Jacobs R-755 Radial Engine

Jacobs R-755 Radial Engine


Part of Harry Kraemer's Transportation Museum.

Click here for a slideshow of other vehicles in the collection

In 1903–1904 Jacob Ellehammer used his experience constructing motorcycles to build the world's first air-cooled radial engine, a three-cylinder engine which he used as the basis for a more powerful five-cylinder model in 1907. This was installed in his triplane and made a number of short free-flight hops

The Jacobs R-755 (company designation L-4) is a seven-cylinder, air-cooled, radial engine for aircraft manufactured in the United States by the Jacobs Aircraft Engine Company. The R-755 was first run in 1933 and was still in production in the 1970s.

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Click here for pictures of the Flymall team removing the engine from the hangar

Click here for more info on Jacob Ellehammer

Click here for some info on a Elleham motorcycle

Click here for Harry's radial engines tech tip page on the Flymall

Not all radial engines are a odd number of cylinders, see below.

Click here for info on another rare 6 cylinder radial engine in the collection

The Anzani is a rare 10 cylinder radial engine.
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Anzani 10 Cylinder Radial Engine

Here's some info on a Anzani 6 cylinder radial engine.

It was an Anzani engine which powered the tiny monoplane in which M. Bleriot made the memorable first flight across the English Channel on 25 July 1909. The engine had three cylinders and provided 25hp. The 6 cylinder engine on display is a later version (circa 1914) and is virtually two 3-cylinder engines sharing a common crankcase. The cylinder bores are 4.14in, stroke 4.73in, 1,300rpm. Power is 50/60hp. In all the early Anzani engines the cylinders are slightly off-set or desaxe, i.e. the cylinder axis does not pass through that of the crankshaft. The principle object being to diminish the obliquity of the connecting rod to the piston axis during the working stroke, thus reducing piston friction, heating and wear. During the early period, Anzani produced engines of 3, 6, 10 and 20 cylinders, all radial, in the range 30 to 200hp.

Anzani engine

Here are some 3 wheelers with radial engines in them

Equipment Specifications
Detailed Information
Detailed Description
The Jacobs Aircraft Engine Company was formed in 1926 in Philadelphia. Later the company moved to Pottstown, Pennsylvania after purchasing the machine workshop of the Light Manufacturing and Foundry Company.
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