Can-Am News
CAN-AM NEWS
Biggest news at the Can-Am factory in Valcourt. Quebec when a group of motorcycle journalists visited the facility last winter was the development of a 500cc four-stroke Single.
A working prototype has been built at Valcourt, but it was in Florida when the editors were in Quebec. Blueprints of the engine, designed by Rotax of Austria to Can-Am specifications, were casually lying on a table in the styling department when the editors toured Can-Am’s R&D department. The engine will be an oversquare, sohc, four-valve with the cam driven by a „toothed belt instead of a more conventional chain. The single cam will operate four valves via rocker arms. Two exhaust ports and two exhaust pipes will be used. The first prototype has produced 38 bhp at the countershaft, but the engine is expected to produce around 40 bhp when it is introduced in the fall of 1980. Maximum power, if the engine is developed, is estimated to be around 45.
Like the Honda 500cc four-stroke, the Can-Am engine will have a counterbalancer. but the Can-Am balancer will be driven by a gear, rather than a chain. Because the counterbalancer fits quite closely to the crankshaft, there is very little additional size needed in the crankcase for the balancer.
The first prototype used a crankcase machined out of solid aluminum, resulting in a heavy and not-production-looking engine. It w;as also heavy. Still, the prototype 500cc enduro bike weighed in at just over 280 lb. dry, according to Can-Am. The final motorcycle should w'eigh 250 lb. drv. or about 20 lb. less than Honda’s XR500.
Around the engine will be a conventional single dow ntube, cradle-type frame. Suspension components should be similar to other Can-Ams, meaning Marzocchi front forks, but the shocks won’t necessarily be Girlings. Can-Am will most likely use Ohlins on the rear of next year's new motocrosser, the MX-6, and could use the Ohlins on the four-stroke enduro. Even the Marzocchis are new. Prototype MX-6 motocrossers had new air/spring Marzocchis xwith 11.8 in. of travel. All-new internals are said to have less compression damping than current models.
Current plans call for introducing a street version of the four-stroke in 1981. Another street bike, described as being a Multi, no more than 370 lb., between 700 and 900cc. having a low' center of gravity, and lots of power is being designed now. It will be another year before the engine configuration is known and final plans for the big bike are made.
Details of next year's MX and Qualifier enduros have been worked out, however. Most exciting of the models will be the MX-6 500. Not a real 500cc, it will be a 400cc version of the present 370, but it is said to produce 50 bhp. So as not to humble the suspension, the new Marzocchis in front will be mated to Ohlins in the rear, both with nearly 12 in. travel.
Can-Am will abandon the oil injection on all models next year, but the large diameter backbone frame will remain— with a difference. Two small scoops, one on either side of the steering head, are welded on, funneling air from behind the front number plate through the frame and into an airbox sealed by the seat. By drawing air in from the front of the frame there is more room between the seat and the rear tire so the increased travel rear suspension doesn't need any higher seat height. CanAm R&D people claim the new' intake system improves power. The frame is otherwise changed by a new rear hub which moves the brake rod from the left to the righthand side of the motorcycle, getting rid of the brake lever crossover and saving 3 lb.
With the 370cc being expanded to a 404cc which is being sold as a 500. the 250 w ill remain and be expanded to 288 which will be sold as a 350. The 175 will remain the smallest Can-Am.
