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Crankshaft storage...


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So, I apparently have a problem. I've recently brought home my second orphan engine (it will go in a Willys pickup someday). So, I now have two engines with the crankshafts removed. I've always heard crankshafts and camshafts should be stored vertically. Any veracity to this, or is it just an old wifes tale?

Thanks!

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This is a fun thing to research, it’s been discussed on a lot of other forums.  The best comments?

 

Well, if the metal will bend laying on floor, then it will stretch if you hang it upright.  Wait long enough and you can use a 4 cylinder crank in a 6 cylinder engine.

 

Since metal deforms over time, make sure to keep the pistons in the cylinders, that keeps the cylinders round.

 

Now for real, the best explanation Found is that if you lay a crank down, and it’s left at a constant temperature with no fluctuations, it won’t deform.  It’s the heating and cooling of the metal in that situation that makes it deform ever so slightly, but thousandths of an inch are important in engine geometry.....

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33 minutes ago, trimacar said:

This is a fun thing to research, it’s been discussed on a lot of other forums.  The best comments?

 

Well, if the metal will bend laying on floor, then it will stretch if you hang it upright.  Wait long enough and you can use a 4 cylinder crank in a 6 cylinder engine.

 

Since metal deforms over time, make sure to keep the pistons in the cylinders, that keeps the cylinders round.

 

Now for real, the best explanation Found is that if you lay a crank down, and it’s left at a constant temperature with no fluctuations, it won’t deform.  It’s the heating and cooling of the metal in that situation that makes it deform ever so slightly, but thousandths of an inch are important in engine geometry.....

 

Excellent analysis. This old wives' tale is right up there with batteries on concrete. The best reason I've heard for hanging a crank as opposed to laying it down is that by hanging it, you're less likely to drop something on it and nick a journal.

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I have never heard of hanging them, only storing them vertically, usually sitting on the crank flange. Wouldn't that likely put less weight stress on it than laying it flat, just due to a reduction in leverage? I don't know, but it is an interesting point to consider.

 

I was unaware that the kind of temperature changes found in storage made such a difference.

 

Cast iron does move around when sitting. Anyone who doesn't believe cast iron moves should take a brand new brake rotor (or drum) that has been sitting in a stack and re-machine it. Despite the clearly visible machined surfaces, it won't be close to straight.

 

For long periods, I would rather store the crank in the block.

 

One more thing, Are forgings any more stable over time than cast iron?

 

 

 

 

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IMO, corrosion is the big problem to avoid.  On a "Chasing Classic Cars" episode a guy had a disassembled engine & put the crankshaft in a bucket of oil for many years to keep it from rusting.  It was pristine when removed from the bucket.

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I worked in an automotive machine shop when I was young that had a crankshaft grinder. We always stored crankshafts vertically on the flange. After they were ground they were lightly oiled, put in a plastic bag and tagged. Sometimes they would sit there for weeks or months before the customer would pick them up with no problem. That machine shop has been in business for over 50 years and they are still storing crankshafts vertically.

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48 minutes ago, Bloo said:

I have never heard of hanging them, only storing them vertically, usually sitting on the crank flange.

 

Invariably when I do that, they get knocked over.  Hanging eliminates that possibility.

Turns out, they sell crankshaft hanging racks for machine shops.

 

CH-2-double-crank-rack.jpg

 

And back to the OP's question, this one holds both cams and cranks.

 

CH-1-crank-rack.jpg

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If I may add.   I recently, about four years back, built a straight eight Buick engine. I bought a complete engine to build. However, it was from a Dynaflow car and the crank flange is a little different than a standard transmission flange.  The seller had a standard transmission crank, lying on the floor in a shed. Open to the elements.  For 17 years.  Shed did have a roof.   The machine shop, one that only does performance engines, cleaned it up and turned it after I had it blasted.  Never mentioned any problem.   Ten thousand miles or so and all is good.

 

  I wouldn't worry, Ken.  Whatever is most convenient for you.

 

Good luck

 

  Ben

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1 hour ago, Bloo said:

For long periods, I would rather store the crank in the block.

 

 

Me too! The first engine is just a hulk, with no main bearing caps. I'm honestly not sure why I still have it.

 

The second was fully disassembled by the previous owner, to "see how the engine works," and it will need to sit for several months before I take it to the machine shop.

Good points all, thanks, and especially about the corrosion.

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I've always stood them up and good ones oiled and bagged then tied to a post or shelve stantion. I still have rows of Model A and T cranks and cams in between my garage studs..Axles too..

 

Vertical keep them out of the way better.

Even laying down in a spot you think safe? ,stuff can get droped on them.

 It's to easy to not be mindfull and pile crap on top of stored crap on flat surfaces.

 

We've been in and out of many rebuilding shops and you never see any cranks stacked in storages.Any accumulations are stood up in rows.

 

Imagine single cranks beind shipped in pain heavy cardboard boxes.

Many I bought reground cranks  and cams too that were shipped as much as 3,000 miles to me. They all were still true.Even Model T ones.

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Standing seems to be the most popular.

I have heard that hanging is better (dont know why, but at least you wont be knocking it over).

Since I rarely practice what I preach mine are all laying on a deep shelf.

 

I see the same concerns for storing heads, standing could make for an accident, storing on a shelf is closer to how they live in service.

So I guess my extra crankshafts could be OK laying horizontal too.

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  This one came to us in 2004 from the spares stores of a nuke power plant in Japan.  They had standby generators of the same model as our mains and the factory in Wisconsin was quoting ~ six months to manufacture one.

  It probably was never stored vertically. These are  Colt-Pielstick model PC2 V-12 engines.

  This CS went into the starbord main engine through a opening cut in the aft of the #6 hold.

   I do realize the thread is referring to automotive crankshafts but I thought this might give some idea of the scale involved in other industries.

 

 thumbnail?appid=YMailNorrin

 

 

 

 

 

 

 

 

 

 

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The link is leading to Yahoo mail, so that is probably where the picture is.

 

If my guess is correct, only you can see the picture because only you are logged into your email. You will either need to either:

 

a) upload the picture to the forum, or

 

b) upload the picture to some hosting service (imgur.com is free), and paste the link in your post using the link tool at the top of the post editor (looks like a chain link).

 

.

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Years ago OSHA would come around to inspect engine rebuilding plants. They would fine the plants for each crankshaft they found standing on the floor. They considered the standing crankshafts safety hazards because they could tip over and hurt someone. Those racks were a way to comply with regulations.

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I have a tough time believing that the stress on a crankshaft from lying horizontal (due to its own weight) would have any measurable effect on the straightness/concentricity of the main bearing journals.  Think how many multiples of stress it is subjected to in operation (with no plastic (permanent) deformation if properly designed).  I'm too lazy to look it up but I'm sure creep properties of cast iron or steel at room temperature would far exceed the maximum stress from horizontal storage.  

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4 hours ago, MikeC5 said:

 I have a tough time believing that the stress on a crankshaft from lying horizontal (due to its own weight) would have any measurable effect on the straightness/concentricity of the main bearing journals. 

Gravity moves everything at an atomic level. Even old glass is thicker at the bottom of the window. The crank does a bit of movement running in the engine, an argument for multiple main bearings.

Edited by JFranklin
added thought (see edit history)
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17 minutes ago, JFranklin said:

Gravity moves everything at an atomic level. Even old glass is thicker at the bottom of the window. The crank does a bit of movement running in the engine, an argument for multiple main bearings.


 

Wow....a correct observation on the molecular level. When you step on a concrete slab 12 inches thick it also deflects.......a concept that most people can’t comprehend. Like understanding that a granite counter top is 99.9 percent empty space. 

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 You can suspend a crankshaft for a Model J by the two outer mains and deflect it .05 by pushing it with your finger.........steel is plastic.........just because you can’t see it flex doesn’t mean it’s not flopping around.

CBC1BA57-D744-49E3-9E14-CB63A797C961.png

Edited by edinmass (see edit history)
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Not be pedantic but in engineering/strength of materials - terminology, I think your example of bending the crankshaft is an example of 'elastic' bending (bending within the 'proportional' or 'elastic limit' of the material).  This means no plastic deformation is occurring (i.e., no permanent bend).  If the crankshaft in your example was plastically deforming for a portion of the 0.05" deflection, it could be forced back to true by pushing the other way hard enough that it will yield the opposite way just enough to end up straight again (crankshaft straightening process does this).  If you take a paper clip and bend it back and forth it fatigues and breaks quickly.  If, on the other hand you stay within the elastic limit of the material (no permanent bending), it will last a long time (possibly an infinite number of deflection cycles, depending on material).  Generally speaking, these reverse bending cycles aren't good for the part as it can degrade the fatigue resistance properties of the alloy in the localized area where the plastic deformation occurs.  I'm not sure that glass is a good example for comparison because it more closely resembles a really viscous liquid, at a molecular scale, than a solid from what I've read.  As such, it 'flows' slowly due to gravity.  

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  • 2 months later...

Dredging this thread up to post this slightly relevant photo I found on FB. These are late 60s Pontiac cranks. I guess GM was not so worried about how to store them. 😉

(Yeah, I realize they are rough castings and not machined yet).

 

Gotta like the bow tie!

 

 

Crankshaft Storage.jpg

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