The Mechanair 5.9 cc spark ignition engine was a basically conventional sideport spark ignition unit which was manufactured to very high standards in Birmingham, Warwickshire (now part of the West Midlands conurbation) between the first half of 1946 and early to mid 1948. The manufacturers of the engine were a firm called Mechanair Ltd. of Birmingham.
There has been a great deal of past confusion over the engine's name, arising from the fact that for the first 7 or 8 months of its production life it was marketed by the Astral Aero Model Company (Astral) of Dixon Lane Road in Leeds, Yorkshire, who applied their own company name to the engine. However, beginning in early 1947 the manufacturers took over the marketing of the engine from Astral, thereafter designating the engine as the Mechanair P1 5.9 cc model. Latter-day research has confirmed that the the engine remained the same throughout this period apart from a few very minor modifications - only the name changed.
At some point later in 1947, a further variant of the Mechanair appeared, presumably designated the Mechanair P2 model, although we have no hard evidence for this. The revised unit sported a red cylinder head but was otherwise essentially unchanged from its predecessor. Production ceased at some indeterminate point in 1948, after perhaps around 700 examples had been manufactured in total. The engine was revived during the 1980's through the appearance of a limited number of fine near-replicas produced by Dunham Engineering.
A full review and test of the Mechanair 5.9 cc design will appear in due course on this website.