Technical Myths … or old wife’s tales about engines

Just got back from a dyno test on one of our engines and while there the discussion turned to valve springs on a hot rod engine going bad from setting for a year on an engine being stored!
Then we talked about storing crankshafts standing on end, because they will bend over time stored laying flat!
What are the thoughts of the HAMB on these two myths or truthes?

 

Springs might have some truth to it, just like relieving the tension in a torque wrench between uses. But cranks...I kinda doubt it, the stress on a crankshaft laying there, is nothing like that in a spring being highly compressed.

 

I worked in auto parts stores for years. Every store I worked at carried crankshaft kits. They were all stored laying down. Never saw any that were bent.

I also worked in a machine shop that did lots of heads. We got heads from wrecking yards all the time and I don't remember any extra problems with springs from heads that had been sitting.

 

I’m with Jim. I think cranks are stored standing up in a corner to save space, or if a place has many, they are in/on a rack so one doesn’t bump them and play a dominoes game.
Makes sense on springs.

 

Funny, you should mention “ the dominoes effect”! The shop owner said he was afraid of that! We are taking him an old crankshaft rack that we don’t use anymore,Saturday!




Bones

 

Same old story with camshafts , after 40 + yrs. of building never put a straight cam on shelf in box and used 5 years later and found it had core shift due to gravity!

 

Two words I wasn't taught in High school that might apply here...plastic deformation. Not saying they apply here, but maybe they do? As for Jagmech story about cams and core shifting...anything's possible?

I'm with Jim, onetrickpony, Budget36 and now Boneyard51. maybe but not likely. Final answer.

 

Plastic deformation over time sounds like "creep". At ambient temperature, that is a mighty slow process.

Cheers,
Harv

 

Chevy 6 blocks freeze at 33 degrees.

 

Years ago I knew a guy that always put a clothespin on his steel fuel line between the mechanical fuel pump and the carb. He said it prevented vapor lock.

Sort of a nut I think.

John

 

I'm betting that more cranks get tweaked from being on end and knocked over than from laying flat.

 

Running an engine with open exhaust ports will burn the valves.

 

On the valve spring thing, I knew a guy in Texas in the early 70's that ran a 427 Chevelle in what ever a stock 69 Chevelle with a 427 in place of a 396 would run in then. They never ran at Little river but towed to the NHRA tracks around the south west. I know that as soon as the car was back in the garage after a race they popped the valve covers and backed the rockers off. His wife usually ran the valves before they loaded the car up to to to a race and she may have been the real mechanic in the family.

As far as cranks go I have been in a lot of shops over the years that had crank shaft racks that they hung cranks by the flange under.

 

I replace my valve springs every 2 seasons, high lift solid roller cam. As far as this crank shaft crap? I think that is total BS.

 

Simple verification really, feel free for anyone to do it.
Take a fresh crank, have it checked.
Store it as you will, heck, lean it on the corner.
Now take it back to the same place and hope that after the years of storage, the machine is exactly the same shape. Now have it rechecked.
I don’t have the effort.

 

My opinion is...100 people, 100 opinions, some same, some not!

 

My distributor must be a tooth off, even though you can rotate the cap 45 degrees when setting timing.

 

Any you guys scrapping engines with bad oil pressure. Like 10 psi at idle. Let me know.

 

Well, that's just, like, your opinion, man.

 

All engines run the best hot ! And right before they come apart

surely I am not the only person that I have been told this

 

Oh man, terrible news!

I've had my crankshaft stored horizontally all these years, WITH THE WEIGHT OF THE PISTONS ON IT TOO

How's it not warped?

 

This aggression will not stand, man!

 

Totally agree with valve spring deal on high pressure application, always backed off rockers when putting 287 c.i. race Nova to sleep for winter. Machine shop I deal with ( same crew after 40 years) hangs cams they use to fit bearings, asked the old boss about that, he said , "well, can't hurt" then added, call Isky , ask how they store cams.

 

Well, I have blown my share of engines. I can say I’ve felt an engine rev few hundred rpm higher and feel free, right before the bang.

 

You mean this guy?




Bones

 

Alot of stuff is hold over from days gone by. If you look at a model T crank or an early 6 cylinder crank maybe. How many times have you heard my car is pulling to one side I need to adjust the brakes . With hydraulic brakes adjustment has little to do with pulling. I used to do brake jobs a Sears in packing wheel bearings you always added a little extra grease for looks The only grease that does anything is what is in the bearing.

 

feels free right before the bang is the valve springs going away ,,,,less parasitic drag=more rpm +hp =boom
fabricator john
miss you dad

 

I would think a flat tappet valve spring with 150 lbs of seat pressure on a race engine should have the Valve train backed off if it's going to sit for a few months. Most street springs 80-90 lbs. closed could probably sit for years. I have both and I notice the car I race and street drive a few times a year the springs will fall off much sooner than my 45 year old original stock springs.

 

I always attributed this saying to a lean condition.

Like finally got some good air. It ripped ass right up until it detonated itself into the ground.

 

I was told by a metallurgical engineer the only time you need to worry about springs is if said spring was worked past it's fatigue point, even then, backing it off won't save it, it's time for new springs