quote:
Originally posted by Jake:
... Said we were giving up some low end power with the 114 deg lobe separation angle ...
I strongly disagree with him because your motor is a Big Valve motor. I'll guarantee you he's wrong. With the big intake valve, and canted valve geometry the effects of overlap are amplified. You want to minimize overlap to optimize low rpm power, improve drivability, improve vacuum at idle. The lobes were chosen based on 114 degree LSA, and the way they interact at top dead center, in the overlap period. The lobes are pushing the limits for the boundaries I established. As far as I'm concerned, 112 degree LSA screws that up a bit. It will still work, but not the way he's telling you it will work. Expect drivability and low rpm power to be worse, not better.
Wider LSA results in opening the exhaust valve earlier which also improves high rpm over-rev when mufflers are involved. This is why they say narrow LSA cams put more demand on the exhaust system, i.e. the system must be better designed and have low back pressure.