Currently I have a Comp 268H cam with their recommended valve springs (part 942-16). The cam has .456 lift with a 1.6 rocker. Lift bumps up to .484 with my 1.7 rockers... I do at least know my combo works fine at that level of lift, even with pressed-in studs. Now I'm considering a cam change. Comp recommends the same valve springs I'm running now with this cam, (XH268H) which is a split pattern with .510/.512 lift. That's of course with a stock rocker ratio. With 1.7's it should go to .541/.544. So... Something tells me that might be approaching questionable territory. I'm pretty sure the springs won't be a problem, but has anyone here run valve lift that high with these or similar heads? Should go back down to 1.6 rocker? And how 'bout those studs? Am I asking for trouble by continuing to use those? Keep in mind this is a street engine that doesn't even see 5000 RPM all that often... Thanks!
Alright, I knew I was pushing my luck with those anyway. That I can fix. Main thing I'm concerned about is those lift numbers...
There has definitely been some porting, but as to how extensive I couldn't say. Perhaps my money would be better spent on different heads anyway...
Comp recommends against running the XE cams with pressed in rocker studs. It's not just the lift, but the lobe profiles that will exert greater force on the studs to work them loose.
.540 is about all your gonna get out of it before the retainers are gonna get close to the guides so a .512 lift would be max i would go Ive ran press in studs in a 7k rpm windsor with a 230/230-.512 lift cam on a 110 with no problems I ran the motor hard for 5 years and was still fine when i sold it so ymmv
Ah, Joe you're gonna get me in trouble. You're what they call an enabler! So if I end up getting this cam, the 1.7 rockers need to go... And I don't need to be looking at anything over .512 lift unless I change heads, right? So I guess this other one I'm looking at with .519/.523 (XE274H) is out of the question? Thanks for the help, everyone.
No, that's part of why I'm asking about it here. Those are the springs recommended for the cam so I wouldn't expect them to be a problem, but I'd rather not just assume...
i would urge you to stay right around .500 jmho lunati's bracket master II is the cam i ran fwiw i was always happy with it's idle and manners in the stock headed motor
The 00111 must be a new cam they may had discontinued the cam i had and superceeded it with this one. It looks to be similar in specs with a hair more exhaust duration and lift (good for stock heads as they breath crappy out the exhaust)
