Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums - Camaro5.com - View Single Post - Engine builders please help, need advice on valve springs

Stingr69 · 08-18-2011, 08:41 AM

Ed,
Considering the specs: the LS9 cam has .011" more lift on the intake and .033" more lift on the exhaust. 6° more duration on the intake and 19° more duration on the exhaust. This profile has just a little more exhaust event to cope with the supercharger. In my opinion that just isn't enough of a difference to change the spring requirements .

I did the LS9 cam swap and it works fine with the stock valvetrain pieces. The cam drive gear swap was the only other 100% mandatory change. The LS2 damper is probably good insurance but I did not choose to change it. GM uses it in the LS9 tensioner and the loads on it come from the cam profile, RPM and spring rate so the stock tensioner was deemed good enough for me. If you were to go bigger on the cam then all those pieces would need to be considered.

Hope this helps,

-Mark.

08-18-2011, 08:41 AM	#3
Stingr69 '69 Owned Since '79 Drives: '69 Z/28 LeMans Blue w/White Join Date: Oct 2008 Location: LR AR Posts: 1,848 View My Garage	Ed, Considering the specs: the LS9 cam has .011" more lift on the intake and .033" more lift on the exhaust. 6° more duration on the intake and 19° more duration on the exhaust. This profile has just a little more exhaust event to cope with the supercharger. In my opinion that just isn't enough of a difference to change the spring requirements . I did the LS9 cam swap and it works fine with the stock valvetrain pieces. The cam drive gear swap was the only other 100% mandatory change. The LS2 damper is probably good insurance but I did not choose to change it. GM uses it in the LS9 tensioner and the loads on it come from the cam profile, RPM and spring rate so the stock tensioner was deemed good enough for me. If you were to go bigger on the cam then all those pieces would need to be considered. Hope this helps, -Mark.