Description NSU engine ca 1905 NSU started to produce its own engines in 1904 and used the inlet-over-exhaust principle for a number of years. The inlet valve operation system is special in that the inlet valve is forced open by a rod actuated by the exhaust valve cam. The carburettor, which is not quite complete, is NSU’s own device with its characteristic tank-top control. The engine type we offer here, with cast-iron crankcase, was first presented for the 1905 model range and was catalogued till 1909. It was available in four sizes, 2HP, 2½ HP, 2¾ HP and 3 HP, equivalent to 70x 75 (289 cc) 75 x 75 (331 cc ) 80 x 75 (376 cc ) and 80 x 80 (402 cc) bore x stroke. This engine measures 80×75 (376cc) and has been overhauled by a specialist.
