The <<ALGOL>> type 120 supercharged, geared motor is derived directly from the ALGOL 9-cylinder radial engine, whose robustness and safety qualities are universally known.

The main difference between these two engines is the addition on the Algol 120 of a multi-fueled supercharger restoring power to 3,000 m. altitude and a propeller speed reducer.

On the other hand, the geared ALGOL with supercharger comprises a single power take-off of accessory controls by a shaft integral with the crankshaft and passing inside the hub of the supercharger turbine.

Cylinders. - The 9 cylinders arranged as a radial around the housing are made of special steel. Each cylinder has a fixing flange whose lower part fits into the housing. Large surface fins in the mass of the cylinder provide cooling. The light metal cylinder head screwed to the top of the cylinder is held at its base by a special steel hoop.

Special bronze valve guides are returned in intake and exhaust pipes. High-strength steel rings form a valve seat and are screwed to the bottom of the cylinder head.

The cylinder head holes receiving the 2 spark plugs, the starter valve, the intake and exhaust pipes are ringed in resistant bronze allowing easy dismantling of these parts and avoiding premature wear of the threads.

Motor coupling. - It consists of a one piece master rod with double section T and 8 rods hinged around the connecting rod.

The connecting rods and linkages are provided with a special bronze ring which is fitted hard on the connecting rod linkage, and free on the piston pin.

Crank shaft. - The high-strength steel crankshaft is in two parts allowing the assembly of the master rod in one piece.

Its assembly in its middle part is realized by a cone fit wedged and blocked by nut, thus ensuring a robustness and a rigidity perfect.

It has a single elbow and 2 bearings resting on roller bearings. It drives by its front end the crown of the reducer. It is statically and dynamically balanced by steel masses added to the arms. The rear bearing has in its interior a toothing for driving the shaft of the accessory controls.

Distribution. - The distribution is carried out by a double-row cam plate (intake and exhaust) driven by an epicyclic gear train. The cams control the valves by means of pushers each provided with a roller and connected to the rockers by rigid rods.

Lubrication. - The engine is lubricated under pressure by a gear pump attached to the rear of the engine and controlled by a pinion mounted at the end of the shaft of the accessory controls.

Carburetor. - The engine is powered by a a carburetor <<BRONZAVIA>> type 95 L I with intake regulator, placed vertically at the rear of the engine and warmed by a constant flow of oil. The latter from the sump is sucked by the pump and discharged into a pipe going to the carburetor. This tubing is provided at its lower part with a bypass charged to drive the excess oil towards the radiator. The oil leaving the carburetor passes into the lower part of the bypass and thus returns to the radiator.

Valves. - The valves are made of special steel with 2 seats screwed into the bottom of the cylinder head (intake and exhaust). The exhaust valve is specially machined and has a chemical cooling system.

The end of the valves is provided with a cemented steel grain on which the rocker arms are attacked (struck?).

Admission. - The intake manifolds are equipped with anti-flame designed to prevent, in case of return, any bursting of these pipes or the compressor housing.

Gearbox. - The engine is equipped at the front (propeller side) with a gearbox and planetary gear to reduce the speed of rotation of the propeller in a ratio of 11/17.

The gears of the gearbox are all cylindrical toothing and parallel axes. The play of these gears is defined in the manufacture and no adjustment is necessary to ensure the perfect distribution of efforts. The loads on the teeth and the axes subject to wear are very low. The robust and indeformable propeller shaft supports the axes of the satellites.

The position of these axes and their equidistant distribution on a circumference rigorously concentric with the crown and the fixed gear are made mechanically and can be controlled very easily. The friction parts are constituted by roller bearings whose wear is insignificant.

The replacement of various parts is easy and does not require adjustment operations themselves.

The assembly of all the parts of the gearbox is concentric with the crankshaft, which makes it possible to realize the good operation of the assembly before the putting into service.

The engine is provided with its exhaust hood and exhaust manifold at the front around the gearbox housing.

Supercharger. - The control of the supercharger turbine is equipped with a spring damper, torque limiter, and the satellites are equipped with small flyweights acting by centrifugal force. The multiplication ratio is 1 / 8.66.