The first stern drive? Volvo Penta gets credit for the introduction of its Aquamatic 100 in 1959 but the idea of mating a steerable outdrive to an inboard engine was percolating through the industry at the time. Take, for example, the drive system introduced in 1957 by Muncie Gear Works. I spotted this seafoam-green beauty on the transom of a slick little runabout at the annual meet of the Antique and Classic Boat Society last summer in Racine, Wis. and had to do some research to figure out what I was looking at.
The drive at the show appears to be a Muncie Gear Works Model 500 Flexidrive. Muncie Gear Works of Muncie, Ind., might be best known to performance-oriented readers as the producer of renown transmissions used in high-performance muscle cars in the 1960s and 70s, most notably the Muncie M22 “Rock Crusher” four-speed. The company was founded in 1910 to manufacture clutches and transmissions for the rapidly expanding automobile industry. The agile company survived the Great Depression by producing transmissions for potato diggers, automatic coal stokers, heat pumps, air conditioners and commercial deep freezers. Muncie got into the outboard motor business in 1930 building a 2-hp opposed twin. In 1938 it copied the popular single-cylinder 1.2-hp Evinrude Scout motor and went on to make small motors under many brands such as Muncie, Neptune, Sea Gull, Skipper, Mighty Mite and also the Sea King brand for Montgomery Wards, as well as the Motorgo and Waterwitch brands for Sears Roebuck and Company.
There’s very little information available on the Flexidrive, but this clip from 1959 indicates the drive was introduced in 1957. The advantage of the sterndrive at the time was that it could combine the power of an auto engine with the steerable prop thrust of an outboard, and could also be tilted for shallow-water drive or mooring with the drive out of the water.
An ad for the Flexidrive from a 1960 issue of Boating Magazine shows a unit that looks much like the one spotted at the boat show, without the sweeping, stingray-shaped anti-ventilation plate seen on the 1959 model. The Flexidrive appears in “what’s new” reports in boating and mechanics magazines through the 1960s, with models usually mated to Ford gasoline engines and, in 1968, to a 60-hp Isuzu diesel engine. A 1968 report in Popular Mechanics magazine lists 15 sterndrive brands, including Muncie, Brennan, Chrysler, Eaton, Holman & Moody, OMC, Osco, and Stokes Marine, plus of course MerCruiser and Volvo Penta. Pages from a 1971 Muncie brochure reveal both the 500 series and the new “husky” 700 Series Flexidrive rated for up to 225 hp. By then, of course, MerCruiser was dominating the sterndrive field with a 50 percent market share that crushed smaller drive builders like Muncie.