The Hall-Scott A-7 was an early liquid-cooled aircraft engine manufactured by the Hall-Scott company of Berkeley, California. Using a straight-4 configuration, the engine developed 90 horsepower (67 kW) as the A-7 and 100 horsepower (75 kW) as the A-7a. In service these engines suffered from reliability problems and were prone to catch fire while in operation.
Variants
A-7: The A-7 used the same cylinders as the earlier Hall-Scott A-5. Bore: 5 in (127.00 mm), stroke: 7 in (177.80 mm), displacement: 549.78 cu in (9.01 L), weight: 410 lb (190 kg), power: 90 hp (67 kW) at 1,400 rpm, weight: 410 lb (190 kg)[1]
A-7a: The A-7a used the same cylinders as the earlier Hall-Scott A-5a. 100 hp (75 kW) 5.25 in × 7 in (133 mm × 178 mm)[1]