Mamod - Steam machine Steam Engine SP1 - 1950-1959 - U.K. The SP1 was based on the Mamod Minor 1 which it replaced and which had been in production since 1939. It had the same boiler, similar engine unit and flywheel to the non-crank disc types. The main differences were that it had a new black die-cast chimney and a narrow solid fuel burner design to take one tablet broken in half. This was also the only SP engine to feature a water plug as the boiler was too small to fit the standard Mamod water sight glass. The firebox remained the same as the older Minor 1. Some were built with the old Mamod Minor 1 boiler. The exhaust was a simple open port as on the Minor 2 and MEC1 engines. These engines with limited power and torque could drive at least 1 or 2 miniature tools. The SP1 was discontinued in 1985 after 27,500 had been produced. Engine is 5.5" x 3" x 6" ( without wood base ). Not tested for working condition, missing the burner. Denver, Colorado toy collector estate.~~ DEAR BIDDERS, Please View More Detailed Close-Up Images by visiting our website - Sofedesignauctions.com ~ Thank you ! ~~~~~~. Detailed condition reports are not included in this catalog. For additional information, including condition reports, please contact us at info@sofedesignauctions.com