Ask MO Anything: Why Do We Still Use Camshafts?

Arctic Cat’s 2014 design uses reed valves instead of intake valves, and a two-stage fuel injection system that also introduces fuel (and lubricant) into its transfer ports via slots in the rear of the pistons at high rpm. Arctic Cat rates the 600 at 123 hp at 8100-8300 rpm. They also say it weighs 10 pounds less than competing direct-injection engines, so it’s way lighter than anything with cams, drive gear, and valves. You can see the compactness, and AC says it’s also Tier III EPA compliant – which we believe is not quite CARB but close….