Im installing my new cam next week. Its a 238/242,.600/.610 on a 114+4.
I know cam basics and have a general automotive knowledge. What i dont fully understand is the +4. Can someone please explain. Also would there be a big difference in anything if the same cam had a 114+2.

Thanks

Alex

 

114 is the number of degrees between the intake and exhaust centerlines... +4 means that the whole cam is ground so that all of the valve events start happening 4 degrees before the usually would
maybe somebody can help me out, i'm drawing a blank on exact numbers, but a cam ground on a +0 would have an intake center line of 108* ATDC (after top dead center) where as a +4 would have an intake centerline of 104* ATDC

hopefully that will get you started.

 

read this... its from the sticky at the top of the forum...

https://ls1tech.com/forums/showpost....25&postcount=2

 

well Im no expert, but maybe I can help as I just went through the same questions. my cam is almost like your also being 235/242, exc. mine is on the LSk lobe so high lift. mine is 112+2 BTW. the LSA # will determine charactistics of how the eng. will act. generally 114 lsa will idle smoother then 110. but, by adding the +2, that shifts the ICL intake center line so that the intake valve is at full lift sooner, and will shift the power band up below the curve, and lower after the peak. basically you'll get alot better throttle response, fuel mileage, torque down low. I just saw a direct comparison in a mag (aug. 2006 popular hot rodding, page 76) that answers all your questions, and they advance the cam as well as retard it and show you on a dyno graph the diff. maybe you can find it online.
Im sure someone will come on here and clear this up and correct me if Im wrong.

 

http://www.compcams.com/Community/Ar...ID=-2026144213

Great Info here.

 

Thanks for all the help guys.

 

114 is the measured degrees between the center of the intake, to the center of the exhaust lobe. +4=intake centerline which means where the center of the intake lobe is, compared to the relation of the piston at top dead center. so your cam is on a 114lsa, and has 4* of advance ground into it, which puts it on a 110icl. hope this helps.

 

Your cam is is ground with a LSA of 114* with the icl being 110*(4 advanced) your exhaust cl is actually 118*.

If possible you should have the cam degreed to make sure it's in correctly as variables in crank keyways can alter the position of where your cam is in at.
Advancing your cam usually alters your torque curve by having it come in sooner.