Question

Which system can change both the phase and duration of the valve event?

(a) Profile switching system

(b) Phase changing system

(c) Variable event-timing system

(d) Variable lift system

This question was posed to me in an interview.

The above asked question is from Variable Valve Timing in division Valve Timing Technologies of Automotive Engine Design

Answer 1

Correct choice is (d) Variable lift system

To explain: Variable event-timing system can change both the phase and duration of the valve events and can be optimized at different engine speeds and load conditions.