So the Grail Engine has a very efficient form of internal combustion. It's lightweight, inexpensive, and produces a lot of power for its size. As we said earlier, the 500 cc prototype can produce 100 horsepower while getting 100 miles per gallon (42.5 kilometers per liter). But what else can it do?
Riley said the Grail Engine eliminates many of the drawbacks normally seen on a typical two-stroke engine. For one, oil and fuel never mix together here, so it doesn't have a smoke problem. It's also very quiet and low on vibrations, he said.
Because the engine has fresh, compressed air moving through it at all times, it has no problem staying cool. The ability to keep the combustion chamber uniformly cool is what helps make FS-HCCI possible, Riley said. This increases thermal efficiency and cuts down on nitrogen oxide emissions. Also, it's not just limited to a single cylinder. The Grail Engine is modular in design, so several could be strung together to create a multi-cylinder engine [source: Wojdyla].
But as Riley likes to say, "Wait -- it gets better." The Grail Engine is designed to run on virtually any type of fuel, including gasoline, propane, diesel and natural gas. It can also carry more than one type of fuel at once in separate tanks. The engine can do so because an onboard computer can adjust its compression ratio on the fly, adjusting the motor accordingly whenever the driver wants to use a different fuel.
Also, its design prevents the contamination of hydrogen currently seen on fuel cell cars, making that type of fuel more feasible than ever. "This puts fuel cells into a whole new light," Riley said.