has quite a history. Located in the town of Hirtenberg south
of Vienna, Austria, HP's primary business as an ammunition
factory dates back to 1860. The word Patrone in their
name means cartridge.
HP produced hand made hunting cartridges but steadily expanded
to manufacture a full range of ammunition.
peak, during the Austro-Hungarian monarchy, the factory employed
over 4000 workers.
one million cartridges per day were being manufactured to
supply the axis powers. However, following World War II and
the postwar occupation period, the factory was left an empty
ruin until 1955. Production recommenced during 1957 under
the guidance of the former president, Fritz Mandl.
his interest, the model engine department was started in the
early 1960's to develop a twin cylinder military drone engine.
Then development of a .15 and .61 engine for the consumer
market followed. Only the .61 went into full production.
model of the .61 had a bell type rear rotary valve and Schnuerle
porting design, both were unheard features of in the 1960's.
Soon the .61 evolved into a front intake version which proved
to be more suitable for conventional model airplanes.
the success of the .61, the HP .40 soon followed and gained
a wide following which its descendant today still carries.
the 1970's a full line of engines soon to be known as the
most advanced and highest quality were in full production.
early 1980's the Austrian government took ownership of the
munitions factory. During this time development began on a
series of 4 stroke engines with a unique rotary valve design.
These proved to be the quietest and most fuel efficient engines
the late 1980's the engine production was neglected as it
was such a small portion of Hp's business.
after years of negotiation, RJL was able to purchase the model
engine department from Hirtenberger and move the engine production
to Southern California.
AG, Austria is still in the business of manufacturing ammunition
and munitions and is no longer affiliated with the model engine
engine line, name and HP logo were obtained in 1990 from Hirtenberger
AG, Austria. HP model engines are no longer associated
with Hirtenberger Patronen munitions company in Austria.