The Praga B2 was a low powered

aero engine An aircraft engine, often referred to as an aero engine, is the power component of an aircraft propulsion system. Most aircraft engines are either piston engines or gas turbines, although a few have been rocket powered and in recent years man ...

suitable for very light aircraft. It dates from the mid-1930s.

Design

The Praga B2 was a dual ignition, air-cooled horizontal twin producing 40

horsepower Horsepower (hp) is a unit of measurement of power, or the rate at which work is done, usually in reference to the output of engines or motors. There are many different standards and types of horsepower. Two common definitions used today are th ...

(30 kW) aimed at lightweight aircraft. It was a higher compression version (6.7:1 from the earlier 5.72:1) of the original and otherwise very similar Praga B, which provided 36 hp (27 kW). Its cylinders were machined from alloy

steel Steel is an alloy made up of iron with added carbon to improve its strength and fracture resistance compared to other forms of iron. Many other elements may be present or added. Stainless steels that are corrosion- and oxidation-resistant t ...

forgings and had

aluminium Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. It has ...

alloy heads. The pistons were of aluminium alloy, with three compression rings and one scraper ring. The connecting rods were of nitrided steel, with divided big ends and

bronze Bronze is an alloy consisting primarily of copper, commonly with about 12–12.5% tin and often with the addition of other metals (including aluminium, manganese, nickel, or zinc) and sometimes non-metals, such as phosphorus, or metalloids such ...

bushes at the little ends. The one piece crankshaft was also formed from nitrided steel and had two main roller bearings and a single ball thrust bearing. The single piece

crankcase In a piston engine, the crankcase is the housing that surrounds the crankshaft. In most modern engines, the crankcase is integrated into the engine block. Two-stroke engines typically use a crankcase-compression design, resulting in the fuel/ ...

was cast from an aluminium alloy. 135 units in all, including B and B2 variants were built.Praha history
Jowett Cars Ltd. of Idle,

Bradford Bradford is a city and the administrative centre of the City of Bradford district in West Yorkshire, England. The city is in the Pennines' eastern foothills on the banks of the Bradford Beck. Bradford had a population of 349,561 at the 2011 ...

in the UK obtained a licence in 1936 to build the Praga B engine, for installation into the licence built Hillson Praga. Immediately after the end of World War II the Praga B2 was on display at the 1946 Paris Air Show.Small engines at Paris Show ''Flight'' 21 November 1946
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Applications (B & B2)

* Alaparma A.M.10 Tucano * AVEX Yakstas Racer Yakstas LV-X095

* de Schelde Scheldemeeuw * de Schelde Scheldemusch * Hillson Pennine * Mignet Flying Flea * Praga E.114/Hillson Praga

Design

Applications (B & B2)

Specifications (B2)

See also

References

Further reading