RD 24v DOHC Head

[Borat]

they also have different goals.. honda's is mainly for fuel efficiency, BMW designed theirs for a flat torque curve as well as fuel efficiency..

They also work slightly differently, Vtec has a 2nd cam profile that comes in at a certain rpm where the BMW and most other manufacturers have a single cam profile that is either advanced or retarded.

Jordan- sorry but was you post just taking the piss? I thought honda had Vtec long before VANOS?

[fabianyee]

the VTEC cams actually has 3 cam lobes for each cylinder...
the outer 2 lobes are with normal degree and lift(directly over the valve lifters)...
The center lobe has more aggressive angle and higher lift. and activated at the higher RPM after the VTEC switchover point.
This is what I observed from an actual engine with the valve cover removed. Not too sure whether it advance and retard the camshaft like the VANOS.
The MIVEC system on the Mitsubishi works on the same principle as the VTEC but with 2 cam lobes instead on 3 on the VTEC.