Featured Technical Myth, or truth? Storing cams and cranks horizontally vs vertically

Speaking of camshaft straightening, watch how this guy does it. Go to the 17 min mark.
Interesting how he does this with an air chisel.

 

I'm getting to the age where "saggy crank" sounds scary. I hear they got a pill for it.

 

I like a good spud cam, you know, the ones that make your engine go potatopotatopotatopotatopotato.

 

Wow, thanks for posting that. Given he was able to adjust (ie, bend) short little sections of that cam with short bursts from an air chisel, I would think that a solid roller cam would be all out of whack just from running in an engine.

 

Amazing to watch the above machine shop video straightening a rare Crowler cam shaft that was apparently damaged when a lifter disintegrated, not sure what the labor rate might have been, but 1.5 hr's. labor on a difficult to find camshaft probably worth the price.

 

My buddy that builds engines told me about that with air hammer. BUT you want a radius on the edge that would be normally sharp. the guy did not show that detail i don't think i kind of skipped through the video so i might of missed it.

 

But if I got rid of the wallet chain I can't hold on to that persona that I'm a 22-year-old rebel without a cause. (Just ignore the fact I'm double that now with a few extra years added on for good measure lol)

 

They may take up the same volume but with limited floor space I have found it convenient to hang them up by the snout end. (labeled for stroke and undersize BTW)
My cams are stacked flat on a shelf.

 

I'd say this story about storing crankshaft's horizontally needs to be filed along with other notions like storing a battery on a concrete floor will make it go dead, and giving the the car a rake by jacking up the rear will give you better gas mileage 'cause it's going downhill all the time.

 

Oh no, now your crankshafts will be too long for your engines!

 

No problem, I'll just hang my blocks in the same way. That way I can increase the bore centers and run a bigger bore. Win/win.

 

I store mine like this:

 

Oh No !, those are gonna stretch

 

I have watched this for a while. Pretty good stuff. I have some hanging. Some sitting upright in the flange and some laying flat. I have never had an issue. As for cams. I typically never throw a cam box away. Easy to store /and know what’s in the box. They stack good too.

 

I also heard this early in my life and thought, that’s kinda hard to believe! Later in life , while working as a machinist, I learned just how “ flexible “ steel and iron really is.
Luckily, I don’t have that many cranks to store, so they are on end, out of the way, so I don’t hang my chain drive bill fold on them!




Bones

 

I'd rotate the jack stands 90 degrees to keep the crank in place.

 

YES, but "flexible" and "plastic" are two different properties. Iron or steel cranks are flexible, but plastic - not so much.

 

hmmm, that could be why they keep falling off.

 

I love this post as it brings back alot of teenage memories. I was told this same thing at age 13 or 15 hell I don't remember. But The machine shop always said this and they even took it a step further as they said it was best to hang them. I knew those guys built the best engines at the time so I always took it as truth. However maybe the guys at Eagle missed the class on the proper way to store a crank as if you look at how their box is designed with the part number on the end and handle holes on the end. I think they stack them on the shelf in the box laying down flat like in the pic. Either way every Crank or cam I saved I always stored them vertical and probably will always as that is what was told to me by some of the best engine builders I have ever known. However those guys could have very well been messing with me because when I first started skipping classes and walking over and hanging out at the Race shop . They did have alot of fun with me. I will never forget the time Don ask me to call over to the supply house for him and order a set of "Piston return springs" for a SBC engine. I was the butt of that joke but God damn those were good times!

 

I don't know if you read my previous comment about landing a crankshaft on my little toe a few years ago but your hanging invention is genius and to be done even easier using some angle iron and some black iron pipe (and some fittings) from the orange box store, thank you for giving me the inspiration I can't believe I never thought of that for storing camshafts or crankshafts.

 

Paper towel zip tied around journal. Drip oil onto paper towel.

I'd say it baffles me how people can be so lazy but actually it doesn't.

 

Its more or less a myth. You'd need a really big crankshaft to make any sort of deformation problematic. At that size you'd also have deformation issues if you stood it on end, too.

Years ago I ran a finite element analysis simulation on a SBC size crankshaft and the deformation was an order of magnitude less than the machining tolerances possible.

They're stored on end to save floor space.

 

I had a uncle who was married into the family and he was Always being teased by my Dad and other Uncles. He was a tight ass and was always complaining about the cost of everything. So he would buy his tires 2 at a time and they would always be used from the salvage yard. Nothing wrong with saving money, However he was over visting at our house one day bragging about the hardly used 2 front tires he just bought for $15.00 but was Also bitching about the gas milage he was getting from his and my Aunts Chevy Caprice. My Dad noticed that he had slightly taller tires on the front than he had on the back So my Dad being the smartass he is decided to mess with him and Told him " No wonder you are getting such shitty gas milage!" "You are constantly driving up hill" Poor guy was so gullible that while my Dad was in the house visting with some of my other family he got out his bumper jack and four way tire tool and swapped them around.

 

I recollect hearing the "myth" back when I was a pup. However, I don't know if I was told it wrong or if I processed what I heard wrong because I thought vertical was the problem and horizontal was the cure. That made sense to my pea brain because vertically all the mass of the crank is on that bottom dogleg, while horizontally the mass (weight) is divided out over multiple contacts. But because I have so many holes in my head, I have an open mind about most things and I'm willing to sell my vote.
But let's not lump cams in with cranks because they are not the same species. Cranks are a stack of levers, zigging and zagging, while cams are merely a stack of biscuits.
Frankly, (rhymes with 'crankly') we should probably just hang 'em like Henry did.
V
V
V
V

 

Doesn't matter how they lay when they hit my scrap trailer.

 

Swapping the tires around like that might could help with the mileage. It's a 'half-fast' overdrive gear.
Your dad's a genius.

 

In order for metal to exhibit signs of fatigue, it has to be cycled at loads somewhere near its yieild strength. No cycling no fatigue.

Fatigue failures have characteristic beach marks on the fracture surface.

Bending in storage isn’t going to happen if the load isn’t sufficient to exceed the yield strength and enter the area of plastic elongation.

That’s not going to happen considering that cylinder pressures are a thousand psi, and a Diesel may be well over 1600 psi. Apply that to a piston with a four inch bore for comparison, and you’ll quickly conclude that a crank without the capability of withstanding its own weight in storage without bending isn’t going to last a single revolution in a running engine.

 

I believe this myth came from large electric motors and large steam turbines. I’m talking 1000 + hp electric motors and much larger steam turbines. When these are stored the rotors are rotated 90 degrees every few months, if left (many months or years) with out turning the rotor will sag, not a lot but enough to cause problems. These rotors weigh tons and are supported on bearings 6, 8 , 20 etc feet apart.
Dan

 

A lot of it comes from returning Navy veterans from WWII era but was more specific to the long skinny through-hull shafting.
It got mis-applied to automotive and agriculture cranks by these vet's (early hotrodders) and spread from there.

 

When they ship the generator portion of wind turbines they have a little pony motor rigged up to spin them at like 1rev per hour or day or whatever. It's not because of the weight though, it's because they don't want all that vibration happening on just one part of every single rolling element.