3W International

Gas and Heavy-Fuel Engines for Unmanned Aerial Systems and Vehicles

3W International

3W International (3W), manufacturer of two-stroke gas engines, develops and patents next-generation heavy-fuel (HF) engines for unmanned aerial systems (UAS). All HF-engines can run with JET A-I, JP-5, JP-8, mix ration 2% Aspen Oil 0.1% Diesel Valve Cleaner.

3W engines are used in unmanned fixed wings, helicopters and hybrid unmanned aerial vehicles (UAV). HF-Wankel engines and the sub-systems, are also part of the product line.

Single and multiple cylinder engines for UAS

3W offers one-cylinder, two-cylinder and four-cylinder engines.

All two-stroke engines measure 55cm and are delivered as a twin-spark (TS) version. The safety and reliability increase in both single-cylinder and multiple-cylinder engines when using the TS cylinder.

Both ignitions work independently and the engine runs at a quieter yet lower idle. When one ignition fails, the second ensures that the engine continues to run with slightly reduced rotational speed.

Rotary UAV engine for field operations

3W's Wankel Rotary UAV engine is a hybrid cycle engine with a compact design.

The lightweight, four-stroke rotary engine (SRE) offers a high power-to-weight ratio, allowing an increased payload in field operations. With the hybrid boost power, an additional 15KW depend on store capacity, which simplifies lift-off or acceleration.

The 3W-180 SRE can run with gas or HF. Therefore, 3W offers a standard manifold or a high-pressure injection (HPI).

The cooling of the engine is guaranteed by water cooling of the housing and oil cooling of the rotor (active cooling).

Customised military engines for high-powered applications

All standard engines by 3W can be tailored according to customer specifications based on the used aircraft type, the required performance parameters or the fuel types.

They can be available with all auxiliary systems up to propellers and 3W's complete propulsion systems consist of unpack, install and take off.

Long-term tests to verify vehicle durability

3W offers a wide variety of long-term tests, which are adapted and performed individually according to client requests using sophisticated measuring instruments.

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

Muffler systems for engine development

3W mufflers use a variant of turbine wheels that are installed permanently in a cylinder.

The individual fins mounted on the wheels are queued up in defined angles, where they are arranged in opposed directions depending on the angle. This arrangement smooths the exhaust gas' sound wave.

Time-between-overhauling (TBO) for ultimate engine performance

3W specifies TBOs of up to 400-600 hours, depending on the operational conditions and the maintenance of the engine. The number of hours will depend on the areas of use and the revolutions per minute (RPM) range. Maximum performances are possible if engines are driven at moderate speeds and serviced at regular intervals.

About 3W International

3W International is a German family business with more than 35 years of experience in designing, manufacturing and testing two-stroke engines.

The company comprises technical expertise, long-term experience, tradition and state-of-the-art production to produce high-quality gas engines.

3W guarantees constant and permanent quality control, from R&D, prototyping, purchasing, manufacturing and calibration 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.