4-Stroke UAV Engines

Manufacturers of 4-stroke UAV engines and suppliers of four-stroke engines for drones and UAS, including heavy fuel, carburettor and fuel injection engines

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Austars Model

Advanced VTOL & Fixed-Wing UAVs | State-Of-The-Art Technologies for Unmanned & Autonomous Aircraft

Tamilan

Quadcopter Airframes and Complete Drone Solutions for Civilian, Commercial, and Military Applications

INF Inject

Advanced EFI Drone Propulsion Solutions for Commercial & Industrial UAV Platforms

RCV Engines

Heavy Fuel and Gasoline 4-Stroke UAV Engines

Flygas

High-Powered Engines & Propulsion Solutions for Group 4 & 5 UAVs

Vanguard

V-Twin Horizontal Shaft EFI Engines for Drones & UAVs

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Products

Limbach L-2400 UAV EFI Engine

2400cc EFI four-stroke boxer engine with liquid cooling

2400cc EFI four-stroke boxer engine with liquid cooling
... a 2424cc four-stroke electronic fuel injection (EFI) boxer engine designed for UAVs with MTOWs of...
Saito EFI 120

Four-stroke EFI engine with 12,000 ft max altitude

Four-stroke EFI engine with 12,000 ft max altitude
...efficient four-stroke engine that is ideal for a variety of UAV platforms, featuring a power output...
Saito 120

120cc four-stroke UAV engine with highly efficient fuel consumption

120cc four-stroke UAV engine with highly efficient fuel consumption
...'s Saito 120cc UAV engine is based on the proven and reliable Saito four-stroke platform. Created...
RCV DF70 Twin Cylinder UAV Engine

70 cc Multi-Fuel 4-Stroke Engine

70 cc Multi-Fuel 4-Stroke Engine
...gh-performance 4-stroke twin-cylinder UAV engine designed to military specifications for the...
RCV DF35 Single Cylinder UAV Engine

35 cc Multi-Fuel 4-Stroke Engine

35 cc Multi-Fuel 4-Stroke Engine
...for existing 2-stroke engines, providing upgrades in reliability, quality and multi-fuel operation....
GAS418A

135 HP UAV engine for long-range, medium-altitude operations

135 HP UAV engine for long-range, medium-altitude operations
...135 horsepower UAV engine developed for long-range unmanned aircraft operating at medium to high...
GAS418HA

Supercharged four-stroke gasoline engine for high-altitude & MALE UAV applications

Supercharged four-stroke gasoline engine for high-altitude & MALE UAV applications
The GAS418HA is a high-performance four-stroke gasoline engine for Group 4 and Group 5 UAS (unmanned...
GAS418S

Compact four-stroke UAV gasoline engine with versatile installation options

Compact four-stroke UAV gasoline engine with versatile installation options
...y compact four-stroke gasoline engine with low overall weight that is designed to fit into very...
Flygas 912 EFI Supercharged

Upgraded Rotax 912 4-stroke engine for more power, less additional weight, increased load capacity

Upgraded Rotax 912 4-stroke engine for more power, less additional weight, increased load capacity
... Rotax 912 ULS engine completely assembled, bench tested and equipped with the following Flygas...
Vanguard® 29,9 Gross kW EFI/ETC

Vanguard’s most powerful EFI horizontal shaft engine for extreme-duty commercial equipment

Vanguard’s most powerful EFI horizontal shaft engine for extreme-duty commercial equipment
...C BIG BLOCK™ engine represents the peak of Vanguard’s horizontal shaft EFI line, developed...
Vanguard® 27,6 Gross kW EFI/ETC

EFI/ETC-equipped BIG BLOCK™ V-Twin engine for industrial applications

EFI/ETC-equipped BIG BLOCK™ V-Twin engine for industrial applications
...t BIG BLOCK™ engine delivers peak performance for high-power applications in agriculture,... ...... for rugged reliability, this engine maintains efficiency and performance under constant stress....
Vanguard® 24,6 Gross kW EFI/ETC

EFI & ETC-equipped V-Twin engine for high-efficiency, high-demand commercial equipment

EFI & ETC-equipped V-Twin engine for high-efficiency, high-demand commercial equipment
...rizontal shaft engine combines electronic precision and mechanical strength to power through the...
Vanguard® 17,2 Gross kW EFI

EFI-equipped V-Twin engine engineered for fuel-efficient power in commercial equipment

EFI-equipped V-Twin engine engineered for fuel-efficient power in commercial equipment
...rizontal shaft engine combines a robust V-Twin design with advanced Electronic Fuel Injection for... ...ut, and longer engine life with reduced fuel use....

4-Stroke UAV Engines

Sarah Simpson

Updated:

Four-stroke engines are a form of internal combustion engine that are designed in such a way that their power cycle involves four distinct strokes of each piston for one revolution of the engine’s crankshaft – these strokes are known as intake, compression, combustion and exhaust.

Two-stroke engines Vs four-stroke UAV engines

Saito 120cc four-stroke UAV engine by Innoflight Technology

Saito 120cc four-stroke UAV engine by Innoflight Technology

Compared to two-stroke engines, four-stroke drone engines are typically bigger and heavier, making them more suitable for larger UAVs (unmanned aerial vehicles). With more moving parts, they require more complex maintenance. However, they are more fuel-efficient and produce lower emission levels, making them more environmentally friendly. They also utilize separate lubrication systems, thus doing away with the need to pre-mix engine oil into the fuel.

Multi-cylinder engine design

Four-stroke engines may be designed as single-cylinder engines, or have two or more cylinders. Multiple-cylinder engines take up more space and weight and thus may not be suitable for the smallest UAVs, but provide more power per stroke and smoother output. Multi-cylinder engines may also feature a “limp home” mode that allows the UAV to keep flying when a cylinder has been damaged.

Cooling methods

Four-stroke engines may utilize a number of different cooling methods:

RCV DF70 Twin-Cylinder 4-Stroke UAV Engine by RCV Engines

RCV DF70 Twin-Cylinder 4-Stroke UAV Engine by RCV Engines

  • Air cooling uses ambient airflow to reduce excess heat, and is the simplest but least thermally efficient method.
  • Liquid cooling provides better performance, but requires additional complex mechanisms that increase weight and maintenance requirements.

Four-stroke UAV engines may run on gasoline, methanol, or heavy fuels such as Jet A, Jet A1, JP-5 and JP-8. Heavy fuel operation is becoming more common as a requirement for military UAV engines, as many armed forces operate a “one fuel” policy requiring all vehicles, aircraft and equipment to run off the same fuel type in order to simplify logistics.

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