Centrepiece of the CB1100 is its handsome DOHC engine. Air (via 2mm fins) and oil-cooled (via a 335mm 9-tier, front-mounted oil cooler), the finning is the finest found on any bike within the Honda range, and new production methods had to be found for its manufacture. It revs to 8,500rpm and features a compression ratio of 9.5:1. Maximum power output is 66Kw, with a peak torque figure of 93Nm @ 5,000rpm.
Importantly, however outright horsepower figures on Dynograph paper was not the goal – if the engine proved fun to use, then it would be deemed a success. Smooth, instantly accessible power and torque is what the CB1100's motor's all about, and plenty of it, anywhere in the rev range. No frantic thrashing to the redline; just dial in the throttle, and go. Four-stroke, four-cylinder motive thrust at its creamy, effortless best.
Extremely efficient PGM-FI fuel injection, utilising one 36mm throttle body, gives excellent fuel consumption of 25.1km/l (70.9mpg) @ WMTC.
Bore and stroke is set at 73.5mm x 67.2mm. Drive for the twin camshafts is via central chain, and the valve included angle is 26.5° inlet and exhaust. Inlet valve diameter is 27mm, with a 2.5mm stem; exhaust 24mm with 2.5mm stem. A single, secondary balancer shaft ensures smooth running and drive is transmitted via wet clutch and five-speed gearbox. Final drive is by 530 chain.