LeeRoy Yarbrough, Ray Fox, and the Hemi Swamp Monster

REVISED AND EXPANDED — Part NASCAR stocker, part NHRA funny car, this Dodge Coronet driven by LeeRoy Yarbrough used a supercharged 426 hemi to set the world’s closed-course speed record in 1965. 



Smokey Yunick didn’t run the only damn garage in Daytona Beach. A half-mile south of Smokey’s place, on the opposite side of the foot of the Seabreeze Bridge, Ray Fox (1916-2014) ran his shop, Ray Fox Automotive. Both facilities were hard up against the swampy Halifax River, encouraging the occasional alligator to wander in.

Like Yunick, Fox was a shrewd race car builder as well as a commercial garage operator. In 200 NASCAR Grand National starts as a team owner and crew chief, he scored 14 wins and 62 top fives, with drivers including Junior Johnson, Buddy Baker, and LeeRoy Yarbrough, a young modified standout he signed in 1964.


For 1965, Fox and Yarbrough, then 28, were parked on the sidelines thanks to Chrysler’s boycott of the Grand National season, precipitated when NASCAR boss Bill France banned the 426 hemi engine the previous October. All dressed up with a brand new ’65 Coronet and nowhere to go, Fox decided to modify the car to take a stab at the world’s closed-course speed record at Daytona International Speedway, only a few miles up the road from his shop.

At the time, the mark was 181.561 mph, set in 1961 by Art Malone in Bob Osiecki’s Mad Dog IV. An old Kurtis-Kraft Indy roadster in which Osiecki had crammed a supercharged 413 Chrysler, Mad Dog sported an implausible-looking pair of upside-down wings and a giant aluminum tailfin to keep the beast going straight and pinned to the track.

Fox figured he wouldn’t need to go to such outlandish lengths. The previous year’s pole speed at the Daytona 500 was nearly 175 mph, and Fox had seen Yarbrough top 176 mph with their ’64 Dodge hemi in practice laps. With a few select upgrades, a NASCAR Grand National car ought to be able to best Mad Dog’s speed, Fox decided.


Shown above is the main upgrade. Fox assembled the monster 426 Hemi V8, with West Palm Beach drag racer Ollie Olsen providing assistance on the GMC 6-71 blower and Hilborn fuel injection setup. For sustained high speeds on the big, high-banked oval, Fox constructed two auxiliary circuits driven by electric pumps, one for the fuel injection and the other for the cooling system. The Jimmy blower was set up to run at a 1:1 drive ratio, but a second pulley set providing 18 percent overdrive was ready if needed. Fox told Benny Kahn, famed sports writer for the Daytona Beach News-Journal, “I believe this car will develop 1,000 horsepower.”


A foot-tall doghouse on the hood (above) was required to clear the big blower and Hilborn bugcatcher. For reduced drag and safer handling, Fox dropped the nose of the Dodge down over the big Firestone tires as low as it would go. Tail straight out and belly to the ground, Southerners might say.

All that remained was for driver Yarbrough to take the monster out on the track and give its tail a pull. And that he did on February 26, 1965, two weeks after the Daytona 500. On a dirty, sandy track with a mean crosswind, Yarbrough stood on the gas and ran 181.818 mph, just nicking Malone’s record. For their efforts, Fox and Yarbrough collected a big plywood check for $10,000 from Big Bill France—and a lasting place in racing lore.



As the story goes, Yarbrough set the record speed of 181+ mph on lap two of the run, and was stepping up his speed on the third lap when the Dodge reportedly began to show smoke. NASCAR officials then threw out the black flag, sending Yarbrough to the pits. There, his crew discovered a quarter-inch machine screw lodged in the right-front tire. When it’s your day, it’s your day.


 LeeRoy Yarbrough at speed in the supercharged hemi monster. 

Left to right: builder Ray Fox, driver LeeRoy Yarbrough, sponsor George Hurst 

LeeRoy Yarbrough with Miss Hurst, Pat Flannery Stephens