Volume 5, Number 4     July/August 1997

  Technology Transfer

Composite Licensed for Pistons

ASA HAS GRANTED A GARDENA, CALIFORNIA company the first license to use a tough, space-age material to make high-performance pistons for internal combustion engines.

Other potential license applications could include oilless pistons for natural gas pumps; recreational vehicle engines for snowmobiles, motorcycles, hovercraft and jet-skis; and weight-critical applications like ultralight aircraft engines.

NASA granted Hitco Technologies exclusive rights to make, sell and use carbon-carbon pistons for high-performance automotive applications and co-exclusive rights for competition racing and small-to-large-bore diesel engines in the U.S. and certain foreign countries. The company intends to develop and manufacture the pistons at its Gardena factory.

Heat Resistant Material for High Performance Piston

Carbon-carbon pistons are significantly lighter than aluminum and steel pistons. In addition, their thermal expansion is significantly lower. Because of these attributes, they offer improved performance over their aluminum and steel counterparts. They also offer some potential for reducing emissions, if used in conjunction with carbon-carbon cylinder liners or carbon-carbon cylinder blocks. Pistons used in high-performance internal combustion engines usually are made of an aluminum alloy. The strength and stiffness of aluminum alloys decrease rapidly as temperatures rise above 350° Fahrenheit. Aluminum alloys melt at approximately 1,100° Fahrenheit while carbon-carbon does not melt and fully retains its room-temperature strength to temperatures well above 3000° Fahrenheit.

The material originally was developed in the 1960's for high-strength heat shields for strategic missile applications. It is widely used today for brakes in aircraft, clutches in Formula One and Indy race cars and for military and aerospace applications like the nose cap or wing leading edges of the Space Shuttle.

Langley Research Center researchers successfully tested prototype pistons in gasoline and diesel engines and have patented a number of concepts relating to carbon-carbon pistons for internal combustion engines.

"Carbon-carbon is the material of choice for the most demanding applications," said Burton Northam of Langley's Environmental Interactions Branch and a carbon-carbon piston researcher. Northam worked with Langley researchers Philip Ransone, Kevin Rivers and Philip Glaude in carrying on the pioneering work Langley's Allan Taylor began in the mid-1980s.

Langley's Technology Applications Group is seeking additional licensing partners for carbon-carbon piston technology and related technologies for cylinder liners, exhaust manifolds, engine valves, turbo-charger housings and rotary engine components.

For more information, contact Rosa Webster at Langley Research Center.
Call 757/864-3493 E-mail: r.c.webster@larc.nasa.gov

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