A Variable Timing Electonically Controlled High Pressure Injection System for 2T S.I. Engines

Following general remarks about high pressure direct injection systems impact on two stroke S.I. engine applications, further advantages, both on emissions as well as fuel consumption, obtainable with a variable timing injection system are presented.

An exhaustive evaluation, carried out on a single cylinder air cooled engine, clearly shows that sensible reductions, basically in HC emissions as well as in fuel consumptions can be obtained delaying the injection beginning depending on RPM and engine load. Further advantages appear available at idle, injecting every other cycle, if a suitably conceived system is adopted.

Finally an electronically controlled high Pressure injection system, derived from a low cost and dependable solution for small engines is proposed.