How long would you leave valve springs compressed?

I have an engine that is rebuilt and ready to go, but have no idea whatsoever when I'm going to fire it up.

I've left the intake off, as I want to lube the cam right before firing it, but with Iskey rev-lube, I don't need to do that, as that stuff doesn't run off the cam over time.

But if I adjust the valves now, and put on the intake, and it's a year before I fire it, then some of the springs will be compressed for a year.

Will it hurt it to have the springs compressed that long, or should I just hold off and wait?

More info needed, which brand spring and how much pressure? You can always leave the lash loose on all of them until ready to start and run it I have friends who are bracket racers with solid flat tappet camshafts that loosen up all their rockers every winter and reset the lash when they get ready to race again
I haven't ever done that on any of my motors, solid lifter , hydraulic lifter or roller lifters, race or street motors
I do have a old 1000 lb. Rimac valve spring tester so I can remove several springs and test them to see how much pressure they have lost compared to when I assembled that motor to see if they need reshimming or replacing
If the motors stops pulling as hard as it had in the past in the upper RPM range it is time to check the pressure on all of the valve springs
My message is good springs should, with proper lubrication and setting them up properly, should last a long time or a real long time depending on the application and RPM limits

This is a hydraulic cam, .582, 241@.050, so not radical. The springs I don't know, I assume standard springs that come on the mopar hemi aluminum heads. Nothing radical.

So if I just apply a little oil, then they are lubed.

So you are saying you wouldn't worry about leaving them loaded for a longer period of time?

My idea is that after setting the lash, the cam will have turned a number of times, and it would be nice to re-lube it. But obviously I can't do that if the intake is on.

If you don't want to turn the motor over after loosening the adjusters write down how many turns out( down to a 1/8 or 1/10 of a turn) it takes to get a zero preload on each adjuster and when your ready to start the motor tighten them back up the exact same amount
Recheck and reset the lash as needed after breaking in the cam

Good idea, thanks!

FWIW, I turn over any engine with over 350 PSI spring pressure about every 2 weeks; just 90* or so with a breaker bar.
Maybe it's more peace of mind or superstition than anything measurable, but it makes sense to me to let springs relax.

Loosen up the shafts....

I think for storage purposes it's always better to have the valves closed.

What difference does it makes? As soon as you put the retainers on the spring is loaded?

Heat is what kills a spring.

Can't on a hemi, the bolts that hold the shafts in place are head bolts.

That and work. I was just thinking that the springs aren't really an issue but the OP might want to think about keeping it closed up and oiled.

The only thing that lets me stop thinking about it: take out the pushrods.

Listen to poly - everything else is just opinions without data it seems.
Not sure how you could go wrong with leaving the pushrods out.

Hey guys, not sure of the relevance here. My goal is to have the cam lubed, and button the engine up. But if I leave the springs uncompressed, then I have to spin the cam a few times to set the lash on all the valves essentially wiping some of the lube off the cam.

If I leave the engine open, I can just re lube after setting the valves, but that means leaving it open.

So I guess it's really, would you:

a) leave it open with valves unadjusted
b) button it up with valves unadjusted
c) button it up and adjust valves.

If your worried about the sealing of the head gasket don't torque down all the head bolts until your ready to set the lash
As far as wiping any good brand cam lube off when setting the valves, DON'T
Assemble the motor, set the lash, seal it up and make sure and prime the motor just before starting it
I like to pull all the spark plugs out before priming the motor and use either the starter or a breaker bar to rotate the motor while priming it
Good luck

A, leave it and put a bag over it, you know you're gonna change your mind in a year about something.
I put a 360 Magnum together back in 08, been setting on the engine stand ever since. I guess I'll find out this spring-summer if they sag, can't remember if I adjusted the valves or not.

I don't get it. How much and and long do you think the cam lube that is slathered all over the cam is going to be on there as soon as you hit the starter? The same amount as would be if you turn the engine over by hand.

The black coating on the cam and the finish on the bottom of the lifters is what retains enough lube to keep the cam from being dry on start up. Once it's running the cam is lubed from oil thrown off the rods.

Cams don't go flat from it having enough cam lube on them, because it doesn't take much. They go flat because the engine didn't start and it gets cranked to death before starting. They go flat because the lifter doesn't rotate. They go flat because you can get lifters that aren't machined correctly.

I don't install a set of flat lifters until I verify all of them have the correct crown.

I walk past my dragster at least a couple times a week and turn engine over--does it help? Nah...but it lets me sleep better

I think it's harder on the rockers than the springs..750+ open spring pressure kinda deal..I tell everybody to back off the shafts..up here engines sit for 5 months or more...

but it lets me sleep better!!!

How long would you leave a book sitting on a shelf? The valve springs in that engine are probably under no more load than the book shelves in your house or the kitchen table.

I have been waiting for a theoretical engineer type to tell us that a spring sitting in a compressed state,,,valve open,,,,undergoes any more stress than operating at 1000's, millions of opens and closings over a period of time,,,,just wondering. Like a bolt torqued to say a 100 pounds for 10 years,,,will the bolt stretch any amount that after 10 years, would it would show any less torque than initial torque reading.

I believe Monte Smith said not to worry about leaving them compressed. It probably has more to do with the quality of spring material than whether they are compressed or not.

A spring that is properly designed, correctly manufactured and in an application that is allows it to operate within design specs, can sit compressed indefinitely.

- EM

I was told it's the amount of cycles a spring goes through determines it's lifespan.

would spring compression, leaving valves open inviting rust on valves and seats, possibly causing valve sealing issues be somewhat a more important issue to be concerned about than loss of spring tension ?

I would be more concerned using a hydraulic cam and lifter setup in a motor that has intersecting valve centerlines.