A 140 hp 7 radial, it later evolved into the Jacobs LA-1. The ACE featured permanent mould cast aluminium cylinder heads, bolted to a forged dteel barrel with 12 nickel steel bolts and nuts. The rocker arm system was open for valve and valve spring cooling.
High tungsten-Vanadium inlet valves – C.N.S. special exhaust valves. All shafts had ball bearings. All aluminium castings are heat treated alloys.
Pistons are aluminium alloy heat treated, with special ribbing. Fuel floating pins are fitted with aluminium alloy plugs.
The carburettor has controllable air heater.
The ACE LA-1 received ATC 31 circa 1920s.
Type: 7 cylinder air cooled radial
Rating: 140 hp at 1800 rpm
Displacement: 528.5 cu.in
Compression ratio: 4.7-1
Bore: 4.5 in
Stroke: 4.75 in
Diameter: 33 in
Weight: 375 lb
Fuel consumption: not more than .55 lb/hp/hr
Oil consumption: not more than .017 lb/hp/hr
Lubrication: 1 pressure pump; 2 scavenger pumps
Ignition: 2 Scintilla
Carburation: NAR-5 Stromberg
Spark plugs: 2 pr cylinder