Z06_1

The new kid in town -

PSI - LS1515ML Beehive 1.290" .630" N/A N/A 140lbs@1.950" 405lbs@1.300" 408 .000" .650" 1.225"

The current gold standard -

PSI - LS1511ML Beehive 1.290" .630" N/A N/A 130lbs@1.800" 370lbs@1.175" 384 .000" .625" 1.100"

A quick search seems to indicate folks haven't caught on to this new spring yet (out for about 2 months according to the PSI engineer I spoke to today).

Basically, this is an LS7-specific spring, with the same qualities at the gold standard 1511 (about 6% more open pressure, and of course this will vary with the cam in use), without the hassles of trying to shim an LS1/2/3/6 spring to work with the longer LS7 valves.

It would be assumed due to the slightly stiffer rate that spring life might be slightly impacted, relative to the 1511, but as the PSI engineer told me (and I agreed) any difference is likely to be minimal, within manufacturing tolerances (in other words, a 1511 is just as likely to break at 20,001 miles as a 1515 would be).

Looks like there is additional overhead for all you monster-lift cam folks as well.

And for all the Spintron fans (me included), of course there are a few variables here (overall mass and associated harmonic profile) to account for.

It looks like a winner to me.. Enjoy!

AZDANZ06

So is that engineer saying these springs are only good for 20,000 miles??

edmundu

.650 lift isn't that much, given an LS7 engine. Most all of the "street" LS cams are in the .650-.660 range. So this doesn't seem like a good choice....unless I read the specs wrong?

Dirty Howie

Looking forward to another Spintron Test


DH

AZDANZ06

Maybe these springs can help those SS Valves control the bounce at 7000 RPM's

Dirty Howie

Maybe they can also help keep the hollow valves from flying apart


DH

AZDANZ06

Mine wont break, the valve guides were properly done with PM Guides

Dirty Howie

Don't forget your Wiggle Testing. Its mandatory for hollows, much more so than solids.


DH

AZDANZ06

But those damn soft bronze guides will wear out before your valves Howie, might want to put them on your preventative maintenance list every other oil change or so

Lawdogg

Bronze guides longer than oem for the win.

Mark2009

The OEM spring is heavier than the original PSI. Sounds like the new PSI is a physical copy of the OEM which means it's no lightweight... therefore it would be unlikely to be on my shopping list.

'06 Quicksilver Z06

According to the graph here, dual springs with the stock cam will do that.

https://www.corvetteforum.com/forums...post1582784966

AZDANZ06

I am just messing with you SS Valve guys, it would be boring around here if we all agreed on something

Z06_1

Well, he made that comment when referring to the gold standard (1511's), and then we extrapolated from there.

Of course, YMMV - many factors in predicting when someone should change their springs - cam lobe profile, cam lift, initial preload, how close to full compression / coil bind, running engine hard when cold, on and on.

I got the impression the "20K mile change interval" comment was PSI's version of a "guarantee", as in "if you change them every 20K miles, you'll never have a failure". Most of us will run them longer than that, being the super-awesome-dare-devil gamblers we are.

I had a stop-watch on this thread to see how long it would take for things to go sideways with the "LS7 Valve Train Hall Monitors" (of which I am a proud card-carrying member), and I am not disappointed in their performance.

vertC6

This would be the second time they made changes to this spring, I had a set of 2008 with the spec card inside in the seat pressure and open pressure was even less. When I spoke to the engineer (last year) he said yes they were heavier pressures now, but when I emailed Jason at Katech he didn't know about it.

Typically they can run higher lifts with this spring because the seat is set higher on the LS7 head

Dirty Howie

Katech and Richard both recommend them. No worries .........


DH

Z06_1

Keep in mind, technically the 1515 is a new spring, based on the 1511. 1511 was designed for LS1/2/3/6 VT's, and must be shimmed to obtain proper Install Height.

1515 is specifically designed for the longer LS7 valves, no shimming required.

Z06_1

Well, they allow .025" more lift than the 1511's a lot of folks are already using, so whatever that is worth to you (maybe not enough of a difference depending on application).

For example, one of our LS7 VTHM members is on the fence about using the 1511's because they were so close to coil bind with his cam - these might be a solution for him.

Z06_1

I am hoping Jason from Katech might jump into this thread at some point and either offer to test it or report they already have. Again, this is a new spring that might be quickly adopted as the new defacto standard with a clean Spintron bill of health.

AZDANZ06

I am running 1511's with Katech Titanium Retainers with a stock cam, install height of 1.8, I think it should last a long time being a street driven car.