Tornado Watch

Stringent EPA and California Air Resources Board (CARB) emissions initiatives put hand-held equipment manufacturers on the hot seat. These companies play a constant game of R&D tweaking, fine-tuning and testing to meet rigid restrictions.

Environmentally driven legislature pushes manufacturers back to the drawing board, where some experiment with engine alternatives that will burn cleaner – just clean enough. “You can’t look at your engine and design it for the next year,” noted Paul Golevicz, marketing service manager, Echo, Lake Zurich, Ill. “You have to look years down the road and make a technical assessment and say, ‘Is this the technology that will get my company down the road?’”

And down the road, the clamps tighten. The Clean Air Act’s multi-phase timetable for compliance will require hand-held equipment to operate at only 37 grams/hp per hour, compared to 184 grams/hp per hour in 2001. “You can see that the EPA and CARB have not cut this industry a break,” Golevicz related. “Every year, the manufacturers have to meet more rigid standards until we meet the goal the EPA has predetermined for us.”

This means more experimenting. And more changing. “We have to remain limber and flexible,” Golevicz explained, noting that some companies have turned to alternative technologies like four-stroke engines, hybrid two-four stroke engines or stratified-charged models.

Four-stroke engines use a separate valve train to control fresh fuel mixture inflow and outgoing exhaust gasses, allowing control over inflow and outflow. The hybrid two/four-cycle version uses the same oil-fuel mixture as its two-stroke cousin, but a valve train allows for more inflow/outflow control. This version creates more moving parts, but the lubrication method mimics two-stroke engines. Stratified-charge models are a third option and involve complex carburetion and fuel delivery systems.

Echo opted to stick with the two-stroke.

After investing a couple years in redesign, it introduced Power Boost Tornado engine at the Green Industry Expo. The modified two-stroke engine ultimately will reduce engine emissions 85 percent from historic levels while improving engine efficiency 35 percent, the company reported at its press conference. More than 80 Echo products will feature the technology, and those who purchased older models can retrofit their equipment with Power Boost Tornado, Golevicz said.

The crux of the technology lies in the engine’s guts. “Our engineers have paid specific attention to the operation and design of how the combustion chamber operates, and part of that includes directing and controlling the fuel and air mixture into the cylinder,” Golevicz described.

Short circuiting, or losing unburnt fuel through the exhaust, is a leading problem with hand-held, two-cycle engines, Golevicz pointed out. Power Boost Tornado virtually eliminates this with two key, intrinsic actions. First, the fuel-air mixture is pressurized and spins through tight ports so it enters the combustion chamber in a thoroughly mixed “tornado” motion. Next, chamber design and piston movement cuts off fuel-air mixture short circuiting, so less of the mixture has a chance to make it to the exhaust port.

“We are controlling the inflow, pressurizing it and turning it into a high-powered swirl of fuel and air into the combustion chamber,” he said. “The [swirl] intermixes with the remaining exhaust from the previous power cycle and then the piston closes off the exhaust port before any of the fresh fuel-air mixture can get out of the exhaust port.”

The benefits of this two-cycle technology include a high power-to-weight ratio, which is especially valuable for landscape contractors who spend long hours running the equipment. “When the operators are out in the field running equipment for hours at a time, weight is a big issue and they want to get maximum power for maximum productivity,” Golevicz said. The three moving parts in this two-cycle engine allow the equipment to weigh less, and also reduce the likelihood of failure. These advantages inspired Echo engineers to reconstruct the two-cycle engine, which will meet emissions expectations up to and through 2005.

“Our engineers have been very proactive in looking at this engine for a couple of years to make sure it will work and get us to where we need to be,” Golevicz concluded.

The author is a Contributing Editor to Lawn & Landscape magazine and can be reached at khampshire@lawnandlandscape.com.