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How long would you leave valve springs compressed? #2428658
01/04/18 01:27 AM
01/04/18 01:27 AM
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mickm Offline OP
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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?

Re: How long would you leave valve springs compressed? [Re: mickm] #2428663
01/04/18 01:46 AM
01/04/18 01:46 AM
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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 work shruggy 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 shruggy
I haven't ever done that on any of my motors, solid lifter , hydraulic lifter or roller lifters, race or street motors twocents
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 work
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 twocents scope
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 scope

Last edited by Cab_Burge; 01/04/18 01:48 AM.

Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Re: How long would you leave valve springs compressed? [Re: Cab_Burge] #2428666
01/04/18 01:51 AM
01/04/18 01:51 AM
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mickm Offline OP
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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.

Last edited by mickm; 01/04/18 01:52 AM.
Re: How long would you leave valve springs compressed? [Re: mickm] #2428672
01/04/18 01:58 AM
01/04/18 01:58 AM
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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 work scope up
Recheck and reset the lash as needed after breaking in the cam up


Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Re: How long would you leave valve springs compressed? [Re: Cab_Burge] #2428674
01/04/18 02:00 AM
01/04/18 02:00 AM
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mickm Offline OP
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Originally Posted By Cab_Burge
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 work scope up
Recheck and reset the lash as needed after breaking in the cam up


Good idea, thanks! up

Re: How long would you leave valve springs compressed? [Re: mickm] #2428679
01/04/18 02:10 AM
01/04/18 02:10 AM
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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.

Re: How long would you leave valve springs compressed? [Re: mickm] #2428689
01/04/18 02:31 AM
01/04/18 02:31 AM
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Loosen up the shafts....


Tony

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71 Dart Swinger 360 10.318 @ 128.22(10-04-14 Bakersfield)
71 Demon 360 10.666 @122.41 (01-29-17 @ Las Vegas)
71 Duster 408 (10.29 @ 127.86 3/16/19 Las Vegas)
Re: How long would you leave valve springs compressed? [Re: 70AARcuda] #2428702
01/04/18 02:56 AM
01/04/18 02:56 AM
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Dave Hall Offline
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I think for storage purposes it's always better to have the valves closed.

Re: How long would you leave valve springs compressed? [Re: mickm] #2428717
01/04/18 03:40 AM
01/04/18 03:40 AM
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madscientist Offline
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What difference does it makes? As soon as you put the retainers on the spring is loaded?

Heat is what kills a spring.


Just because you think it won't make it true. Horsepower is KING. To dispute this is stupid. C. Alston
Re: How long would you leave valve springs compressed? [Re: 70AARcuda] #2428727
01/04/18 04:18 AM
01/04/18 04:18 AM
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mickm Offline OP
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Originally Posted By 70AARcuda
Loosen up the shafts....


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

Re: How long would you leave valve springs compressed? [Re: madscientist] #2428729
01/04/18 04:22 AM
01/04/18 04:22 AM
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Dave Hall Offline
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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.

Re: How long would you leave valve springs compressed? [Re: mickm] #2428841
01/04/18 01:02 PM
01/04/18 01:02 PM
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polyspheric Offline
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The only thing that lets me stop thinking about it: take out the pushrods.


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Re: How long would you leave valve springs compressed? [Re: mickm] #2428888
01/04/18 02:36 PM
01/04/18 02:36 PM
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Listen to poly - everything else is just opinions without data it seems.
Not sure how you could go wrong with leaving the pushrods out.

Re: How long would you leave valve springs compressed? [Re: A727Tflite] #2428917
01/04/18 03:25 PM
01/04/18 03:25 PM
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mickm Offline OP
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Originally Posted By Transman
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.

Re: How long would you leave valve springs compressed? [Re: mickm] #2428922
01/04/18 03:30 PM
01/04/18 03:30 PM
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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 work
As far as wiping any good brand cam lube off when setting the valves, DON'T tsk grin
Assemble the motor, set the lash, seal it up and make sure and prime the motor just before starting it up
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 up
Good luck thumbs


Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Re: How long would you leave valve springs compressed? [Re: mickm] #2428929
01/04/18 03:39 PM
01/04/18 03:39 PM
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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.

Re: How long would you leave valve springs compressed? [Re: mickm] #2428956
01/04/18 04:34 PM
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Originally Posted By mickm
Originally Posted By Transman
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.



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.


Just because you think it won't make it true. Horsepower is KING. To dispute this is stupid. C. Alston
Re: How long would you leave valve springs compressed? [Re: mickm] #2428965
01/04/18 04:50 PM
01/04/18 04:50 PM

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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

Re: How long would you leave valve springs compressed? [Re: mickm] #2428968
01/04/18 05:02 PM
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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...

Re: How long would you leave valve springs compressed? [Re: mickm] #2429164
01/04/18 08:42 PM
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but it lets me sleep better!!!


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