Originally Posted by AKlowriderZ71

I'll let you know Billy.

Originally Posted by fastrt

Bud, your pops Know his stuff for sure man, thanks for sharing that great info with us!! He is not the first guru that said patriot is crap. I am running them now, but not even close on the LS1. I have been told that the off the shelf guys get their springs from brazil, where the bad 918's came from I think. These springs are the ones most of us run. Pac makes a great spring, and even makes custom coiled springs for any app. The other top 4 guys you wrote about are on the same level!! My head porter does port design for some nascar teams, and flow testing and design for a dozen other high end race teams. He has tested just about every off the shelf ls1 spring, and he found that the spring rates wont allow the valve to reach the full lift of your camshaft. He said that you would get ~.550" at normal 2000-3000 rpms around town, but a WOT you get less than .500" lift out of a .600" lift cam.

He designed a custom set of LS1 valve springs that he gets PAC to build for him, along with a Ti retainer. Seat pressure and open pressures were higher than your normal PG, or PRC. But he claims they will net you more stable valve events, and get close to cam lift. Which = more power. They are duals too. I am excited to try them, but the price would turn most away....~$550 a set.... He also says that with a street/strip app, you will not need to change them evey 30k. I asked him about when I should change mine on the "getting built now" LS1, and he said" if the motor last 100k miles then change them then"...lol

Originally Posted by budhayes3

Thanks Roger, my gut feeling is that they will look pretty good, even at 60k.



Thanks Eric I definitely trust my pop as I know how smart and meticulous he is, and how much R&D he does Sounds like you have a real nice contact there. Could you elaborate a little bit about the spring rates not allowing the full lift? Is that with springs with high seat pressure, such as duals? Do they depress the lifters or something? Do you know your builder's take on beehives? (pretty sure that I mentioned that my dad doesn't like them)

Originally Posted by fastrt

yes sir your pops is dead on!! Now I am no expert on valve springs, but I have been educated on the ls1 offerings by several high end builders and machineist. The lift issue has to do with the kind of material the spring is made from, and the part of the world it was made. The reason the springs are cheap is because they are made in brazil out of a "good enough" material. You want made in the good ol' USA!! The seat pressure and opening pressure and fatigue of the spring wire is why they dont alow for the lift. Basicly a soft cheap spring vs a harder expencive spring.
My head porter guy was able to experiment with lots of springs on a cutaway head, like the vids you posted. Thats how he came up with the springs he sells to his LS1 customers.

Originally Posted by budhayes3

That's awesome info Eric, thanks a ton! Unfortunately for myself, and everyone here that I can share info with, my pop has never gotten into the GENIII stuff, so he's not an LS guru, but he's definitely an engine guru, and most of what he does and knows still applies. I have to ask him if the LSx engine that he's building is his first GENIII or not, now I'm curious. Thanks again Eric, I totally appreciate your help and input!

If I may be so bold as to ask another question (sorry to ask so many but it's apparent that you have a top notch contact )...do you have your builder's take on GENIII lifters...as in how much spring pressure is too much? Or, will the high pressure springs shorten the life of the factory LS7 lifters that everybody uses? I've seen some of the dual springs, such as the Cranes, have as much as 150# of closed seat pressure and 420# open Do you know what lifters he prefers?

I found another video courtesy of Comp Cams CPG Nation, about how to achieve proper rocker arm geometry. There doing it on an Small Block Chevy and not a LS, but it's still good info. The importance of checking the rocker's swipe pattern on the valve tip should definitely be stressed IMO. Click the linky below for the vid

http://cpgnationtv.com/video_detail.php?mId=15046

Originally Posted by fastrt

Bud, i forgot to answer the single vs dual spring question. Heed your dads advice and stay dual w/ti retainer.

He told me ls7 or caddy gm lifters are great. He uses a bar type lifter in his LS6 CTSV. He wanted to do away with the lifter trays, and make a 7500 rpm stable valvetrain. but with that you need adj rockers and custom pushrods. And they are ~$600 for lifters....no thanks.

His CTSV is a stock bottom end, Trickflow heads cnc'd by him, custom cam, vic JR intake, 1 7/8 headers thru a custom irs 9" and it made 486hp on a low number producing dyno. before the rearend it made 507hp I think.

Originally Posted by fastrt

He told me ls7 or caddy gm lifters are great