i have heard different people say different things but i thought you guys would know more about it.

what does lsa do to the horsepower. from what i understand a tighter lsa will produce more horsepower. but i have also heard people say that they are going with 112 vs. 114 to keep the rpm's down. is this true too? that the tighter the lsa the quicker it will peak.


thanks for the info.

 

im sure you guys know something about this stuff. come on now, enlighten me!

 

check out a thread I started called "using LSA to adjust the powerband"

Rich explains all.

LSA should just "happen" as a result of propperly chosen cam events

 

A tighter Lobe separation means that the exhaust valve and intake
valve are both open for a longer period of time.

At low RPM or Idle, this will produce weak vacuum and poor idle
because the pistons are moving slower and cannot create a
low enough pressure area to suck in fuel/air mix.

For higher RPM, the tighter LSA will promote scavenging improving
volumetric efficiency. This of course only applies with properly tuned
intake, exhaust, etc.

 

seems to me that alot of people disagree on some of the effects of lsa.

 

Read all of that thread Trey started.

http://web.camaross.com/forums/showt...hreadid=120198

Rich's posts are very good.

In summary, when the engine designer chooses the intake and exhaust valve events to fit the engine's intended use and parts combinations, the LSA is what's left; it's not the place to start the cam design. IOW, it's a dependent variable.

 

if you want to "expierence" this first hand, try desktop dyno. I wouldn't trust it for accuracy of numbers (too many variables are missing for it to be accurate IMHO- but then again what do i know) but it seems to work well for cause and effect.

you also wont see a "durration" or "lsa" input anywhere. you will find a intake/exhuast opening closing and centerline input though further backing the "depenent" variable thoery


...maybe i should say experiment instead of expierence now that i think about it

 

Trey, go to the button called Cam Math to put duration numbers in