I Am Thinking Of Running The Ls7 1.8 Rockers With The 918 Valve Springs. With The 02 Zo6 Cam The 1.8 Rocker Will Put Me At 582 Lift Est. I Think I May Float Running 15 Psi. I Think It Will Be Close. I Only Plan On Running To 5500 Rpm And Shifting. I Do Not Like To Run High Rpm, I Think High Rpm Is More Damaging Than High Boost On Low Compresion. (mo). I Read Another Post Saying That They Had The 918s, 13psi, 595 Lift And They Floated The Valves. I Dont Know At What Rpm Or What Compresion. What Do You Think? Will I Float?

 

I think you will be fine at 5500 rpm. I don't think boost level has anything to do with it. Course I've been wrong before.

 

I've had mine spike up to 15 psi when I was tring to get 12 dailed in and never had valve float, but I'm running stock rockers too.

 

As long as the springs were installed per the manufacturer's recommendation, you should be ok. Some guys have run the 918's with cams nearing .600" lift with no problems. The main thing the boost pressure does is to help unseat the valve when the valve is closed on the valve seat. Intake port pressure is exerted on the back side of the valve helping the valve off the seat. If you have near 140+lbs of seat pressure you should be ok.

Good luck,

Richard

 

Thanks Guys, If I Can Get My Wallet Back From The Wife, I Think I Will Give It A Try.

 

Dont do it IMO. We had a customer bring a car with a .600 cam with 918's trying to run 13psi. Couldnt make the boost and crazy graph. We put better springs in and boom , it made the 13psi and of course more power. Its not that much more to do Crane 832's or Patriot golds and you dont have to worry about it.

 

I hear yeah! It's a close call. I thought about it and I think I am going to leave it alone, it makes really good power as is.

 

I didn't think you could use the LS7 rockers since they're offset or something?

 

I think you use the exhaust rockers all the way around.