Hier das Team um Chef William Lear (Lear Motors Corporation), 2.v.l. mit einem Prototypen der Maschine.
Das schreibt Rick Popely/L. Spencer Riggs dazu (nur in englisch):
''Few people took William Lear's entry seriously. But Following two years of near misses by the exotic turbine-powered cars, others felt anything could happen. What Lear, of aircraft fame, proposed was using space-age technology to harness one of man's oldest sources of power. Lear's "Vapordyne" Indy car was to be powered by steam. It sounded farfetched, until one realized the simplicity of the idea.
The racer was to carry a small tank of keroseneor propane to operate the boiler, with pitstops made to replenish water as the primary fuel source. Lear's Delta Motor design was a 6-cylinder with 12 driving pistons operating three crankshafts in a triangular arrangement. The four-wheel drive chassis was super light, and the horsepower output was said to be higher than the conventional Ford or Offy. Calculations had the car going the distance on two pit stops.
However, even though the sleek racer did the rounds of the auto shows, time ran out on the project before May '69. And after the fallout from the new rules governing the turbines USAC never did arrive at a definite way to measure the Lear Delta's horsepower.
Eventually Bill Lear dropped the project. But the concept behind the Vapordyne still gives pause to those who understand the power of steam."