What s more, the system can recover much of the horsepower lost in normally aspirated engines by operating on the lean side when manifold pressure is limited by altitude. Another side benefit is that if unleaded fuels become mandated, Prism simply adjusts the timing to allow the engine to run on whatever is in the tanks while still guaranteeing detonation protection. Prism will be powered by the GAMI Supplenator, a self-exciting minialternator that will mount on one of the vacated magneto pads on the engine. The aircraft s electrical system becomes the backup system. A side benefit of this setup is that the Supplenator will have enough surplus power to run both Prism and take over some of the aircraft s load in the event that the ship s power fails.
Prism has the potential to increase engine life by keeping peak cylinder pressures at bay.
Prism will appeal to those pilots who don t want to lose the freedom to operate their engines at a seemingly infinite combination of power settings. A two-cylinder test engine logged hundreds of hours under the control of Prism. GAMI is pushing for joint certification of Prism and the ability for Prism-controlled engines to use 100LL and 100LL with the lead additives removed, which is capable of about 91 to 92 octane. The advantage to the no-lead 100LL is that it is already compatible with rubber fuel system components. If all goes well, certification could come by the second quarter of 2001.