The UMS 5-Cylinder 100cc Petrol Radial Engine is a compact, lightweight 4-stroke radial engine delivering authentic scale appearance, smooth operation, and dependable performance. Designed for smaller scale and lightweight radial projects, it offers true radial sound and engineering precision in an easy-to-install, ready-to-run package.

Product Description

The UMS 5-Cylinder 100cc Radial Engine is engineered for builders who demand visual authenticity and refined mechanical performance in compact scale aircraft. Its classic 5-cylinder radial layout closely replicates full-size aviation engines while delivering smooth, balanced power suitable for detailed scale and vintage RC aircraft.

With a 100cc displacement, this engine is ideal for lighter warbirds, vintage models, and scale aircraft where realism and weight efficiency are critical. Supplied ready to run, it includes an exhaust collector ring, electronic ignition system, spark plugs, and a sturdy engine mount, ensuring a straightforward installation and reliable operation from the first start.

Precision manufacturing is at the heart of this engine. All major components are CNC-machined from aluminium or bar stock, maintaining tight tolerances for consistent performance. Aircraft-grade alloy cylinder heads and crankcases provide strength and durability without unnecessary weight. A heavy-duty double-bearing crankshaft ensures smooth running and reduced vibration.

Internally, billet aluminium pistons with hardened steel rings deliver excellent sealing and longevity, while hard-chromed and lapped cylinder bores reduce wear and enhance efficiency. Hardened steel camshafts ensure accurate valve timing and long-term reliability under sustained operation.

Designed to operate on 87–110 octane petrol with a 32:1 fuel-to-oil mixture, the UMS 5-100cc radial engine combines traditional radial character with modern engineering, making it a perfect choice for scale builders seeking realistic sound, refined performance, and dependable 4-stroke power.

Key Features

• 5-cylinder 4-stroke radial engine with authentic scale appearance

• 100cc displacement ideal for lightweight scale aircraft

• Ready-to-run package including ignition, plugs, exhaust collector ring & engine mount

• Precision CNC-machined aluminium and bar stock construction

• Aircraft-grade alloy cylinder heads and crankcases

• Heavy-duty double-bearing crankshaft for smooth operation

• Billet aluminium pistons with hardened steel piston rings

• Hard-chromed and lapped cylinder bores for durability

• Hardened steel camshafts for long-term reliability

• Integrated choke and throttle bellcranks for easy installation

• Compatible with 87–110 octane petrol (32:1 fuel mix)

Perfect For

• Lightweight scale RC warbirds and vintage aircraft

• Smaller radial-engine scale projects

• Builders prioritising realism with reduced engine weight

• Smooth, reliable 4-stroke petrol power

• Advanced hobbyists and precision scale modellers

Specifications

Engine Type: 4-Stroke
Cylinders: 5 (ABC Type)
Displacement: 100cc
Bore: 28mm
Stroke: 32mm
Approx. Thrust: 12.5kgf @ 24×10 SEP prop
RPM Range: 1,000 – 6,000
Weight (with silencer & ignition): Approx. 3.6kg
Engine Diameter: 240mm
Engine Length: 162mm
Recommended Propellers:

• 2-Blade 24×8

• 2-Blade 24×10
  

Muffler Type: Collector Ring
Spark Plug: 1/4-32
Carburettor: Walbro
Fuel Type: Petrol (87–110 octane, 32:1 mix)

Why Buy from Probuild Aircraft

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