Blackburn Cirrus Minor

The Blackburn Cirrus Minor was the British manufacturer Blackburn Aircraft a piston aircraft engine for general aviation. Derived from the engine was A.D.C. Cirrus, which by the predecessor Cirrus Engines Ltd.. was produced from 1925. This was the four-cylinder OHV engine first introduced in 1933, initially with a bore of 95 mm and a stroke of 127 mm. In the same year the series production began. Blackburn took over 1934 Cirrus Engines Ltd.. and led the series production of the engine on. He was subsequently widely used in several versions. In 1937 the compression was increased, thus increasing the performance accordingly.

A key design feature of the engine were arranged hanging air-cooled cylinder made ​​of high alloy steel that have been rotated out with their fins made ​​of solid material. The individual cylinders were mounted with short anchor bolts on the crankcase. Per cylinder, there was an inlet and an outlet valve. The aluminum cylinder heads were joined by eight bolts to the cylinders. The rocker arms were protected by an electric cover. The Slipper aluminum pistons had two compression rings and one oil scraper ring. The connecting rods were forged Hiduminium. The forged and fully machined crankshaft consisted of a high strength steel alloy. She was supported in bearings made of white metal. The tensile forces of the direct-driven propeller were taken from a radial ball bearing in the front of the crankcase. This was made of electron as the upper housing cover. The camshaft ran directly in the casting of the crankcase and was driven by a spur gear. The lubrication caused a circulation system with a piston pump. For the mixture supply was a downdraft carburetor Claudel - Hobson with mixture adjustment and flame screen. Fuel was supplied by Amal fuel pumps, which were driven by a shaft on the rear cover of the appliance. For the two shielded ignition systems of BTH were provided, the magnets were attached lid also on the back. In addition, electric starter and a filter device could be mounted.

The 1945 introduced Cirrus Minor II had increased to 100 mm bore, the compression was now increased to 6.5:1. This made the use of fuel with 77 octane needed. Also leaded petrol was permitted. In order to improve the lubrication of the rocker arm, the cylinder cover has been changed. The exhaust was fitted with a Stellite filling what their service life increased. When it came to a carburetor version of Zenith with automatic preheat for use.

Cirrus Minor has been installed in a number of models of general aviation Taylorcraft and Miles.

Specifications

Minor Minor Minor I II Bore mm 95 95 100 Stroke mm 127 127 127 Displacement l 3.6 3.6 3.99 Compression 5.1:1 5.8:1 6.5:1 Length mm 960 1013 Width mm 440 455 Height mm 636 650 Weight kg 95,108,113 Starting power PS/min-1 80/2400 90/2600 100/2600 Travel service PS/min-1 70/2200 80/2300 90/2300 literature

• "British Piston Aero Engines and Their Aircraft ," Alec Lumsden, ISBN 1853102946
• Jane's all the world 's aircraft 1945
• Piston aircraft engines, Hans Giger, ISBN 3613010895
• Encyclopedia of aircraft engines, "said Bill Gunston, ISBN 361301422X

• Propeller engine
• Line engine (aviation )