Honda 250 Four Cylinder

Honda RC160 250 Four 1960

1960 HONDA 250 FOUR. Many people were surprised when Hondas appeared in the 1959 T.T. with beautifully prepared 125 c.c. twin-cylinder models; more were surprised when Motor Cycling scooped the European Press in September of that year by publishing first details of a 250 c.c. four-cylinder Honda.

This 1959 machine closely followed the layout of the 125 c.c. twin, with leading-link forks and spindly looking frame. But the cylinders of the unit were mounted vertically.
The power unit was virtually a double-up of the "125", with shaft and bevel drive to the gear train of the twin overhead camshafts, but on the four this shaft was on the off-side whereas on the twins it was on the near-side.

Only a few months later the first Honda fours arrived in Europe to race—but they were entirely different! Gone were the fancy forks and in their place the machines wore sturdy telescopies, although these retained the telescopic steering damper fitted between the frame and bottom crown member—rather like some BMW.s.

The engine, too, had been redesigned, with its cylinders inclined forwards and drive to the camshafts by a central gear train rather like the Italian 500 c.c. fours. As on the twins, each "pot" had four valves! Much more downdraught had been given to the four carburetters which were now tucked into a recess cut into the fuel tank.
Other changes included the use of a single-leading-shoe pattern front brake, whereas a rather complicated twin-leading-shoe type was employed in 1959.

An incidental advantage of the change-over to gear-train drive to the camshafts was that the clutch, previously shrouded by the bottom bevel-box, was able to be cooled better, a small scoop being fitted to catch air from the side of the motor.

SPECIFICATION
Engine: inclined four-in-line mounted transversely;
250 c.c. d.o.h.c; drive to camshafts by central
gear train. Ignition: coil and battery.
Transmission: six-speed gearbox in unit with engine, final drive by chain.
Frame: spine-type of tubular construction, swinging-fork rear suspension.
Forks: telescopic with hydraulic damping.

 Honda RC163 250 Four-cylinder 1962

The RC163 has some small changes, the most obvious one being larger cooling fins for the cylinders. Internally the engine is the same. Power output is now 46 bhp at 14,000 rpm.The first appearance of a multi cylinder Honda 250 came at the end of 1959, when the Honda 125 made its debut at the Isle of Man Tourist Trophy. After that race Honda withdrew to its factory for a time.

The prototype of the four-cylinder Honda 250 was a very coarse 35-h.p. vehicle that Japanese drivers tried out on dirt tracks. The cylinders of this motorcycle were perfectly vertical, and the distribution utilized a double overhead camshaft with bevel gear shaft. The look of the vehicle was then improved, resulting in excellent detailing. The engine was redone and the cylinders were inclined 30° forward.

The new distribution was gear-operated. This four-cylinder Honda made its European debut in 1960, ridden by the Australian Tom Phillis and the Rhodesian Jim Redman. In 1961 Honda hired Mike Hailwood, and the championship was almost too easy for him with the four-cylinder 250. The following year Hailwood accepted MV Agusta's offer to ride its 350 and 500 models, perhaps hoping to have a more exciting season. This compelled Honda to fall back on Redman, who won the championship in 1962 and 1963 in the 250 class and chalked up two wins in the 350 class.

Motorcycle: Honda 250-350 Four-cylinder Manufacturer: Honda Motor Co. Ltd.,
Tokyo Type: Racing Year: 1962
Engine: Honda four-cylinder, four-stroke, with two-shaft overhead geared distribution and four valves per cylinder. Displacement 249.3 cc. (44 mm. x 41 mm.—250); 339.4 cc. (49 mm. x 45 mm. —350)
Cooling: Air
Transmission: Six-speed block
Power: 46 h.p. at 14,000 r.p.m. (250); 54
h.p. at 12,500 r.p.m. (350) Maximum speed: Over 135 m.p.h. (250);
over 140 m.p.h. (350) Chassis: Double cradle above, tubular,
suspended engine. Front and rear,
telescopic suspension Brakes: Front, central drum, four shoes;
rear, central drum, double cam