Outside the box: the rotary motor of Walter Macomber

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When there’s talk about rotary engines these days, it's usually about Wankel engines, which were designed by Felix Wankel and have been seen in production cars from 1964 onwards. As a matter of fact, keen Wankel engine proponents Mazda Motors (the only manufacturer still using them?) announced a rotary-engined hybrid electric car earlier this year.

However, the rotary engine mentioned on the side of the big car seen here is of a very different kind. Walter Macomber and his Macomber Rotary Engine Company in Los Angeles created an axial engine as early as in 1909. This was an air-cooled engine with seven cylinders, built on an axial scheme with a single rotating cylinder block. Yes, the block with all its seven cylinders was rotating. According to its creator the main advantage was that it would improve the cooling of the cylinders due to constant blowing without the use of additional fans. Early versions produced up to 60hp at 800 to 1,400 rpm and it's one of those powerhouses which is believed to have been mounted in the vehicle, seen in San Diego in 1915.

According to one source, “The Macomber Rotary was used in numerous prototype cars between 1914-1918... A factory in Sandusky, Ohio, was primed to mass-produce Eagle-Macomber motor cars. Macomber even drove an Eagle-Macomber car from Los Angeles to Chicago in November-December 1916 to prove the engine’s worthiness.”

Some of Macomber’s rotary engines found their way to aeroplanes, too, but it seems that the inventor had trouble selling his patented design. A 1915 advertisement promised: “Will replace all other gas engines,” but with the in-line engine having become the norm by that time it never happened. A smaller version of the rotary engine from 1916 came with five rather than seven cylinders but once again it never achieved its hoped-for success, and by 1918 the designer had given up.

We wonder if any cars with this fascinating engine design could survive today?

Words: Jeroen Booij; picture: Cynthia Anderson (Cynthia's Hi-Desert Blog)
 

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