Gravity bends a crank?

Bill, I think you're right. But instead of slowing down to look at the accident, try speeding up. Einstein observed that light and objects appear to bend at great speed, so if you speed by any crankshaft lying on a floor and blink fast enough it will appear bent. Einsteins theory of...
 
Six pages of opinion , but no facts. Do they bind or do we just think they bind. How much ?? If in doubt ,just stand them on end and be done..
 
dude, If you stand them on end, almost all the weight is pushing down on that last crank throw, right? And there's no support at the centerline of the crank, right? So eventually the crank will bend and maybe topple over, even! Whereas, if the crank is lying on the floor it is being supported at least in three or four places, thus spreading the weight out instead of all being focused at one point if it were standing on end!
 
'Resistance is futile' , In '95 Western Oregon had a 5.6 earthquake and I could hear my merc cranks falling over in the shop! Ring, ding, and clank! The one that has since been checked was badly cracked. Later Newc
 
rheltzel said:
See what can happen? Molly would have laid 'em all flat. Every last one of 'em.
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Hey rheltzel, does she still live in sac? What a gal! Wouldn't mind seein her again.......I'm not far away......sigh....laid my crank flat many a time.....sigh....
 
Lincoln said:
My previous employer, who manufactured medium-to-large industrial stationary type engines (up to 30,000 horsepower), had a policy to always store their crankshafts vertically as lying them down would "permanently" distort the throws even with the main bearing surfaces supported properly. So they were stored vertically with the flange end supporting it...
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How were the counterweights and journals supported when stored in the vertical orientation?

Without additional support the counterweights and journals will still have a bending moment imparted upon them when stored vertically. This would have a cumulative effect as you move down the crankshaft towards the ground (assuming they were stored sitting on a surface instead of hanging).
 
Also...if this IS a problem...what is the time frame? How long between laying down a crank and measurable bending? If the time is relatively short...
lay 3 carnks into a spare block, rotate'em against an indicator. If straight. leave one in the block, lay one flat, stand one on end. Re-indicate at given time...
The belief in bending seems to come largely from machine shops, where i would assume cranks don't hang around long before going to a home. In our cases, I'm sure some of us have cranks that have been in one place for multiple decades.
Science needs to know...
 
rowens55 said:
Hey rheltzel, does she still live in sac? What a gal! Wouldn't mind seein her again.......I'm not far away......sigh....laid my crank flat many a time.....sigh....
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Sadly, she is not in Sacramento. After years of working in the Rouge Plant cafeteria and suffering through too many harsh Dearborn winters, Molly moved to Florida and opened a profitable crank straightening business there for those whose cranks were bent from being laid and who were in need of re-straightening. It is said that Molly could straighten old bent cranks when no one else could. She was, as you can imagine, a legend in her time.
 
It has been verified that a sheet of window glass standing vertically will eventually become thicker at the bottom than at the top. It sort of slides down as if like honey. I suppose this could happen to a vertically standing crank if left that way for a long period of time. So make sure when storing you alternate positions from time to time. Need data to know the proper timing on this theory. Has anybody on the BARN done the research ? ;)
 
Okay, I've solved the problem....Grease, we fill a pool with heavy grease and lay the crank in the grease and as the crank slowly sinks to the bottom over the years ,the grease evenly supports the crank from all sides and prevents rust. Problem solved.
 
Fibber Mcgee said:
Okay, I've solved the problem....Grease, we fill a pool with heavy grease and lay the crank in the grease and as the crank slowly sinks to the bottom over the years ,the grease evenly supports the crank from all sides and prevents rust. Problem solved.
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Nothing new there. That's how Molly would start her day off with a bang.
 
Fibber you best make sure it is corn head grease. Molly probably used it also. Corn head that is.
 
There was a company in South Gate called Chrome Crankshaft that polished cranks and you could get your bumpsticks done as well.
Bruce
 
Roger/Sacramento said:
It has been verified that a sheet of window glass standing vertically will eventually become thicker at the bottom than at the top. It sort of slides down as if like honey. I suppose this could happen to a vertically standing crank if left that way for a long period of time. So make sure when storing you alternate positions from time to time. Need data to know the proper timing on this theory. Has anybody on the BARN done the research ? ;)
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Roger, that was believed to be true for many years, until they found 600-yr-old glass that was thicker at the top. It turns out it was just a result of the process used to make it. If you can believe it, they used to blow glass in cylinders, cut it, and flatten it out.
 
Glass don't move, it stays the shape it was made. The belief was based on the thick bottom of a window. This was just the way it was put in in the first place.
And if JWL has stated that flathead cranks stored anyway for unknown time, show no evidence of "bending" in storage, when put on a crank grinder, then the question has been answered.
They don't bend.
Martin.
 
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