than a used crank shaft core...
Oh and the Pontiac 400 and 455 Cranks because the over sea's forged castings were crap at the time.
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10-27-2016, 10:42 PM
#8
We have a few of those here as well. But with the availability of these particular cranks, it's typically easier to get another one.
I have had people literally give them away as well as I know of others that have thrown them away.
I guess if it's cheap enough to machine and its straight before grinding, Go for it. But I would recommend sending it out for heat treating of some sort.
I have had people literally give them away as well as I know of others that have thrown them away.
I guess if it's cheap enough to machine and its straight before grinding, Go for it. But I would recommend sending it out for heat treating of some sort.
10-27-2016, 10:55 PM
#12
All the mains on the block look just fine but as far as I can tell nothing spun. All the bearings in the bottom end were destroyed. I had to replace the #2 main cap on it cause there were 2 small cracks on the bearing surface. Block was okay just need a line bore/hone