In Reply to: VTEC is much better? no way! posted by Ming on June 11, 1999 at 15:58:45:
Neither system works like the F1 engines, with a continuously variable cam profile. VANOS merely advances the cam timing. The profile (lift and duration) is static. It works by rotating the cam with respect to the timing gear at the end of the cam. VTEC has separate cam profiles on a single cam. The actuator at the end pushes the cam back or forward to engage the selected profile.
While VANOS can advance the timing in a continuously variable fashion, it does nothing for lift and duration. VTEC, while only being able to offer 2-3 profiles (that's the most I'm aware of), does change to a more radical profile at the higher end.
So, while your statement is correct that VANOS is continuous and VTEC only changes at certain RPM, it is completely orthoganol to the situation being discussed. You don't work at Microsoft by any chance, do you?
Me, I want my F1 infinitely adjustable valve timing. Having to refill the liquid nitrogen every 1 or so would be annoying, though...
: : VANOS just alters cam timing.... VTECH actually changes lift and duration.
: : Shawn
: VANOS can change continuously..
: but VTEC can only change at certain RPM (ON/OFF at certain RPM)