External Combustion Engine Piques Interest at SAEExternal Combustion Engine Piques Interest at SAE

DETROIT, MI -- The buzz at the SAE 2008 World Congress here was over a water-lubricated external combustion engine that uses steam to power automobiles, lawn mowers and stationary generators.

Known as the Cyclone engine, the product drew hundreds of curious engineers to the Cyclone Power Technologies booth at Cobo Hall. Harry Schoell, company CEO and inventor of the engine told visitors the Cyclone is cleaner than conventional internal combustion engines and added it doesn’t need a transmission, clutches, mufflers or catalytic converters.

“We have no doubt that this is the right technology for the automotive industry,” Schoell said. “They’ve been trying to clean up the internal combustion engine for 50 years, and it’s still dirty.”

Schoell said his engine works by burning fuel in an external combustion chamber and sending its hot gases through three heat exchangers. The first of those three heat exchangers heats water to 1,100-1,200 deg F and raises the water’s pressure to 3,200 psi. The superheated water is subsequently injected into the cylinders where it expands by a factor of approximately 1,800, therefore generating rotary motion.

Schoell added the engine is able to use water for lubrication because it has no metal-to-metal bearings.

At the show, the company demonstrated a 100-hp version of the engine that weighed just 35 lbs. Schoell said the automotive version of the engine uses six cylinders. A version for lawnmowers employs a single cylinder, while a model designed for stationary power uses two cylinders.

Schoell declined to discuss the engine’s sealing techniques, saying the sealing technology is proprietary. Engineers at the company’s booth expressed concern about sealing, however, at least in part because the well-known Wankel rotary engine struggled with apex seal technology for many years.

Cyclone has been demonstrating its technology for industry engineers since the engine won an SAE Tech Award in 2006. No automakers have announced plans to put the engine into production, however.

Phil Myers, president of Advent Power Systems, Inc., said his company has become a licensee of the Cyclone technology because he sees it as a long-term replacement for the internal combustion engine and the diesel.

“We’re not going to make it successful overnight,” Myers said. “But in the long term – maybe ten or 20 years – we hope to get a significant market share.”