The cylinder heads are L-shaped combustion chambers allowing the valves to be actuated by direct contact with the cams eliminating rockers and rods.
The valves can be reground without removing the cylinders. The port pluga are unscrewed, and the valves can be removed through the ports.
Type: 7 cylinder radial, L-head, air cooled 4 stroke
Rating: 150 hp at 1900 rpm
Displacement: 612.15 cu.in
Compression ratio: 5-1
Bore: 4 1/2 in
Stroke: 5 1/2 in
Length: 35 in
Diameter: 36 in
Weight: 400 lb
Fuel consumption: not more than .56 lb/hp/hr
Oil consumption: not more than .023 lb/hp/hr
Lubrication: pressure system
Ignition: dual Scintlla
Carburation: Stromberg NAR-5A
Spark plugs: 2 per cylinder
All Aero 