Gamma Type Stirling Engines (updated 12/02/07)

Gamma Type Stirling Engines

Gamma type engines have a displacer and power piston, similar to Beta machines, however in different cylinders. This allows a convenient complete separation between the heat exchangers associated with the displacer cylinder and the compression and expansion work space associated with the piston. Thus they tend to have somewhat larger dead (or unswept) volumes than either the Alpha or Beta engines.

Furthermore during the expansion process some of the expansion must take place in the compression space leading to a reduction of specific power. Gamma engines are therefor used when the advantages of having separate cylinders outweigh the specific power disadvantage.

Because of the convenience of two cylinders in which only the piston has to be sealed, the gamma configuration is a favorite among modellers and hobbyists.

An amazing "heat of your hand" engine, the model MM-7 Stirling engine made by the American Stirling Company - will run on a temperature difference of only 4 degrees C! This is one of a number of innovative gamma type model Stirling engines that they describe on their website, including the model MM-1 Coffee cup engine and recently they have developed a delightful Stirling engine kit - the Eco Power. The DVD instructional video that comes with this kit shows you how to build it using a small hammer, pair of scissors, Scotch tape, sandpaper and glue - the most exotic tool required being a 1/16" Dremel drill..

The Fizgig by master modeller Mick Collins. This delightful engine comes with a complete set of drawings and instructions which can be downloaded from Mick Collins' website, together with performance characteristics, feedback from modellers who have built the engine, and other interesting information. (Note: this engine was recently withdrawn by Mick Collins, due to the unavailability of some key components. Fortunately Mick has some alternative interesting designs: the Piglet, Phoelix, Whippit and others.

Another approach is that of Boyette White, who converted a Briggs and Stratton engine into a Gamma type Stirling engine by adding the displacer and heat exchanger sections. Boyette's website is a delightful collection of model engines, with links to other related sites.

All Hot Air - an aptly named British company made this very nice Gamma type Stirling engine model called the "Super-Vee". Their web pages have unfortunately been discontinued, however I decided to keep the photograph in order to point out the excellent craftsmanship and beauty of this design.

The Little Engine Pages by Roy Rice and Richard Egge include some delightful Stirling engines by these two very innovative modellers. The engine shown is a water cooled Ringbom Stirling engine "Aquatap" made by Roy Rice. The Ringbom engine is a Gamma type engine in which the displacer piston is moved by pressure forces, and have no mechanical connection to the crankshaft.

Gamma Type Stirling Engines

Back to Alpha Engines, Beta Engines

Back to the Stirling Cycle Machines home page

	An amazing "heat of your hand" engine, the model MM-7 Stirling engine made by the American Stirling Company - will run on a temperature difference of only 4 degrees C! This is one of a number of innovative gamma type model Stirling engines that they describe on their website, including the model MM-1 Coffee cup engine and recently they have developed a delightful Stirling engine kit - the Eco Power. The DVD instructional video that comes with this kit shows you how to build it using a small hammer, pair of scissors, Scotch tape, sandpaper and glue - the most exotic tool required being a 1/16" Dremel drill..
The Fizgig by master modeller Mick Collins. This delightful engine comes with a complete set of drawings and instructions which can be downloaded from Mick Collins' website, together with performance characteristics, feedback from modellers who have built the engine, and other interesting information. (Note: this engine was recently withdrawn by Mick Collins, due to the unavailability of some key components. Fortunately Mick has some alternative interesting designs: the Piglet, Phoelix, Whippit and others.
	Another approach is that of Boyette White, who converted a Briggs and Stratton engine into a Gamma type Stirling engine by adding the displacer and heat exchanger sections. Boyette's website is a delightful collection of model engines, with links to other related sites.

All Hot Air - an aptly named British company made this very nice Gamma type Stirling engine model called the "Super-Vee". Their web pages have unfortunately been discontinued, however I decided to keep the photograph in order to point out the excellent craftsmanship and beauty of this design.
	The Little Engine Pages by Roy Rice and Richard Egge include some delightful Stirling engines by these two very innovative modellers. The engine shown is a water cooled Ringbom Stirling engine "Aquatap" made by Roy Rice. The Ringbom engine is a Gamma type engine in which the displacer piston is moved by pressure forces, and have no mechanical connection to the crankshaft.