2-stroke engines, designed at the Royal Aircraft Establishment (RAE) by research engineer C. F. Caunter.

-The "B" model was a 4-cylinder, upright, in line, air-cooled engine with a displacement of 500 cc. per cylinder.

"Caunter, B"

-The "C" had also 4 cylinders, but inverted. It had a displacement of 2.3 liters.

-Another Caunter engine with 3 inverted cylinders in line had 1.9 l. of displacement. All engines drove puller propellers.

"Caunter, C"

-In the text appears the B model running, now we show it stopped without the propeller.

"Caunter Modelo B"

-They also made radial engines like the following five-cylinder. It seems that they made three- and seven-cylinder engines with the same type of cylinders. All of them were two-stroke.

"Caunter 5-cylinder engine"

-The three-cylinder gave 38 hp. The five-cylinder, delivered 68 hp and the 7-cylinder reached 85 hp.

-Another view of the Caunter 5-cylinder radial that gave 60 hp.

"Caunter, front view"

-From appendix 7: Another view of the Caunter Type C on the carburetor side.

"Caunter C four-cylinder"

From Appendix 10: We have some more details of the Caunter two-stroke, 5-cylinder radial designed by C. F. Caunter.

"View of the 5-cylinder Caunter engine"

-The interesting thing about the Caunter solution is that because of the two-stroke cycle, the pistons have two different areas or diameters. The bigger one in the lower part will create a pressure sufficient to introduce the mixture in the top of the piston and fill and sweep the cylinders.

"Another Caunter engine front view"

-The ducts that transfer the mixture from the bottom to the top are clearly seen in the first picture: they are double white bends next to the exhaust ports that are black rectangular tubes that go towards the periphery of the engine.

"Characteristic piston shape. See the deflector."

-Factory picture for this engine designed by an engineer of Royal Establishment.