RCGF 31cc Twin Cylinder Gas Engine for RC Airplanes 3.7HP Small Scale Smooth Power
Hero Section: The "Jewel" of Your Hangar
Usually, to enjoy the mesmerizing sound and vibration-free performance of a twin-cylinder engine, you have to build a giant 50cc or 100cc aircraft. Not anymore. The RCGF 31cc Twin is a mechanical masterpiece that brings the prestige of a "boxer" engine to your 30cc-class sport planes and scale warbirds. Imagine the look on your friends' faces when you pop the cowl on a 70-inch wingspan plane to reveal two cylinders. It’s not just about flying; it’s about the joy of owning a precision-engineered machine that sounds as good as it looks.
Why Choose the RCGF 31cc Twin?
- Small Size, Big Attitude: This is one of the smallest twin-cylinder gas engines on the market. It allows you to upgrade your standard 30cc planes (like a Piper Cub, Cessna, or Stick) from a shaking single-cylinder to a smooth-running twin without major airframe modifications.
- Vibration Cancellation: The horizontally opposed design naturally cancels out the harsh vibrations that plague single-cylinder engines. This means your airframe lasts longer, screws stay tight, and your flight video footage is smoother.
- Acoustic Perfection: Forget the high-pitched whine of small engines. The RCGF 31cc produces a unique, lower-frequency purr that adds a layer of realism to your scale flights.
- Reliability Built-In: Equipped with a genuine Walbro carburetor, this engine solves the "hard to start" issues often found in smaller gas engines. It offers consistent fuel metering and a reliable idle.
Technical Highlights: Engineering Excellence
- Precision Crankcase: The crankcase is CNC machined from high-grade aircraft aluminum, ensuring perfect alignment of the cylinders. This reduces friction and heat, contributing to the engine's longevity.
- Smart Ignition: The included DC-CDI system features automatic timing advance. It adjusts the spark based on RPM, ensuring a steady idle at 2000rpm and a linear power delivery up to the 7800rpm redline.
- Efficient Cooling: Despite its compact size, the cylinders feature deep cooling fins. Combined with the air-cooled design, it manages heat effectively, even inside tight cowlings.
Specifications
- Model Type: 2-Stroke Twin Cylinder Piston Valve Gasoline Engine
- Displacement: 31cc (1.89 cu in)
- Configuration: Horizontally Opposed Twin (Boxer)
- Bore x Stroke: 1.26 in (32mm) x 0.77 in (19.6mm)
- Performance: 3.7HP / 7800rpm
- Idle Speed: 2000rpm
- Static Thrust: 17.2 lb (7.8 kg) @ 328 ft (100m) altitude
- Static Thrust: 15.3 lb (6.9 kg) @ 5900 ft (1800m) altitude
- Carburetor: Walbro
- Ignition: DC-CDI (Computer Controlled Auto Advance)
- Power Supply: 6-14V
- Spark Plug: 2 x NGK-CM6
- Lubrication Ratio: 30/1 (Gasoline/Oil)
- Suggested Propellers: 18 x 8, 18 x 10, 19 x 8, 20 x 8
- Engine Weight: 2.04 lb (927g)
- Total Weight: 2.9 lb (1300g) approx. (Including Mufflers and Ignition)
Usage Scenario: The Scale Sunday
It’s a relaxing Sunday morning. You aren't looking to do violent 3D stunts; you want to fly gracefully. You fuel up your 1/4 scale Piper Cub. The RCGF 31cc starts with a gentle flip. The sound is distinct—a soft, rhythmic hum. As you taxi out, the plane doesn't rattle. You take off, and the engine pulls the plane with authority but without the noise pollution. It’s a gentleman’s engine, perfect for pilots who appreciate finesse and mechanical beauty over brute force.
Important Tips from the Expert
- Propeller Selection: An 18x8 propeller is the standard for break-in and general flying. For more speed, you can step up to an 18x10 once the engine is broken in.
- Installation: Since this is a twin, it is wider than a single cylinder. Please measure your cowl width carefully. You may need to cut cutouts for the spark plug caps, which often looks very cool on scale planes!
- Break-In: Small twins have tight tolerances. Run the first gallon of fuel with a high-quality synthetic oil at 30/1 and avoid overheating.
Customer Support
We are passionate about engines and are here to help you with your build. If you have questions about fitment or tuning, please contact us: service@helloworld7.com
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