A crankshaft for 68.00 It's used, but looks ok from the picture. However I won't know more until I get it home. Just wanted to have one extra just in case....
William;
Have it magnafluxed(sp) to be sure.
Boy, that was anticlimactic.
Great story though.
Will:
Hang the crank by a cord then lightly tap with a metal bar.
If it rings, should be ok
If it thuds, it's a doorstop.
Old wives' tale ????
I have had a number of them that ring clear as a bell and had multiple cracks. Old wives tale, worthless info for sure. I would not pay money for another T crank without it being magnufluxed first.
As I've said before, the ring test should be used to fail a crank, not pass one. If it rings, get it magnafluxed. If it doesn't, don't bother because it is most definitely garbage.
well, you pretty much can't have one from an auction magnifluxed first before buying, now can you?
Back when I was actively looking for crank cores at meets or auctions I had my swap meet wagon with a small Honda generator, my magna flux unit, and micrometer. If a crank passed the mike test, I'd fire up the generator and mag it. If it passed, I would buy it. About one out of seven cranks is a candidate for regrind, in my experience, at least at that time about ten years back. Grindable cranks are more scarce now. I gave up the hunt for several reasons. It got harder to find good ones. Second, it would invariably invite a crowd when I would start the generator and start checking cranks. When I found the inevitable cracks, it would often tick the vendor off, understandably, especially if it was a nice looking crank with a steep price. Anyway, about that time Scat and other new cranks came out and a lot of my customers jumped on that bandwagon. I still have a bunch of reground stock cranks and no longer actively seek them. About the ring test: if a crank does not ring, scrap it. If it does it may be cracked. Have it magna fluxed.
Erik
Ok, so I bought a crank from a seller. The crank, if I remember the story right, came from a running engine that was disassembled and parted out.
I know a standard crank's journals are 1.248
Here's the measurements I THINK I might have:
Main # 1: 1.247
rod # 1: 1.243-1.247
rod # 2: 1.246
Main # 2: 1.232-1.235
rod # 3: 1.246
rod # 4: 1.246
Main # 3: 1.247-1.248
Do these measurements tell anything that I might be missing? I feel I should be concerned with Main # 2.
The measurements fluctuate a half a thou here and there. Doesn't appear to be any abnormal scratches or pitting of the journals.
Thoughts?
The journals wears out of round. You can't adjust the babbitt for an out of round journal that differs several thousands, so the crank has to be reground and the babbitt repoured and align bored undersize. Main #2 may clean up at 0.020 undersize if you're lucky. But before spending money on grinding you should spend a smaller amount magnafluxing the crank. (A lot of flexing in the #2 main may have taken most of the fatigue life out of that crank?)
The fact that a machine shop has a crank grinding machine doesn't mean they know how to align and grind a Model T crank.. Be careful and read some of the threads on crank grinding:
http://www.mtfca.com/discus/messages/80257/84487.html?1236666373
http://www.mtfca.com/discus/messages/29/24337.html
I have some remanufactured cranks, built back to standard. Email me if you are interested. Dan
a crank shaft being installed on a rebuild should be magnafluxed, if you want to break a crank on a rebuild, INSTALL A Z CRANK, THEY ARE GUARANTEED TO BREAK!!!unless you are restoring a trailer queen, then you can use a cracked crank or a z crank. but NEVER USE A Z CRANK on a T driver