The Stelzer engine is a

two-stroke A two-stroke (or two-stroke cycle) engine is a type of internal combustion engine that completes a power cycle with two strokes (up and down movements) of the piston during one power cycle, this power cycle being completed in one revolution of ...

opposing-piston

free-piston engine A free-piston engine is a linear, 'crankless' internal combustion engine, in which the piston motion is not controlled by a crankshaft but determined by the interaction of forces from the combustion chamber gases, a rebound device (e.g., a piston ...

design proposed by Frank Stelzer. It uses conjoined

piston A piston is a component of reciprocating engines, reciprocating pumps, gas compressors, hydraulic cylinders and pneumatic cylinders, among other similar mechanisms. It is the moving component that is contained by a cylinder and is made gas-t ...

s in a push-pull arrangement which allows for fewer moving parts and simplified manufacturing. An engine of the same design appeared on the cover of the February 1969 issue of

Mechanix Illustrated ''Mechanix Illustrated'' was an American printed magazine that was originally published by Fawcett Publications. Its title was founded in 1928 to compete against the older ''Popular Science'' and ''Popular Mechanics''. Billed as "The How-To-Do M ...

magazine.

Operation

There are two

combustion chamber A combustion chamber is part of an internal combustion engine in which the fuel/air mix is burned. For steam engines, the term has also been used for an extension of the firebox which is used to allow a more complete combustion process. Intern ...

s and a central precompression chamber. Control of the air flow between the precompression chamber and the combustion chambers is made by stepped piston rods.

Applications

Applications envisaged for the engine include driving: * An

air compressor An air compressor is a pneumatic device that converts power (using an electric motor, diesel or gasoline engine, etc.) into potential energy stored in pressurized air (i.e., compressed air). By one of several methods, an air compressor forces m ...

* A

hydraulic pump Hydraulic pumps are used in hydraulic drive systems and can be hydrostatic or hydrodynamic. A hydraulic pump is a mechanical source of power that converts mechanical power into hydraulic energy ( hydrostatic energy i.e. flow, pressure). It genera ...

* A linear generator

Prototypes

A prototype engine was demonstrated in

Frankfurt Frankfurt, officially Frankfurt am Main (; Hessian: , " Frank ford on the Main"), is the most populous city in the German state of Hesse. Its 791,000 inhabitants as of 2022 make it the fifth-most populous city in Germany. Located on it ...

in 1983 and

Opel Opel Automobile GmbH (), usually shortened to Opel, is a German automobile manufacturer which has been a subsidiary of Stellantis since 16 January 2021. It was owned by the American automaker General Motors from 1929 until 2017 and the PSA Grou ...

was reported to be interested in it. In 1982, the Government of Ireland agreed to pay half the cost of a factory at

Shannon Airport Shannon Airport ( ga, Aerfort na Sionainne) is an international airport located in County Clare in the Republic of Ireland. It is adjacent to the Shannon Estuary and lies halfway between Ennis and Limerick. The airport is the third busiest ai ...

to manufacture the engines. A prototype car with a Stelzer engine and electric transmission was shown at a German motor show in 1983.Popular Mechanics, March 1984
/ref>

References

External links

* -- ''Two-Stroke Internal Combustion Engine 1983''
Diagrams of Stelzer engine and linear alternator
Proposed engines Free-piston engines {{Mech-engineering-stub

Operation

Applications

Prototypes

See also

References

External links