Cam and 1.8 rockers
Thread Starter
TECH Apprentice
Joined: Jan 2003
Posts: 308
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From: Mission Viejo CA
Cam and 1.8 rockers I have a 529 534/218 224/114 Comp CAM, hardened pushrods and 5.7 un-milled stage II heads. My current rockers are 1.7 Yella Terra roller rockers. If I ran 1.8 rockers would I have any valve to piston clearance issues?Also what would my lift end up being and would it still pass CA smog?
On The Tree
Joined: Oct 2004
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Originally Posted by Honez
I have a 529 534/218 224/114 Comp CAM, hardened pushrods and 5.7 un-milled stage II heads. My current rockers are 1.7 Yella Terra roller rockers. If I ran 1.8 rockers would I have any valve to piston clearance issues?Also what would my lift end up being and would it still pass CA smog?
. `Remember, rocker-arm ratio changes the clearance, and advancing the cam reduces the intake clearance and increases the exhaust clearance. Milling the heads reduces piston-to-valve clearance, and larger valves usually require bigger valve pockets in the pistons`
the changes excpected after switching to 1.8 :
lift increaces by 10% and accelerates the valves more quickly during opening and closing . by increasing the rocker arm ratio, u get the benefits of higher lift cam without the tuning headaches that often accompany installation of a bigger stick.
wahhab
May not be much help, but I'm currently running 5.3 s2 heads (not milled), comp 220/224 530/534 112 cam w/ Comp 1.85 rockers w/ no problems at all. We run a best of 11.822 @ 116 Saturday. You're new lift will be 560/565. It's not 10% more lift, it's 10% more of the lift ground in the cam. The cam is ground assuming stock 1.7 rockers being the ratio. The calculation is : (current lift).529 divided by (current ratio) 1.7 = .311, .311 times (new ratio) 1.8 = (new lift).550 and .534 / 1.7 = .314, .314 X 1.8 = .565. Someone correct me if I'm wrong. I'd hate to think my lift is .614. 
