Starting in 1966, one of the last races of the season was the “Roundup” in West Yellowstone, Mont. This organized speed run used North American Championship Drag rules, and snowmobile companies brought whatever their engineers could think up to make their brand the fastest.
In those days, it was hard to find an engine with good power that would work in a snowmobile. Multiple-cylinder engines were built by hand.
In 1968, Cat used twin Hirth 600cc engines with megaphone exhausts. Polaris and others used a West German-made JLO 744cc modified motor.
In the fall of 1968, Bill Ness from Arctic Cat Racing had his friend, Dick Schellbach of Rush City, Minn., make a three-cylinder engine. Ness sent Schellbach 11 new-in-the-box 372cc JLO single-cylinder engines to work with, boring them out to 396cc for more power. Schellbach made a wood model of his crank case to make a sand-cast one for his new 1188cc three-cylinder engine. Using single-cylinder cranks, he put together a three-cylinder crank and mounted the engine in a 1969 Arctic Cat Panther with a jackshaft and megaphones. He brought it to Cat in mid-season to test how competitive it was in real racing.
That same year, Wayne Burkel spent the season racing for Polaris. Wayne borrowed his dad’s TX 500 with a 744cc JLO engine for a jump at Roseau, Minn. He flew 84.9 feet with that heavy sled! In 1969, Wayne switched to Arctic Cat, racing a 744cc Cat until this new sled from Ness came along. Wayne was a smaller guy at 145 lbs., but at 23 years old, he sure liked the power and speed of the monster three-cylinder Cat. Schellbach said this engine produced 90hp using handmade crimped megaphones.
The new sled from Ness had a lot of power, but with few traction products available, it was a handful to steer. Wayne said it was still really fun!
At season’s end, everybody went to the West Yellowstone Roundup for the racing and speed runs. Two weeks before, AC tried to mount a second engine on Wayne’s sled, asking Schellbach to come up with another engine. The factory made up a longer jackshaft for the two driven clutches to sit side by side.
Cat sent a plane to pick up the other engine. After mounting it, they were off to Yellowstone. The front engine had three throttle cables, but the rear engine had only one cable with the HD carburetors turned on their sides. There was a right throttle lever for the front engine; the left side of handlebar sported a rear engine throttle and a brake lever. Other sled makers with twin engines had the rear engine running backwards, with clutches on the right side and cylinders turned around.
With twin 1188cc engines, the sled had a displacement of 2376cc! Clutching was provided by Salsbury 1190s, both on the left side of the Panther. Wayne’s custom hood simply read, “Do Your Thing!”
At the speed run, Ski-Doo’s double-engine Eagle hit 95.30 mph. Wayne’s first run was 95.03 mph, just 0.27 mph slower. While getting ready for the second run, the team noticed the rear idler wheel had lost rubber, so they just trimmed off the other wheel’s rubber to make it even.
Unfortunately, when the Arctic Cat crew started the rear engine with starting fluid, the crank failed. With more time, they would have made plastic wheels and a carburetor shield so Wayne could have leaned forward out of the wind and not have his suit sucked into the intake to make up that little bit of speed.
Sadly, this sled was in a display building that caught fire on May 6, 1973, and was completely destroyed. To this day, Wayne still wishes he could have made another run.
Schellbach and his son, Rick, made two more Cats with these types of engines. In 1971, they had a Panther that was longer and wider that used tuned pipes, and they called it Watashi The Cat. Unluckily, that one was also destroyed in a fire. They also built a Puma with direct chain drive and no clutches, and that one might still be around out west somewhere.
Minnesotan Les Pinz is a vintage sled expert with an extensive collection of historic and other antique sleds, and is a former snowmobile racer. He is a member of the International Snowmobile Hall of Fame and one of AmSnow’s regular test riders.