Siemens-Halske 9 / Sh 12
The Siemens-Halske Sh 12 was a nine-cylinder, air-cooled, radial engine for aircraft built in Germany in the 1920s. First run in 1925, it was rated at 80 kW (110 hp).
The Sh 12 is low pressure due to the engine being completely ball bearing. Cylinders are of steel barrel with aluminium alloy heads screwed and shrunk on, and also locked by special nut and counter ring. The intake and exhaust ports are on side.
The crankshaft assembly is composed of two major castings and front and rear cover plates all of aluminium alloy. The crankshaft is two piece single throw.
All connecting rods are tubular. The master rod is on two ball bearings. Aluminium alloy pistons have two compression rings and two oil rings on each pistion. The exhaust and intake valves are tulip shaped.
Accessories available at extra ost were exhaust manifold and Bosch electric starter.
Type: 9 cylinder air cooled radial
Dept Commerce Approved Certificate
Military Rating: 128 hp at 1736 rpm
Commercial Rating: 128 hp at 1736 rpm
Displacement: 517 cu.in
Compression ratio: 5.3-1
Bore: 3.937 in
Stroke: 4.724 in
Length: 32 in
Diameter: 40 1/2 in
Weight: 382 lb dry
Fuel consumption: not more than .53 lb/hp/hr
Oil consumption: not more than .027 lb/hp/hr
Lubrication: Dry sump, forced feed, low pressure
Ignition: 2 Siemens Magnetos
Carburation: 2 Sum carburetters
Spark plugs: 2 per cylinder