A Wallace L-S engine is on display at the San Diego Museum in California.

From Appendix 6: The Wallace engine mentioned in the main text, which was located at the San Diego Museum, was photographed during a visit and is shown below. Model L-S.

“Two Views of the Wallace engine”

-As described on the panel, it is an inverted, two-stroke, supercharged, inline three-cylinder engine with rotary valves.

-It was designed in 1929, and it was the first engine to achieve 1 HP per cubic inch of displacement.

-More specifically, it produced 125 HP at 3,600 rpm with only 120 cubic inches of displacement.

-It required a reduction gear so that at that maximum speed, the propeller rotated at 1,800 rpm. That is, 2 to 1.