PORT AREA

Modern Formulae 1 engine operates at high speed (approx 20,000 rpm), enabled by exotic lightweight reciprocating components and pneumatically sprung valve operating system. The required air flow is achieved through large intake valves requiring a suitably large cylinder bore. In conventioanal high performance  4 valve engines, intake valve flow area is a limiting factor in engine performance. Intake valve area limit of approx 32% of bore area is a basic geometric limitation( 2 x intake valves, each limited in diameter to about 40% of the Bore), with the available air flow area being significantly

smaller than the valve head area, at typically less than (30% bore area). The inlet flow area potential of the Duke engine is approx 25% greater than that of a current Formula 1 engine of similar bore. In the key areas of intake port area and maximum valve/port operating speed, the Duke engine is just not limited to the same extent as conventional engines. In current V3 and V3i versions of the Duke engine port area is less than the potential, limited by legacy architecture. Also while the speed limits of the V3 was around 3500 rpm, the V3i target using revised architecture is 6000 rpm. Hence while the V3 power is 105kW, the V3i target power is “only” 137kw

THROTTLE RESPONSE

The reduced crank mass also possesses reduced rotational kinetic energy compared to conventional crankshafts and the cylinder block, pistons, and reciprocator spin (in the 5 cylinder engine) at only 1/5th of crank speed. Overall, total rotational kinetic energy is lower than for the equivalent internal combustion engine, meaning there is less resistance to acceleration and deceleration of the engine. The engine therefore has a very quick throttle response.While the naturally aspirated performance prospects of the Duke engine are excellent, pressure charging is also attractive. In most respects the Duke engine could be expected to respond to pressure charging in ways similar to a conventional engine. The demonstrated detonation resistence of the Duke engine offers the prospect of maintaining higher compression ratios with high boost pressures in highly rated SI engines.

The Axial arrangement of the Duke engine also lends itself to variable compression ratio, improving the full load power/partload efficiency trade off typically encountered in fixed compression ratio, highly pressure charged engines.