Cirrus Minor (engine)

The Cirrus Minor was a British four-cylinder in-line air-cooled aero-engine designed and built by the Cirrus Engine Section of Blackburn Aircraft Limited.

Design and development

The Cirrus Minor started life as a development of the original Cirrus series of engines which progressed through a number of variants Cirrus I, II, & III. Each with slightly different displacement and power. Later Cirrus was bought by Hermes Engine Company and they produced the Cirrus Hermes I, II, III and IV. Again each differing slightly in displacement and power.

In 1934 Cirrus was bought again by the Blackburn Aircraft company and later that year the Cirrus Minor was produced and in 1935 the Cirrus Major was produced.

The Minor was known for excellent reliability, and had a major "win" when it was selected to power the RAF's Taylorcraft Auster observation aircraft. The RAF's version had several modifications, known as the Series I. Although externally identical, the Series II engine was redesigned to operate on 77 octane fuel, as opposed to the original's 70, increasing power to 100 hp (75 kW).

Application

* Auster J-1 Autocrat
* Auster J-4
* British Aircraft Swallow
* Miles M.18
* Miles Gemini
* SAI KZ III
* Taylorcraft Auster I
* Taylorcraft Plus C2
* Taylorcraft Plus D
* VEF I-12

pecifications (Cirrus Minor I)

pistonspecs

type=inline air cooled inverted 4 cylinder
bore=95 mm (3.74 in)
stroke=127 mm (5.00 in)
displacement=3.6 L (230 cu in)
length=958 mm (37¾ in)
diameter=

width=419 mm (16.5 in)
height=635 mm (25 in)
weight=88 kg (195 lb)
valvetrain=1 inlet and 1 exhaust valve per cylinder
supercharger=
turbocharger=
fuelsystem=1 Claudel carburetor
fueltype=70 octane
oilsystem=
coolingsystem=air
power=95 hp (71 kW) @ 2600 rpm
specpower=
compression=5.80:1
fuelcon=
specfuelcon=
oilcon=
power/weight=3.1 lb/hp @ cruise speed

References

*http://www.oldengine.org/members/diesel/Duxford/data01.htm
*