Argus 70 hp

Argus Motoren

Industry	Aircraft engine manufacturing
Founded	before 1911
Headquarters	Germany
Products	Aircraft engines (including Argus 70 hp)

The Argus 70 hp aircraft powerplant, also referred to as the Argus Type I—a designation shared with the Argus 50 hp but distinct from the As I model—was introduced around 1911 as a four-cylinder, water-cooled inline engine produced by the German manufacturer Argus Motoren. This engine was also manufactured under license in France by Automobiles Rossel and marketed there under the names 'Aviatik' and 'Aviatic-Rossel' through Louis Clément, who served as the regional sales agent for Automobil und Aviatik AG.

Design and development

With a bore and stroke of 124 mm × 130 mm (4.9 in × 5.1 in), the Argus 70 hp delivered an output of 70 hp (52 kW) at 1,250 rpm. Its design was an advancement of the previous Argus 50 hp model, retaining identical bore and stroke dimensions but introducing overhead valves in place of the earlier side-valve configuration. Documentation from a 1911 brochure by Automobil und Aviatik AG already lists this engine variant.

The cylinders were cast from iron in pairs, incorporating integral cooling jackets within each casting. Each cylinder featured two overhead valves actuated by pushrods and rocker arms connected to a camshaft positioned on the engine’s left side. Intake valves were arranged towards the center between paired cylinders, with their intake passages merged into a single external port facing left. An intake manifold made of cast aluminum housed a single Cudell-G.A. carburettor.

Constructed from aluminum, the crankcase consisted of separate upper and lower halves; the lower section included four mounting arms cast directly into it. Each pair of cylinders was secured to the crankcase using six bolts. The crankshaft was supported by two ball bearings at its ends and one plain bearing located centrally.

The camshaft received its drive via spur gears connected to the crankshaft at the control end. Ignition was provided by one or two spark plugs per cylinder, powered by a single Bosch magneto mounted on the control side and driven through an intermediate spur gear from the crankshaft. Lubrication relied exclusively on splash lubrication, as no oil pump was fitted. Coolant circulation was maintained by a centrifugal water pump driven off the camshaft gear on the carburettor side.

In October 1911, this engine underwent evaluation during a French aviation engine competition, where it achieved an average output of 72.2 hp (53.8 kW) at 1,248 rpm. The following year, it participated in the Kaiserpreis contest for aircraft engines, delivering an average of 72 hp (54 kW) at 1,342 rpm.

Applications

• Friedrichshafen FF.4
• Friedrichshafen FF.8