The SE4 is an early example of Mamod twin cylinder stationary engine. The model was introduced in 1936 but changes were made the following year and this example is the 1937 version, with whistle and lubricator. The SE4 was a twin cylinder version of the SE3 which, at that time, was single cylinder. These pre-war versions of SE3 and SE4 were soon discontinued and not many were made compared with the SE1 & 2. Mamod didn't make another twin cylinder engine until the 1970's, confusingly named SE3.
The impressive 4 wick meths burner sits under a low slung boiler; 6" long x 2" diameter. The boiler is fitted with a small overflow plug, 1/4" safety valve, a Bowman style whistle, steam dome and chimney.
Steam is fed from the dome via an in-line lubricator and a T joint to the two port faces cast into the cast brass engine frames. The crank shaft has disc cranks at each end and, between the frames, a flywheel with integral pulley and a small gear wheel. The gear wheel meshes with a larger one on a counter shaft mounted above the crankshaft, giving a 3:1 speed reduction. The counter shaft is fitted with a small pulley at each end.
The cylinders are of a pseudo-flanged design, 5/16" bore and 3/4" stroke. The pistons have oil grooves turned into them. Exhaust steam is taken through two pipes to the chimney. All pipe joints apart from the T are screw compression fittings.
Condition is generally good for the age of the engine. There are signs of resoldering repairs but all parts appear to be original. The paintwork also appears to be original. However, the underside of the base is a darker red than the upper, so this might not be so. There is some surface rust on the base but, considering the rarity of this engine, I will not repaint. Interestingly, there are two decals, the traditional transfer and also a second one, which is stamped or engraved into the base. The burner might not be original because it looks in better condition than the rest.
The purchase price is not stated below because the engine was a prize in the 2010 STWWW organised by the Unofficial Mamod and Other Steam Forum.