This is a Motorlet M-701 centrifugal-flow turbojet engine that is mounted to a test run trailer which includes everything needed to run the engine, including a control panel, fuel tank, and battery system.
Thousands of these engines were built during their production run, and as a result, parts can still be sourced relatively easily from Eastern European sources. With close to 2,000 lbf of thrust at takeoff, this 800 lb engine has most recently been run on diesel fuel.
With close to 2,000 lbf of thrust at takeoff, this 800 lb engine has most recently been run on diesel fuel.
The Motorlet M-701 Turbojet Engine
The Motorlet M-701 is a Czechoslovakian centrifugal-flow turbojet engine that was developed in the early 1950s by the Motorlet company, based in Prague. It was the first locally-developed jet engine built in Czechoslovakia and it played a major role in the country’s post-war aviation industry – most importantly as the powerplant for the Aero L-29 Delfin jet trainer.
The design of the M-701 began in 1952, the project was driven by the need for a reliable, domestically-produced jet engine to support the growing (and increasingly important) Czechoslovakian aerospace sector, which at the time relied heavily on Soviet technology. Many believed too heavily.
Motorlet was previously known as Walter Aircraft Engines – the company had ample experience building piston aircraft engines but transitioned to jet propulsion due to a government directive. The M-701 was based on established centrifugal-flow turbojet designs from the early jet age, particularly those like the British Rolls-Royce Derwent.
Technically, the M-701 is a single-spool centrifugal-flow turbojet with a relatively simple design and a focus on longevity and dependability – intended to ease both manufacturing and maintenance issues. The engine uses a centrifugal compressor, an annular combustion chamber, and a single-stage axial turbine. It produces approximately 1,960 lbf of thrust for takeoff, with a little less for flight, closer to 1,760 lbf.
The most important use of the M-701 was in the Aero L-29 Delfin, a jet trainer developed in the late 1950s and selected as the standard trainer aircraft for Warsaw Pact air forces.
This M-701 has been fitted to a run trailer, which contains all the key things it needs to run, like a fuel tank, batteries, and a control panel.
Over 3,600 L-29s would be built, and nearly all were powered by the M-701, making it one of the most prolifically produced jet engines of its type from the period.
The Motorlet M-701 Engine Shown Here
The Motorlet M-701 turbojet engine you see here was previously modified to run on biofuel, it was then used as a proof-of-concept test engine for GreenFlight International in 2008.
GreenFlight was a research and development firm developed to make economically viable biofuels derived from algae a viable alternative to modern jet fuels that are all derived from fossil fuels. In 2007 they became the first to fly a jet aircraft powered entirely by biofuel – proving the concept.
This specific Motorlet M-701 flew from Texas to Florida fueled only by vegetable oil, presumably in an Aero L-29 Delfin, though this isn’t mentioned.
The Motorlet M-701 turbojet engine you see here was previously modified to run on biofuel, it was then used as a proof-of-concept test engine for GreenFlight International in 2008.
This M-701 has been fitted to a run trailer, which contains all the key things it needs to run, like a fuel tank, batteries, and a control panel. The engine was last run in 2018 on diesel fuel, but there is no mention in this listing about its current level of operability.
The engine is being offered for sale out of Blenheim, Ontario, Canada with no reserve and a bill of sale. If you’d like to read more about it or register to bid you can visit the listing here.
Images courtesy of Bring a Trailer
Articles that Ben Branch has written have been covered on CNN, Popular Mechanics, Smithsonian Magazine, Road & Track Magazine, the official Pinterest blog, the official eBay Motors blog, BuzzFeed, Autoweek Magazine, Wired Magazine, Autoblog, Gear Patrol, Jalopnik, The Verge, and many more.
Silodrome was founded by Ben back in 2010, in the years since the site has grown to become a world leader in the alternative and vintage motoring sector, with well over a million monthly readers from around the world and many hundreds of thousands of followers on social media.