26-11-2020, 09:46 PM
I thought it might be of interest to look at the other end of the scale, one of the earliest Austin Seven engines. This is a section from Encyclopaedia Britannica 14th edition Volume XII, Part 1 (1929):
Small Motor Car Engines
The "Baby Austin" Engine.—The performance of the modern tiny motors typified by recent Austin and Singer designs is so remarkable as to merit special notice. A section of a seven H.P. Austin small-car engine is given in fig. 15. The four en bloc cylinders of 2.2 in. bore and 3.0 in. stroke (see table) are fitted with a detachable head. The pistons are of aluminium alloy. The side-by-side valves are cam-operated in the usual manner. Lubrication is by a drowned oil-pump driven from the camshaft as indicated, and ignition is by H.T. magneto. Thermosyphon cooling with a "film" radiator and fan. The four-throw crankshaft is borne in two roller bearings. The mixture is supplied by a Zenith carburettor. The power output is: At Rev. per min. 1000, 1500, 2000, 2500, 2800 B.H.P: 3.8, 6.2, 8.7, 11.0, 12.0 (max.) This miniature engine propels its car containing three or four adults with ease at 35 miles per hour on an ordinary good road surface, with a petrol consumption of 40-50 miles per gallon.
Taking these BHP figures and calculating torque we get:
1000 RPM 20.0 lbs ft
1500 RPM 21.7 lbs ft
2000 RPM 22.8 lbs ft
2500 RPM 23.1 lbs ft (maximum torque)
2800 RPM 22.5 lbs ft
Small Motor Car Engines
The "Baby Austin" Engine.—The performance of the modern tiny motors typified by recent Austin and Singer designs is so remarkable as to merit special notice. A section of a seven H.P. Austin small-car engine is given in fig. 15. The four en bloc cylinders of 2.2 in. bore and 3.0 in. stroke (see table) are fitted with a detachable head. The pistons are of aluminium alloy. The side-by-side valves are cam-operated in the usual manner. Lubrication is by a drowned oil-pump driven from the camshaft as indicated, and ignition is by H.T. magneto. Thermosyphon cooling with a "film" radiator and fan. The four-throw crankshaft is borne in two roller bearings. The mixture is supplied by a Zenith carburettor. The power output is: At Rev. per min. 1000, 1500, 2000, 2500, 2800 B.H.P: 3.8, 6.2, 8.7, 11.0, 12.0 (max.) This miniature engine propels its car containing three or four adults with ease at 35 miles per hour on an ordinary good road surface, with a petrol consumption of 40-50 miles per gallon.
Taking these BHP figures and calculating torque we get:
1000 RPM 20.0 lbs ft
1500 RPM 21.7 lbs ft
2000 RPM 22.8 lbs ft
2500 RPM 23.1 lbs ft (maximum torque)
2800 RPM 22.5 lbs ft