Introduced in March 1949 the WD8 was basically the same as the WD1 & 2 engines with slight modifications to the crankshaft and bearings to allow a higher power output. The engine was now capable of 1.5 HP - 3 HP denoted by either Low, Medium or High engine speed simply by changing the strength of the governor springs The WD8 engines also had the option of petrol/paraffin models with the use of a special vaporiser arrangement using hot exhaust gases to vaporise the praffin fuel. A twin compartment fuel tank was used in the case of petrol/paraffin engines. Tank cooling was a further option and details of tank cooled engines can be found in the separate section on tank cooled WD's. Ignition was still by the Wico A series magneto, although alternatives were sometimes used depening on availability. The WD8 range finally came to an end in 1961 with around 36,500 engines being produced.