Yes, these are exactly the same as O.E. LS6 springs with coil bind at 1.200". An open height of 1.250" puts us .050" out of coil bind at .550" lift.

 

I have been following this thread with some interest. I have a 2002 45K original miles stock LS1 CETA. While the mileage is low and the first 2 owners put less than 10k miles on the car the last owner (I picked up the car from a dealer who got it at an auction) put most of the miles on it and I am finding evidence of mystery stuff at every turn. Judging on the lack of maintenance I have found (at least the oil was changed frequently) I am wondering if the stock springs might have weakened over time verses mileage? I have noticed some noise on the rear passenger bank but with the clutch issues I haven't had the time to investigate it fully. At 20 years this Feb since the car was assembled I wonder if a bone stock could benefit, it seems like the answer is yes from what I am reading.

 

An engine with low miles but many years on it is probably the most prime example of an engine that should get a valve spring refresh. When you stop the engine at least one valve spring sits in the fully collapsed position (because the rocker arm, or arms, stopped at or near max lift of the cam). You don't want to leave them like that for long periods of time.

People in the know, pull the rocker arms off during storage so that the engine isn't sitting for long periods with the valve springs collapsed.








Side note:
I'm always shocked how over looked valve springs are, and the amount of people that want to cam an engine and keep their 20 year old valve springs that wont hold the stock cam anymore, and then put an even bigger cam in.

 

I ordered a set for some 706 castings I have.
I didn’t know Summit had these until this thread. I have been using the GM springs.
Wonder who makes them?

 

My personal experience with my very low mileage LS1 has not proven such a result. At 23 years old it's just about as old as any LS1 engine can be, but it has only 18k miles. It still pulls just as hard to current shift point (~6100rpm) settings as it did 17 years ago when I first bought this car. It has NO trouble attaining rpms or power above ~5500-5700rpm as seen by the example earlier in this thread; the engine revs smooth and strong all the way to WOT upshift. While I did bump the shift points many, meany years ago by about ~100rpm, I've never touched the factory rev limiter nor has the engine been beaten hard by any means. This is a near-stock vehicle that just sees occasional spirited driving as it's primarily used as a show vehicle.

Like most things, this is going to be application dependent and will vary based on several factors, not the least of which is operational history. I don't feel that any fixed conclusion can be drawn.

 

I could be wrong but everything I have read about springs of any type is that sitting compressed or uncompressed doesn't hurt the life of the spring. Its the cycling through its range of motion that over time weakens springs. This is commonly argued in the gun world with leaving magazines loaded for long periods of time versus unloading them to uncompress the spring. Most find that leaving them loaded doesn't change anything with regards to spring life span.

 

I have several boxes of used valve springs labeled from whatever used engine I took them off of and have whatever mileage it had year etc written on the box with whatever type of spring I replace them with kind of a pack rat anyhow, all this rambling back and forth could be solved with some science if someone wants me to mail them all these old used springs and then they can check them haha

 

I could be wrong too. But with my current knowledge I have a hard time seeing a spring stored compressed, versus un compressed, having the same exact strength when tested after a good period of time sitting that way.


I've also had valve springs **** the bed before, swapped them for new ones, treated them the exact same way in the same exact engine, and they didn't fail. Go back 10 years in my history and I have a post where I broke the tips off of 8 OEM valve springs, around 8 years on them and around 150k miles. Put in some newer, actually used springs, car ran for years getting bounced off the rev limiter every day with zero issues. I've also changed many broken valve springs.

And on top of all that, I can't count how many threads I've participated in where someone had a low mileage vehicle with running issues that turned out to be weak springs. Doesn't happen to everyone, but it happens to enough people that I've seen a trend....


This is also going to be very rpm specific, if you don't rpm the engine, then the weak valve springs aren't going to necessarily show, same if you don't beat on it. Grandmas worn valve springs are gonna work just fine for grandma, not so much for grandson lol



As for the gun clip thing, I've had that thought before too and wonder how many of them have done testing on it in a controlled environment though? Meaning how many tested spring strength before leaving the spring compressed, an actual measurement not just a feel, and then loaded clips and let them sit for a year or so, then took readings versus new.

I know that sometimes we "feel" something is the same. And generally that's all that's needed. But when my glock jams here and there, using the clip that has been stuffed full and left sitting for 3 years, I can't help but wonder what a new fresh clip would do. Maybe someone has at least tested that, but then again it would have to be a controlled test using some ammo or a gun that has a tendency to jam, or at least a tendency with certain ammo, like my glock does. It doesn't like the tulammo very much. If you have a gun that does not have a tendency to jam, then swapping old and new clips may not tell you anything at all.

 

There's going to be lots of banter on this. Bottom line for me is I've seen too much in my personal experiences to not change/maintain springs.

 

I have a have a set of castech stamped 706 on my ls3 pistoned lq4 I would not trade for the moon, it has regular old blue LS6 springs in it and my new junkyard LQ9 has these new summit springs is the only difference the paint? Did they just scrape it off? I also would like to know who makes them!

 

Though it may not seem intuitive, what you've outlined is, in fact, consistent with the experience I've had with my very low mileage LS1; performance and ability to attain 6k+ rpm is no different now than it ever was, even with its life-long history of sitting for months at a time during off-season storage with no special attention paid to the springs. It just hasn't been an issue with mine or several other local examples that I've been closely familiar with which fall into the same category.

On the other hand, there are plenty of operational variables which can take place over ~2 decades that may impact longevity, so you really can't just look at mileage vs. age and conclude that sitting was the cause. I know of more than one local car that was beaten mercilessly early in its life, then sold to a new owner who kept it for many years as a garage queen. Someone unaware of its early history might assume that simple disuse was the cause for certain types of failures at relatively low mileage...but they don't know what they don't know regarding its history.

And then, as touched on above, there are times when a part, even an OEM part, is just flawed and will fail early in a certain percentage of applications no matter their operational history.

 

While we are on the topic of valve springs, assuming your install height is 1.800, isn’t it best to shim these springs to the minimum .050 clearance even if your valve lift was lower than .550?

For instance, for .535 lift, use a .015 shim. This would increase seat pressure slightly and I have read this would control spring surge.

thoughts?

 

When replacing the springs, is there anything else (as a best practice) to replace at the same time? When looking at the 174002 springs I see there are valve seals (143008) and valve locks (143009) available. Last time I tore an engine down for a rebuild was in the late '80's on a 5.7L GM truck and the heads were sent to a machinist, all I can remember are the valves were ground and some new hardware added (engine had just over 100k miles at rebuild). It looks like the seals are an upgrade, not sure about the valve locks or if those could be done at spring replacement?

 

Jake, you're spot on with your assessment. The install height of our SUM-174002 springs is 1.800". We previously discussed coil bind is 1.200" with a 1.250" open height. This keeps us .050" out of coil bind with .550" lift. To keep maximum valvetrain control with your .535" lift cam you could use a .015" shim. That would put you right at .050" out of coil bind. Keep in mind the installed heights might be slightly off from one seat to the next.

You're right, it's better to have the spring at .050" from coil bind than it is to leave "wiggle" room. Being near coil bind with the valve fully open helps keep the spring stable and uniform at valve closing. Think of the valve being open at max lift. A spring that has too much space between the coils never relaxes. It's shaking and wiggling like a bobblehead

There's quite a bit more to unpack here. Here's a good article on selecting springs and what they experience in our high-performance engines.

We noticed a few mentions of wondering who makes our SUM-174002 springs. Being a private label part the manufacture wishes to remain...well private. When we say these are just like LS6 springs, they're just like LS6 springs

 

I wonder how many of the low mile cars with weak springs are victims of the winter storage start up and idle treatment? I could see them having lots of extra run time that the odometer doesn't report because of that but that's a very specific case and the only thing I could think of that would cause weak springs on low mile cars. Would be interesting to see but impossible to get data from lol

 

I you want to see what's going on, google "youtube spintron valvesprings" and watch the videos that pop up. Pretty neat. You should get one that has a failure near the end of the vid, one a few that don't, and if you keep digging, you should get a few videos of valvefloat - which looks like the valve tip is wobbling back and forth when you watch the vids (so you know what to look for)

 

It's true that cold starts are where a typical street engine sees most of its wear, especially cold weather cold starts, but starting it once or twice a month during winter storage probably isn't a huge factor in valve spring life by itself, assuming they aren't holding the engine at the rev limiter during the run sessions..LOL. But, again, I'm sure there are several factors and combinations of events that could and do lead to seemingly premature issues.

FWIW, I never run mine during periods of storage. It usually sits from some point in October all the way to April without being touched. This process has served me well and led to no issues with my 23 year old OEM engine, or really anything else on the car. This car has lived an easy life and remained mostly stock as I've regularly had other LS1s to play with concurrently, but I do drive it spiritedly when I take it out and it still runs as great as it ever did.

 

You think starting your car and letting it idle during the winter is bad? I'm pretty sure that's what keeps all of my garbage alive when I'm not using it on the road starting it and running it through the gears a little bit even if I can't drive it around much Damn I probably shouldn't put that heet in the gas tank either

 

I always use the valve seals the hat style that have a shim built into them but I've never measure the thickness are these generally any thicker than the stock assembly?

 

Appears to be around .047. These are OEM from GM.