1000 c.c. MODEL 4G 600 c.c. MODEL 4F
ENGINE - Bore and stroke: 4G, 65x75 mm. {997 c.c.). 4F, 50.4x75 mm. {597 c.c.). Four Cylinders cast en bloc in square formation. Detachable cylinder head with integral radial induction manifold and detachable exhaust manifolds. Totally enclosed overhead valves operated by short push rods. Camshafts and Magdyno driven by automatically tensioned roller chain. The twin crank- shafts are mounted on substantial bearings and coupled by hardened and ground gears immersed in oil in a separate compartment adjacent to the crankcase. Both crankshafts are substantial nickel-steel drop forgings, carrying central flywheels, bobweighted and accurately balanced. Light rigid con-rods with split lined big ends.
LUBRICATION - Dry sump system in conjunction with a separate oil tank holding f gallon. Double plunger pump, one of which forces lubrication through all engine bearings at a nominal pressure of 60 lbs. per square inch. The valve gear is lubricated by pressure, requiring no attention. The scavenging pump returns oil which drains to the bottom of the crankcase by gravity through a star shaped filter back to the oil tank. The oil tank is provided with a large gauze on the delivery side and a separate large capacity vent.
CARBURETTER - Fully automatic. IGNITION - Magdyno with self contained gear driven distributor. 14 mm. sparking plugs. Cut-out switch in instrument panel.
GEARBOX - Four-speed. Foot control.
TRANSMISSION - Engine shaft 3-cam shock absorber. Polished aluminium oilbath chain case, and Ariel outside clutch of large dimensions. Rear chain fully protected and automatically lubricated.
EXHAUST SYSTEM - Two-port. Large and efficient silencers.
WHEELS - Dunlop Tyres - 4G, 26X 4 rear, 26x 3.25, front. 4F, 26x 3.25 rear and front. Chromium rims. Red centres (Black or Ariel Green centres optional). Chromium brake plates. Detachable rear wheel.
MUDGUARDS - Robust ribbed section steel guards, fully valanced. Tail of rear guard hinged to facilitate wheel removal.
PROP STAND - Fitted to offside of machine in addition to two normal stands.
TANK - All steel saddle type with instrument panel. 37/8 gallon capacity. Superbly finished in Chromium and Red, lined Gold. (Chromium and Black or Ariel Green optional .
