(See Aeronca, Aeronca-Jap y Aeronco)

J.A. Prestwick & Company Ltd. (JAP) in London was an English motorcycle manufacturer that was founded by engineer J.A. Prestwick in 1895 and in the city of Tottenham.

-In 1907 appeared their first aviation engine, a two-cylinder 9 HP V-engine. It was heavy and had little power.

-The next one came out in 1909, a 4-cylinder engine with the V at 90°. It was air cooled and had intake valves and exhaust ports. Its power was 20 hp.

“20 HP”

-They made engines with 30 hp and 35/40 hp (the latter for the V8).

-Later they went over to the formula of horizontally-opposed cylinders like the 38 hp, or the J-99 with 36 hp by Aeronca-JAP (the E-113C). These engines were extensively used in the UK.

-They were built in the years 1936 to 1940.

From Appendix 6: A four-cylinder JAP engine with an output of 20 hp appears in an Italian publication.

-Possibly this is an adapted car engine by J.A Prestwick.

“JAP on an AVRO”

-As we see, it is an Avro triplane, used in the Italian Air Force, according to the information collected from the magazine.

-JAP was founded by J.A. Prestwick in 1895 and in the city of Tottenham.

-They were known for the manufacture of cinematographic projectors and internal combustion engines. Before the JAP Aeronca engines, they made the upright V4, which was built in 1910, and gave 35 hp.

-One of these engines was installed on the Australian plane built by Lawrence Marshall, and flew in 1912. It is possible that the engine is exposed at the "Australian National Air Museum" in Moorabbin.

“Aeronautic JAP V4”

-The engines were constructed by J.A. Prestwick (JAP), who founded the company in 1895.

-The company was integrated into the Villiers Eng. Company in 1965. But during WWII both already collaborated.

From Appendix 7: Motorcycle manufacturer who also intervened in the development of aviation engines. First, its clients were adapting the simple two-cylinder V-engines that were used on many airplanes.

“Two examples of adapted JAP motorcycle engines” (PiP)

-The motorcycle engines they used were between 6 and 16 hp.

-He also made four-cylinder engines that gave 20 hp, and the next one was the 8-cylinder V-engine with a power of 35 hp.

“JAP V8 engine”

“JAP V8 on a Bleriot type plane” (PiP-fmr)

Now we have some more information on the JAP-99, mentioned in the main text, from a British museum. It is an engine with two horizontally-opposed cylinders.

“J.99, cutaway”

“Appearance of the J.99 in a refined Cygnet”

"J.99, angled front and rear view - without magnetos - ”

From Appendix 9: We located two new images for the air-cooled V-8.

“JAP V-8, schematic drawing"

“Nice photo of JAP's V-8”

-An ad taken from the Aviation Ancestry blog about the JAP V8 engine.

“JAP ad”