Pat Miller’s triple-engine Yamaha
Motorcycle drag racing is mysterious, even among motorcyclists. The sport hides in a corner of the two-wheeled world that few riders know much about. Yet it is one of the most inclusive motorsports (or any sport) around – riders of all ethnic backgrounds and genders have been successful at the highest level. Whatever your perspective, the machinery of drag racing is clearly impressive.
Underdog innovation is at the heart of it. The parts required to create, harness, and apply horsepower are so specialized they are often homebuilt or adapted from other applications. To hurtle down a ¼ mile track racers began with single-engine machines, then turned to double-engine machines. By the late Sixties there were even a handful of triple-engine drag racers competing. But shortly thereafter drag racing returned to a single-engine sport, which it remains today. Virtually none of the late-‘60s triple-engine beasts are known to still exist.
One survivor is this B/Gas Yamaha of Pat Miller. Miller first built and had great success with a single-engine Yamaha 350cc two-stroke. He then added a second --also successfully-- and eventually a third. The engines are Yamaha TR2 350cc factory road racing motors, generating roughly 60hp each. The bike also features one of the first slipper clutches used on a motorcycle.
An enormous trail bike sprocket was incorporated to compensate for the limitations of the four-inch Avon slick. And not always effectively: the machine would often smoke the tire for the entire quarter mile. Regardless, its best time was 10.09 seconds at 144 mph.
Look closely at the build details of the bike: each motor’s transmission has been sawed away, the headstock is integrated into the tiny fuel tank, the rear axle carrier mounts to the frame with just four 6mm bolts on each side. This is a bike that rewards study.
Thanks to the NHRA Museum in Los Angeles for the loan of this motorcycle. The bike’s current owner, John Stein, recently authored Motorcycle Drag Racing: A History. Copies of this highly acclaimed book are available for purchase here at the Graeter Art Gallery.