Honda RC162
As with the 2RC143, the spine frame is gone, and the new frame is also of the open, double loop type. The frame tubes do not have the same diameter everywhere; where they join the steering head, they taper out to a larger diameter for increased strength and rigidity.
The engine is further developed and although compression ratio (10.5 : 1), valve angles (36 degrees inlet, 40 degrees exhaust) and bore and stroke (44 x 41 mm) are still the same, it now delivers, according to Honda, over 40 bhp at 14,000 rpm. Most sources at the time claim 45 bhp. In view of the difference in speed with its predecessor, the RC161, the latter figure must be true. The cylinders are inclined 30 degrees, and the engine is 80 mm narrower, and to improve aerodynamics no longer has the wet sump – the oil is now carried in a tank under the seat.
This latter move is in the first instance not a great success, the bikes suffer from overheating. Some interesting data: diameter of the inlet valve head is 19.5 mm, exhaust valve head is 17.5 mm, shaft diameter of both valves is 4.5 mm. Lift of the valves is 5.8 mm for the inlet and 4.5 mm for the exhaust valves.