These names, although sometimes dissociated, actually go together in the construction of the engine that receives these names.

-It is the motorcycle engine that Scottish emigrants built from 1921 to 1931. They were William and Thomas Henderson.

-These were motorcycles that were sold quickly when they went on the market, because they were big and powerful for the time.

“Henderson motorcycle”

-This motorcycle was known as the Henderson Four. And it was Heath who modified its engine and adapted it for aviation.

-This engine had four upright, in-line, air-cooled cylinders with a total displacement of 80 cu. in. and a power of 25 hp.

-The Heath Airplane Company modified it to install it on the Parasol airplane of the same brand.

“Heath Henderson on the Parasol”

-The Heath B-4 model as it was known, received the ATC E4-3 with a power of 25 hp at 2,800 rpm.

-Nevertheless, the manufacturer put it at 27 hp at the same revolutions and 30 hp at 3,000 rpm at takeoff

“Heath Henderson B-4”

-As a curiosity, it had Bosch magnetos, Zenith carburetor, Heath electric starter, BG spark plugs and Thompson valves.

-We have located a 1928 Heath Henderson with double ignition. Observe the two spark plugs in the cylinder head: one vertical and the other inclined.

“Heath-Henderson with double ignition”

“Heath-Henderson B-4 model”

-We have also received a B-4, although not very clear. It is from the year 1929.

-As we have received a double drawing of this engine, we will show it too. It is commented that the crankshafts used in motorcycles were weak for the new function.

“Heath-Henderson”

From Appendix 6: Almost mainly known by the Heath-Henderson compound name, the Heath engine was a conversion of the Henderson motorcycle engine. Located in the town of Niles, in Michigan.

-Let's see an advertisement for this brand.

“Heath-Henderson's ad number 22”

-Heath adapted engines for airplanes, boats, etc.

“Heat-Henderson installed” (AEHS)

-Among the adaptations or conversions, starting from the classic motorcycle engine, there was the double ignition, as we see next comparing the two engines, the normal and the double magneto one.

“Normal and with magneto”

“Heath-Henderson K model, rear view”

"Conversion of a Henderson, with different rocker covers"

"Conversion of Henderson with inverted cylinders for Air Racers, photo EAA"