pdxmotorhead

I've seen more than a dozen engines blown with broken valve springs after being pulled out of storage.
The higher pressure the spring the more likely it is to happen.

On some sprints the springs are trashed about every 20 races..

Nobody I know road racing a top shelf motor stores their engines with the rockers on.

I've measured springs that have been in storage and found 50+ lb differences between the ones that were tight and the ones that were loose. Also can often measure significant differences in unloaded spring height..

Attention to Details for the win...

grinder11

iTrader: (1)

I've also broken a valvespring in the first 300 miles!! Happened as I came to a 4 way stop at 5:00 A.M. on my way to work. Might have been turning 1,400rpm. Had a good part of my savings in that engine. So it's not always age. Thank God for dual springs!! There is something to be said about a part, or part, that has proven reliable. On a really high lift cam, say .650"+, yes, you'd be foolish to run them year after year. Since my cam is close to stock lift, and I believe PAC springs are superior in quality-and they have better quality control, than the GM springs, I figure my springs are pretty safe. But even if I had warned somebody, and they didn't listen, there's no way I'd stuff salt in their wound as they lay there hurting, even if they wounded themselves! ! That's like visiting somebody in the ICU with Covid, who didn't get vaccinated. I'd never stand there and tell them "you asked for it". That's who I AM.....

grinder11

iTrader: (1)

I totally agree with you. I would also check them. But, and I don't know who posted this after you did, if I would EVER find springs that hadn't been run, or run in awhile, and I found variances of 50 (FIFTY!!!) pounds from one to another, I'd shitcan them for sure. Just as certain, I'd NEVER buy ANYTHING from that company again. I "upgraded" my rocker trunnions several years ago with a kit from a well known cam company. Their kit is pure junk, with a lot of failures on the forums. I can guarantee you I'll never buy anything from them again, either. I don't care how good it's "supposed" to be......

Che70velle

iTrader: (6)

If this is a high rpm race build, I’d say change them out. If this is a street car that’s just gonna cruise on weekends and occasionally see 6500 rpm, run it as is, no worries.

Che70velle

iTrader: (6)

This is a myth.

CattleAc

iTrader: (7)

Along the lines of..."We're from the I.R.S, and we're here to help..."

01CamaroSSTx

iTrader: (3)

https://www.guntalk.com/video-post/m...weaken-springs

Finding replacement springs for my Automag and Coonan won't be easy.

Kawboom

Its an over-simplification.

Basically in order to deform a spring, you have to compress it past its elastic limit, but the thing about spring steel is that its elastic limit is not a strongly defined value, and the tension on every part of the spring wire is not even, with it being much higher on the outer surface than inside the spring core. And if you have a high-lift cam, you need high lift valve springs that have few coils per inch. This means the torsion on each little part of the spring steel is higher than stock or lower lift springs, so in use it can be more likely to lose tension.

Also, valve springs, whether stored under compression or run in heavily used engines, will 'relax' and are expected to lose something like 10% of their tension, and a small amount of spring height, and then maintain that final 'relaxed' tension more or less indefinitely. The same phenomenon happens to suspension springs, leaf springs, all sorts.

Basically, from what I know about this, if you took your valve springs and compressed them all .600" and then stored them at that compression, or installed them in an engine with a .600 lift cam and drove them 100,000 miles, you will have your springs creep and relax somewhat. Its kind of unavoidable.

A potential issue is that in the stored engine the spring relaxation can be uneven, but if you run the springs they will even out eventually.

Please swap them if they are even slightly rusty, or they will crack.

Che70velle

iTrader: (6)

I’ve had 30 round mags loaded with .223 for over 20 years. I pull one out every so often and put lead down range. They work flawlessly. I keep a couple thousand rounds in magazines at all times. Big difference here however between a valvespring and a magazine spring. Spring steel is very resilient in either case. I wouldn’t second guess changing out springs in a race engine. That’s a no-brainer for me, but for a street car, that’s very different.

jasons69chevelle

Heat cycles is what causes valve springs to lose tension. There’s a guy on the Chevelle forum that clamped a couple valve springs for 11 years they are the same 460lbs of pressure and length from the first day he clamped them.

01CamaroSSTx

iTrader: (3)

And how did he know this? By checking them..

grinder11

iTrader: (1)

Can't agree more. It never hurts anything to check something, and maybe even double check. I'd pull the springs, bag them, with the retainer, 1 at a time, and mark which cylinder#, and which valve, I or E, the spring was installed on. Most engine/machine shops have the checking capability. If I placed a bet, OK/not OK, I'd say he's gonna be fine.....

G Atsma

Gotta love zip-locks and Sharpies.... saves lots of headaches later...

grinder11

iTrader: (1)

Exactly!! I usually mark the bags with a paint marker. Seems more durable than indelible ink....