Having a friendly discussion with a buddy. On a low compression, 12lb boost engine, which LSA would make more torque down low? 114 or 112?? Given duration and lift being equal.

I say 114, his cam guy tells him 112 would make more power down low. Feel free to vote on which cam you would pick if low rpm torque is what you would be seeking. Feel free to explain also.

http://forum.grumpysperformance.com/...hp?f=52&t=1070


There have a read...and some asprin.

114* cam advanced 2*..stump puller! 114 because theirs more distance between the intake and exhaust which will allow a little more ait in the cylinder then the 112 cam..more air and fuel sooner = mo power quicker sooner etc..you know the drill

Sounds like a great question for RMBuilder. I think I asked Bob a similar question, but cannot recall his exact answer. I'm pretty sure more overlap tends to move the power band higher in the RPM range, which would make sense when you look at the profiles of the drag racing style cams with small LSA of 108* and 109*, compared to the RV type cams that usually have 114* or more.

I agree, this would be a great topic for Bob!

+1

Most RV and towing cams are ground on a 114. Most drag race cams are on a 108-110. Most supercharger cams are also 112-114 because less boost gets pushed out the exhaust valve during overlap.

So why would a narrower LSA provide more low end torque? I'd like to know why.

114

114 hands down....but Bob is the man on this !!!!

Back to back dyno pulls I did, the 114 had less bottom and midrange than the 112, took 4 seconds longer to make the pull but carried the HP 200 RPM further. Same grind solid roller just different LSA.