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How the Grail Engine Works


Grail Engine Design
Grail Engine Design
The Grail engine
The Grail engine
Courtesy of Grail Engine Technologies

At just 500 cubic centimeters, the Grail Engine is quite small -- about one-fourth the size of the engine on a typical economy car.

At first glance, the company's prototype looks like any ordinary two-stroke engine, until you notice the large, upward-facing intake valve coming off the center of the piston. That has an important function we'll explore in a bit -- the Grail Engine makes much more use of air pressure than a normal internal combustion engine. The engine is comprised of:

  • A cylinder and a piston
  • A single exhaust valve at the top of the cylinder that lets out exhaust gases after the combustion process is complete
  • Three spark plugs, also at the top of the cylinder. These create the "spark" that drives ignition (Most car engines have one spark plug per cylinder)
  • A "pre-compression chamber" that houses a reed valve, a component that keeps fresh air flowing into the engine in one direction (Reed valves are a common part on two-stroke engines)
  • A single intake valve, which draws in air and fuel, located inside the piston
  • Two vent-to-piston ports and two piston-intake-ports
  • A small crankcase that translates piston motion into wheel motion

[Source: Grail Engine Technologies]