3W International

Heavy-Fuel and Gas Engines for Unmanned Aircraft

3W International

3W International (3W) manufactures next-generation heavy-fuel (HF) and gas engines for the unmanned aerial vehicle (UAV) industry.

The company's engines are designed for unmanned fixed wings, helicopters and hybrid unmanned aerial vehicles (UAV).

Custom-made UAV propulsion systems for maximum power

3W engines can be supplied with a carburettor or an electronic injection, and can be customised based on the used aircraft and fuel types, or the necessary performance parameters.

3W's complete propulsion systems consist of unpack, install and take off, and the engines can be provided with all auxiliary systems.

Wankel rotary hybrid cycle engines for field operation payloads

3W's Wankel Rotary UAV Engine is a compact hybrid cycle engine, which is lightweight and provides a high power-to-weight ratio, increasing field operation payloads.

An additional 15KW depend on store capacity with the hybrid boost power, which simplifies lift-off or acceleration. The 3W-180 SRE can run on gas or HF, and is offered with a standard manifold or high-pressure injection (HPI). Engine cooling is guaranteed by water cooling of the housing and oil cooling of the rotor (active cooling).

Single and multiple cylinder engine ignitions

3W supplies one-cylinder, two-cylinder and four-cylinder engines. All two-stroke engines measure 55cm and are delivered as a twin-spark (TS) version, which increases safety and reliability.

Both ignitions operate separately and general operational behaviour is quieter as the engine runs at a lower idle. When one ignition stops, the second ensures that the engine continues to run with slightly reduced rotational speed.

Long-term tests for aircraft durability verification

3W offers an extensive variety of long-term tests that are adapted and performed individually according to client requests using state-of-the-art measuring instruments.

A wide range of long-term tests are required, from the 50-hour test for microlight aircraft to tests of up to 200 hours.

Muffler systems for aircraft engine development

3W mufflers use turbine wheels that are permanently installed in a cylinder. The individual fins mounted on the wheels are organised / configured in defined angles and arranged in opposite directions, depending on the angle, which smoothes out the exhaust gas' sound wave.

Time-between-overhauling (TBO) for extreme engine propulsion

3W specifies TBOs between 400-600 hours, according to engine maintenance and the conditions of use.

The total number of hours will depend on the revolutions per minute (RPM) range and applications. It is possible to achieve maximum performance if engines are driven at moderate speeds and serviced at regular intervals.

About 3W International

German-based 3W International has more than 35 years of experience in designing, manufacturing and testing two-stroke engines.

3W comprises innovative production, tradition and technical expertise to supply high-quality gas engines. The company ensures continual and permanent quality control, from manufacturing and calibration, purchasing, prototyping and R&D to in-time delivery.

Contact Details

3W International GmbH
Hollerstraße 12
61350 Bad Homburg vor der Höhe
+49 6172 80 89 34 0

Available White Papers


Multi-Fuel Engine Product Portfolio 06 September 2017 In 2007, 3W International began to research and develop its first heavy fuel engines. Several developments were made and tested until the R&D department decided on the final engine design.


Gas Engines Product Portfolio 09 August 2017 With more than 30 years of experience in developing, manufacturing and testing 2-stroke engines, 3W has designed and patented the newest generation of gas engines for the unmanned aerial vehicle (UAV) industry.