Internal combustion engine with multiple intake valves and variable valve actuation and timing

Abstract

A four-stroke cycle reciprocating internal combustion engine includes a piston mounted for reciprocal movement within a power cylinder and primary and secondary intake valves. The primary valve has a fixed event, in terms of both duration and lift, and the secondary valve has variable duration and lift. Although the timing of the primary and secondary valve events may be retarded from a standard timing value, both valves close at the same time regardless of the presence of timing retard. The dual event strategy, combined with camshaft timing retard for part load conditions, produces excellent charge motion by staggering the respective lifted flow areas of the primary and secondary valve events and by delaying the secondary valve opening.

Dependencies are inferred from the claim text.