Bryant crankshaft. likely been dropped. need advice.

[D.Galea]

Like the title say I bought a bryant crank off ebay. It's got ford 302 mains and 1.850 main journals. It was stated that its new and that it came from yates shop. I already have the rods and an r452 block so I want to make use of it.

It arrived in the original bryant cardboard box with the roush yates address still on the box.. BUT one of the counterweights was hanging out of the bottom of box when it arrived. I told the seller to package it properly as I live outside of the US. I guess he did the best he could with some old rags and cardboard as padding.

1 how can I tell if its damaged or bent? magnaflux it and measure run out? can i measure run out accurately by putting it in the block and using a dial indicator? or do I take too a machine shop..

2 Any way to verify that it's really new? Is measuring the journals the best indicator of milage/use?

[rebelrouser]

Measure the rods and mains. Take your block and install just the first and last main bearing, set the crank in the block, and put a dial indicator on the center main journal, rotate the crank, if there is no run out, and the journals measure to size I would use it. Some of the machinists might have a better method, but being an old mechanic, this is how I check an unknown crank, never burnt me yet, knock on wood.

[BillK]

I would have to agree with RR. Check it real good for sizes and then stick it in a block and see how much runout there is. I would check the center main and also the snout. If it is ok then run it.

[amcenthusiast]

Fear makes the wolf seem bigger...

I tend to consider the damage to the other object that the crank hit when it was dropped, not the crank (!)

That Bryant crank is made using superior techniques and superior metal which makes it somewhat invincible, like an industrial rock drilling tool.

It's made to absorb incredible impact -it'll flex and return to it's original shape like a spring. (it is a spring, but super high rate)

[dannobee]

And if you've ever witnessed a crankshaft being "straightened," you wouldn't be fearing anything UPS could do.

[piston guy]

+1 it's almost "stone age" looking when it's done. Still best to check it for runout.

[1972ho]

Even if it’s bent more .008 it can still be straightened all they do is take a big steel type chisel with a radius on the end and a big hammer and pound it and it will straighten itself I forgot how Castillo told me how it happens but is happens.

[rebelrouser]

And if you've ever witnessed a crankshaft being "straightened," you wouldn't be fearing anything UPS could do.

I had a guy that burnt a rod bearing, and it warped the crankshaft, when the machine shop straightened it, I was there, you are right, he basically beat it with a sledge until it was true again. Engine is still running, 5 years later so it must be OK.

[D.Galea]

I will definitely check it for any run out. Thanks for all the advice at least now I know what my options are.

[modok]

Check runout.
If it's not bent, it's not cracked.

Things do not crack and then return to exactly the same shape as before. Unless it was cracked all along.

[stealth]

They are ALL bent (warped) after heat treat... . every one is straightened at supplier...

[Monzsta]

Even if it’s bent more .008 it can still be straightened all they do is take a big steel type chisel with a radius on the end and a big hammer and pound it and it will straighten itself I forgot how Castillo told me how it happens but is happens.

You grind a broad radius that will get into the filet. Then to straighten the crank you work the inside radiuses of the crank throws on the low side. This compresses the metal and raises the crank toward the side you're actually hitting. Once you get the crankshaft straight the rods are cut and if done properly any impact marks will come out in the grind. Then the mains are cut.

[Mark O'Neal]

And if you've ever witnessed a crankshaft being "straightened," you wouldn't be fearing anything UPS could do.

LOL...I had them break the nose off a Cola crank a lot of years ago. No idea how they managed it.

[Sparksalot]

If the typical straightening methods are used on a crank there is no way that peening broke off the the nose of a crank without underlying issues. Cracks? Bad material? Could be a number of problems. Be happy it didn't happen in a running engine.

It has for me and it wasn't fun.

[Monzsta]

The shop I was in had a crankshaft press. Sliding V blocs on a beam and a big hook that pulled down. I didn't like it because as mentioned above, a crankshaft is a spring, and to get a bend to set you had to go waaay past your bend measurement in the opposite direction. You were forcing the crankshaft to the yield point. I had far better results peening the radiuses and none of the heart attack inducing "TING"s when pressing a crankshaft.