What real difference does the lsa on a cam make?

StrokerScamp said
I assure you, that is not correct. By both experience as well as computer simulation, I have seen otherwise. A 114 LSA compared to a 108 LSA all things equal makes more torque down low on the desktop dyno every single time....without fail. In fact, it's usually a huge difference. The reason for that is because cylinder pressure bleed off is also RPM dependant. The more RPM, the more cylinder bleed off. A wide LAS will build more cylinder pressure down low in the RPM range. They also generally build more pressure in lower compression (under 9:1) engines. I don't know the whys and wherefores, but that much is true. I have verified it in person with a compression gauge many times. The narrow LSA does indeed take away from bottom end torque.

It's hard to say "always" and "never" in these cases. The LSA can be moved by affecting both lobes equally, or each lobe can be moved independant of the other, either advanced or retarded.

RockerDude - there is so much in cam science that the short answer is yes, it can greatly affect power. But in what way, and to what degree, is entirely a matter for conjecture until you have every detail on your specific engine worked out. Talk to your grinder once they have the cam and can tell you what the limits are, and then work with them on it. I like cams with LSAs of anywhere from 108 to 114. If you plan a small NO2 shot, pick a cam based on NA performance. For what you list, I'd like something in the 112-110LSA range.