page_title: Mamod
section_title: SP4 and SP4D
hierarchical_section_title: Mamod / The SP Range 1979 - to date / SP4 and SP4D
caption_attribution_description: English: A Mamod SP4 engine. Permission granted by http://www.freewebs.com/lesmarsh to upload this image.
context_page_description: Mamod is a British toy manufacturer specialising in manufacturing live steam models. The company was founded in 1937 in Birmingham in the UK by Geoffrey Malins. The name is a portmanteau of Malins Models. Malins started off making steam engines which were sold under the Hobbies brand name but he soon started selling them under the Mamod brand name. The first models produced were of stationary steam engines. Much later the company also began creating models of road rollers, traction engines, steam wagons and other steam road vehicles. These models were aimed at the toy market, so were simple to operate and ran at low boiler pressures for safety but were not accurate scale models.
  Most Mamod models use simple but effective oscillating cylinders, usually single-acting. Some of these engines have regulators either in the steam feed or exhaust but many others run unregulated or have a simple reversing mechanism to alter the cutoff, thus controlling the power/speed and direction of the engine.
context_section_description: The SP4 was the mid-range engine in the SP series. It featured the standard Mamod drawn boiler and die cast chimney. The engine frame for this model was mounted on a silver plinth, and the unit had a reverser which allowed the engine to run in either a reverse or forward direction. It could drive a good selection of tools simultaneously, using a lineshaft, and it also featured "exhaust to chimney".  The boiler was heated using the two-tablet burner tray as on the SP2 and 3, and a whistle was also included on it. The SP4D variant had a uni-directional engine unit and carried a larger pulley to drive a dynamo connected to a small 3v lamp.
  Minor variations in the type:
  Some sight glasses were secured by screw as opposed to 2 pop rivets
  Some sight covers could be a silver metal or brass
  The SP4D version sported a dynamo and an additional extra large pulley (on the same shaft) using a standard flywheel. It had no reverse control lever.
caption: A Mamod SP4 stationary engine
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