FWIW, I found the following on a Honda oriented site which refers to a butterfly
valve that opens in the intake to decrease its intake runner length at higher rpms...
VTEC = Variable Timing Electronic Control...it is an electronic hydraulic actuator on
DOHC honda 4 cylinder engine that varies cam profile and intake runner distance by
opening secondary butterfly valves above 5500 RPMs to decrease runner path length.
This archive was generated by hypermail 2b29 : Fri Jun 20 2003 - 11:54:41 EDT