Spring life (when to change valve springs?)
 

Hey guys when should you swap out your BTR dual valve springs .660 lift
I know it's based off of cam and usage but what's a rough estimate on a btr 4 cam and would it be necessary to get the ms11051 for added safety? Stronger might last longer? Thanks guys

I do the occasional daily beating going to work and wanting to drag race it every other week and maybe track it every half a year or trimester

from my experience the concensus is every 20k miles. I have always changed lifters, and springs when employing big cams every 20k miles.

I did, I was thinking of every 10k miles 300$ springs isn't to bad 10k miles a year not bad. Having higher lift springs mean anything? Other than support higher lift cams? Last loner maybe for a smaller lift cam?

20K miles was recommended to me for my PSI 1511 beehive springs with a .660 lift cam.

sorry if you misunderstood what I was trying to say. I meant I change lifters and springs every 20k miles.

Checked my old ones
 

I seen this thread and decided to check out my old valve springs that I just changed out while I had the heads off again to replace the worn valve guides (running high lift cam with stock rocker will do that).

Modded engine 31,000 miles ago. Installed a BTR Stage 3 cam (.652 in. .632 ex.) with BTR.660 Platinum springs that WCCH installed. I replaced the springs this time with the same kind and they looked exactly alike.

Barrowed a friends spring tester to check them out (the old ones). The new springs box had these specs on it.
1.300 dia.
155 lbs. @ 1.780"
380 lbs. @ 1.180"
400 lbs. @ 1.130"
Coil bind @ 1.070 "

All 16 of mine fell right into these specs after 31,000 miles.

So I guess all you have to worry about is spring fatigue.That why I like to use duel springs in that if one breaks at least you have a chance that you won't drop a valve with the inner spring holding it in place.

What makes you think the PSI 1511's are only good for 20k miles? Sure, it depends upon your particular cam lobes and driving habits, but what will be your criteria so as to determine at 20k if your springs are still good or not?

I will have the engine checked at 20K miles by the shop (CPR in Mesa AZ) that did my HCI work. If they have any concerns on what they find, I will have the springs checked/replaced.

The car will be going in for ARH 2" headers and ID 720 injectors in a couple of weeks and I will have them do a quick look over of the valve train after ~8K miles. My last Blackstone Labs report had some Ti indicated and I want to keep on top of any potential problems. Katech did not indicate that the PSI 1511s should be replaced at 20K miles but that the valve train needed to be looked at then. My build has the K501 cam and the Katech TiMo intake valves and the Ti retainers. All my previous BL reports had no Ti indicated, it may just be the new parts getting friendly with each other and of no concern.

When I asked this specific question of a PSI engineer last year, his response (paraphrasing) "..I can "guarantee" it is very unlikely you will have a failure in the first 20,000 miles, so if you want to take the approach of "never" having a failure due to fatigue, then replace them every 20,000 miles..".

Now, in the case of a situation (as in mine) where you are running the stock cam, and considering stock GM springs routinely last over 100,000 miles, and let's assume (rightly so) that the PSI's quality control processes are at least as good (or better) than GM's vendor, that might give you some comfort in running them longer.

But if you want to apply airplane-level of proactive maintenance, then change them every 20K.. PSI will appreciate the business. :cheers:

I am running .660 lift with the stock rockers and CHE bronze guides and use a 7300 RPM FSO so my valvetrain with the PSI 1511 sprigs is somewhat removed from stock. Obviously I have some faith in PSI as I'm running their single Beehive springs in this build. Given ~ $15K in the build on the $15K engine, I will look to do more maintenance on it than I would on a stock LS3 which has 1/3 less HP.

Exactly, there are so many variables.. So if someone wanted the absolute minimum spring change interval, 20,000 miles sounds about right. For the majority of Corvette owners, that's probably one or two spring swaps during their ownership. :cheers:

For me that would be at 66000 and 86000 miles, about 3+ year intervals. I will likely make the first, maybe not the 2nd. I picked it up used at 8500 miles and have enjoyed all of it's performance stock and now with HCI.

My NASCAR 358 would require spring changes at 300-500 miles if running the 8400 RPM red line.

With more of a mild cam to small what time would you change springs if you track the car once a month? You do those 5 sessions in a day of 20 minute intervals. I wonder how much beating that will be on the springs plus daily driving it on spirited runs.. drag racing isn't so bad compared to tracking right ? Let's say katech 110 cam size in this case.

Just do what Gearpuller did... at 20k miles, buy a set of springs, but just pull off a few springs and compare it to the new ones. I think springs *breaking* is pretty rare, unless you float valves or bounce them first, so a spring pressure check makes sense - and you can check for gross guide wear at the same time.

I have the Katech Torquer with a .650 lift but also believe in changing out the springs but for a different reason. High revs. When tracking or if you ever over rev but get away with no damage change the springs is what my shop recommends. Thereafter is when the spring fails from over revving I am told.
I too am getting high Ti recently at 23,000 miles.....but I have new trick flow heads so no Ti valves. Told it's the coating wore off on the connecting rods and now it's Ti against Ti rod ends. Not confiormed yet but probable. My Blackstone reports were always 0 now I am 3-20! Good luck

Some of the later MY Z06s had rod wear problems, but I thought it was the ones with the no-lead bearings which, I think, were in 2012 and 13 MY, not your 2011.

My Ti readings had always been 0 including 600 miles after the HCI build, but it was at 7 after 5500 miles on the oil. That was also the first time I took the sample from the pan drain rather than 1/2 way thru the dry sump tank drain.

Big end wear on LS7 Titanium rods is a common problem. Usually occurs on number one and two rods for some reason. Not a clear understanding of why. Ti rods are coated for wear resistance. When the coating wears through the Ti material is ground off by the rods rubbing against each other. Ti material will eventually contaminate the bearings and valve lifters. Pull the oil pan and inspect the big ends of the rods.

https://cimg2.ibsrv.net/gimg/www.cor...5d48d5970b.jpg

I have a 2012 with a March 2012 production date, and just 6,400 miles on it now. (I've had it for the last 1,200 miles.) I remember when the '13's were still selling new from the dealer that a handful of 427 Vert's had catastrophic engine failure due to what I thought was the bearing/CR issue.

In most cases, GM just swapped out the motor and the original buyer was left a bad taste in their mouth about having a collectible vehicle without the original motor in it. However, as I understood it is if you made it to 5,000 miles or so you were most likely not going to succumb to this ailment?

My question is did GM make a subsequent change (apparently they changed to a different main bearing material late 2012 or early 2013) to remedy this particular problem, so that the '14/'15 Z/28's with the LS7 did not suffer from this same problem? And how come not every LS7 with these bad parts suffered a catastrophic failure?

Have you heard of this on 2010 and earlier Zs? From all I have read, it was a common problem in ~2012 when GM went to no-lead bearings, but I haven't heard of it being a problem on earlier engines (my Zis an early 09 built 7/08.

My first Ti reading was 6 ppm after 5K+ mile oil change after the HCI build. An oil sample 600 miles after the build did not have any Ti readings, same as all prior samples. I will probably take another sample at about 2K miles on this current oil to see if the problem continues. The car will be in for some additional work in a couple of weeks and a quick check of the valve train.

Id guess if the rods were rubbing that bad there may be a possible issue with the thrust bearing?

Any high lift cam will go through springs quicker, rpm and heat kills them quicker than anything. Part of the price to pay for having fun

Surprised GM warranties that stuff