R.C. Engineering and Action Fours Improve Japanese Motorcycles

West Coast tuners, such as R.C. Engineering and Action Fours, revamp Japanese motorcycles with car parts and more engines.


| August 2012



Motorcycle Drag Racing A History

“Motorcycle Drag Racing: A History” explores a 60-year history through the mechanical aspects of motorcycle drag racing and the people that make the sport so fascinating.

Cover Courtesy Gearhead Publishing

What’s so great about motorcycle drag racing? It’s like a line in the Lovin’ Spoonful song that says, “It’s like trying to tell a stranger about rock ‘n roll.” To those who are dedicated followers of it, the sport makes perfect sense. To those who aren’t, it makes no sense at all. Motorcycle Drag Racing: A History (Gearhead Publishing, 2011) by John S. Stein is for both kinds of people. This book documents the incredible 60-year history of organized motorcycle drag racing with full-color photographs and fascinating stories of the people behind the ever-evolving machinery. Find out how the addition of car parts and engines turned Japanese motorcycles into exceptionally fast and fluid bikes in this excerpt from Chapter 9, “Made in Japan.” 

In 1964, Honda launched an advertising campaign to convince everyone that the nicest people could be found on Hondas. When their CB750 appeared five years later, everyone would also realize that you’d find the quickest people on them. With a 68 horsepower, SOHC, four-cylinder engine, its extraordinary performance was made even more so courtesy a handful of west coast tuners—most notably R.C. Engineering and Action Fours.

Action Fours’ “2x4”

Santa Ana, California-based Action Fours—headed by Bill Hahn Sr., Fred Stepp and Jim Dickinson—was one of the first to sell performance parts for the Honda 750, many of which found their way onto their twin-engine gasser called, logically enough, “2 x 4”.

The machine featured engines bored to 785cc, 12:5:1 pistons, and Kenny Harmon “F” grind cams along with stock carburetors, clutch and transmission. Rather than coupling the engines with a chain between the ends of the crankshafts as everyone else had done, or using a rubber belt as others would soon do, the machine ran a chain from the crank centerline of the front engine to the rear one.

The motorcycle proved formidable even though it weighed 480 pounds, or 175 pounds more than Boris Murray’s twin Triumph, and about 220 pounds more than the quickest Sportsters. At the Hot Bike Magazine/NHRA Nationals in 1972, rider Hahn made a 9.57 .second run at 148.53 mph—four-tenths and eight mph faster than the existing record. He then faced Sportster-mounted John Heidt in the Final—a 9.5 second motorcycle against a 10.3 second motorcycle, a 148 mph machine against a 132 mph one. Although Hahn lost the race (asleep at the starting line), the point had been made.

The event was interesting for other winners as well, two in particular. Russ Collins won B/AB and someone by the name of Terry Vance won C/AB. Things would get very interesting very soon.





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