Blackburn Cirrus Major
The Blackburn Cirrus Major was a piston aircraft engine made by the British manufacturer Blackburn Aircraft for general aviation. The engine was derived from the Cirrus Hermes IV , which was produced by the predecessor company Cirrus Engines Ltd. was produced from 1929.
history
The four-cylinder OHV engine was presented for the first time in 1936 . It was then widely used. Series production began in the same year.
technology
The hanging air-cooled cylinders made of high-alloy steel, turned from solid material, were an essential design feature. The cylinders were fastened to the crankcase at their centered base flange with four bolts each. There was an intake valve and an exhaust valve armored with stellite per cylinder . The cylinder heads were made of aluminum and were connected to the cylinders by twelve bolts. The aluminum slipper pistons had two compression rings and an oil control ring. The connecting rods were made of forged hiduminium (an aluminum alloy). The forged crankshaft, machined on all sides, consisted of a high-strength steel alloy. It was mounted in plain bearings made of white metal with steel shells. The thrust of the directly driven propeller was absorbed by a radial ball bearing in the front part of the crankcase. This was made of an aluminum alloy, the upper lid of which was made of electron. The camshaft ran directly in the cast part of the crankcase and was driven by a spur gear. A downdraft carburetor from Claudel-Hobson , which had an automatic mixture preheating, was used to supply the mixture. The lubrication was carried out by a dry sump circulation system, for which a piston pump with suction and pressure stage provided. Two systems from BTH were used for the ignition . If required, the ignition system could be delivered completely shielded. The fuel supply was ensured by an Amal duplex fuel pump. An electric starter, vacuum pump, generator and filter device could be mounted on the rear cover of the device.
commitment
The Cirrus Major was only installed in the Blackburn B-2 , a school double-decker with an unusual arrangement of seats next to each other. In 1939 the performance of the Cirrus Major II was added, which was installed in several of their aircraft by General Aviation and Miles . The even more powerful Cirrus Major III was presented in 1945. Around 700 of all versions were built.
Technical specifications
Major I Major II Major III Bohrung mm 120 120 120 Hub mm 140 140 140 Hubraum l 6,3 6,3 6,3 Verdichtung 5,1:1 5,8:1 6,5:1 Länge mm 1250 1072 1080 Breite mm 444,5 465 429 Höhe mm 762 777 754 Gewicht kg 136 147 156 Startleistung PS/min-1 135/2300 150/2450 155/2450 Reiseleistung PS/min-1 125/2100 138/2200 145/2200
Web links
Individual evidence
- Alec Lumsden: British Piston Aero Engines and their Aircraft. The Crowood Press Ltd., Ramsbury 2003, ISBN 1-85310-294-6 .
- Jane’s all the world's aircraft 1945.
- Hans Giger: piston aircraft engines. Motorbuch Verlag, Stuttgart 1996, ISBN 3-613-01089-5 .