By Steve Wright, 12/20/2012
Evolution of the Hot Saw
Cahoon has played major role in developing juiced up cookie cutters
If you believe in fate, Dennis Cahoon's 62 years on this earth might serve as an example. He raced motorcycles as a young man, before embarking on a 32-year career as a logger and timber-faller in California's Sierra Mountains.
It's as if Cahoon were destined to make hot saws – the high-powered chainsaws featured in STIHL® TIMBERSPORTS® most exhilarating and, oftentimes, exasperating event. It's hot-rodding for lumberjacks, complete with the thrill of victory and the agony of defeat, compressed into less than 10 seconds.
"People just started hot-rodding the chainsaws," said Cahoon, who lives in Chico, Calif. "Real good (timber) fallers had mechanics working on theirs to make them go real fast. As far as the engines involved, it jumped from chainsaws to go-kart motors. Then the motorcycle came around, then the snowmobile (engine) got involved, with Russ Lemke."
"I always wanted to build a hot saw out of a motorcycle engine," added Cahoon. "That's how it evolved for me."
And as long as Cahoon is around, the evolution of the hot saw will continue. In the last few years, Cahoon has had the opportunity to experiment with replacing the heavier aluminum parts of a hot saw with lighter carbon fiber, thanks to a meeting with a Formula 3 race car manufacturer. The result is T.J. Bexten's hot saw, which weighs 10 to 15 pounds less than the typical ones employed by most STIHL TIMBERSPORTS Series pros, which weigh about 60 to 65 pounds.
"(Bexten's) is right at 50 pounds, a hair under," Cahoon said.
Economically, carbon fiber parts are out of reach for most competitors. Hot saws are a big investment to begin with.
Ten-time STIHL TIMBERSPORTS Series champion Jason Wynyard of New Zealand probably has $15,000 invested in his hot saw, according to Cahoon. But a more typical investment is $5,000 to $6,000, still a tidy sum.
"Carbon fiber costs a lot more money," Cahoon said.
DC Hot Saws is the name Cahoon has given to his home shop, which he describes as a hobby rather than a business. It's not like there's a huge demand for competition-level hot saws.
"There's just a small group of people doing it," he said. "It's around the world, but a small group."
Cahoon's primary goal isn't to make a hot saw that will necessarily challenge the STIHL TIMBERSPORTS world record for three cuts in 19-inch wood of 5.085 seconds set by Matt Bush in 2003. It's to build hot saw that will allow someone to stay competitive and take a bit of the make-or-break aspect out of the event.
Cahoon relies primarily on the 250 cc Honda CR motor to do that.
Arden Cogar Jr. doesn't run one of Cahoon's hot saws, but he's quite familiar with his work.
"Dennis is a very skilled fabricator and has had his hands on the development of at least 20 to 25 (hot saws) used on the 2012 Series," Cogar said. "His ideas are sound. His knowledge of the two-cycle engine is vast. He is a motor-head personified – building race engines that are pound-for-pound the most powerful motors in racing sports."
Cahoon competed in the STIHL TIMBERSPORTS Series for three years in the mid 90s, and he continues to compete in various lumberjack competitions around the U.S. But he's had both hips replaced after three decades in the logging business, and he seems content with his hot saw hobby.
"I'm trying to make a user-friendly saw, something that will get you in the seven-second range," Cahoon said. "It's a task to make three cuts. It's something that's got to be learned."
In other words, no matter how good the machine is, the sawyer still has to have some skill.
"There's a time to race and a time to just make your cuts," he said. "I'm trying to get people into an affordable, user-friendly hot saw.
"It's all about how it handles. That's what I don't like about the Rotax (snowmobile engine) hot saws. They steer you, instead of you steering them. If it's steering you, and you can't make three cuts, you're not going to be any good."
Cahoon has made hot saws from motorcycle engines as big as 500 cc's, but those are primarily for the 27- to 30-inch wood that is used in some western U.S. lumberjack events.
"The optimum is 250 to 350 (cc's) for 20-inch wood," Cahoon said.
While the hot saw engines have changed over the years, the chain itself has seen remained essentially the same.
"You've got a chain speed of about 200 miles-per-hour," Cahoon said. "It's kind of funny, because the chain hasn't evolved too far from where it was back in the 50s and 60s. It's a limiting factor.
"A lot of people don't think about the chain. A sharpened chain makes a really big difference. If you have an average motor and a good, sharp chain, you'll probably win more contests than having the best motor and an average chain."
If anyone would know that, it's "motor-head personified," Dennis Cahoon.