Initials used by J.P. Gregoire (see Gregoire) who already owned a car-building factory with this name.

-He made some 4-cylinder aviation engines that were tested on several airplanes around 1910/11, especially monoplanes.

“GYP, Gregoire”

-At the MAE, the inverted engine is exhibited. It appeared in 1910 in the mentioned position. There is another one in New Zealand.

-The cylinders were casted in a block and enclosed in a sheet metal box that contained the cooling water.

-A characteristic of this engine was the arrangement of the water radiators, without a pump for forced circulation, since it works through the water temperature difference: hot water ascended through the tubes (see Gregoire) and became cool again.

-This process is sometimes called "thermosiphon".

-In the illustration we have the treated engine. There were several powers, but this time with an oil tank -see the operation of the grease pump in the front-.

-The tank is located under the engine, however there are no water radiators in the upper part of the engine.

“GYP cylinders”