What real difference does the lsa on a cam make?

I've also read the Comp Cams site about all of this......I gotta say, I firmly believe they got a lot of it WRONG. Most of what they have on it is completely backwards.

Simply

Without going into any overlap discussion.....

IF you move your intake lobe closer to the EX, you are closing the intake valve sooner into the compression stroke. (think cam advance) This creates less compression bleed off at low RPM. Moving the lobes closer together, means the EX is open longer into the intake, at lower RPM, this makes for a rich exhaust small, and a bit of rough idle, (think two stroke) because you are using the exhaust to pull intake charge, but the EX and intake charge is not moving fast enough to work as designed. However, in small cams, (like here) moving the EX lobe closer to the intake, other than a rich(ish) rough (ish) idle, will make more low end torque (providing you're not talking about 850RPM) because the power band, comes in harder, quicker. (building more cylinder pressure, because there is not as much compression bleed off through the intake valve.

Of course, 250* duration 600 lift cams follow a totally different set of rules.


And I swear, if people put more cams in motors and less time playing with desktop dyno.........

My dyno, for my engine power theories, is pickup trucks, with stock converters, and 727's, pulling 10,000+ in steep hills, and yes, there is a difference.