The UMS 9-Cylinder 115cc Petrol Radial Engine delivers true nine-cylinder radial realism in a compact, precision-engineered 4-stroke package. Designed for scale aircraft builders who demand authentic appearance, smooth operation, and long-term reliability, this ready-to-run petrol radial offers balanced performance and unmistakable radial sound.

Product Description

The UMS 9-115cc Radial Engine represents the pinnacle of compact multi-cylinder radial engineering. Featuring a classic 9-cylinder configuration, it delivers exceptional visual authenticity while providing smooth, well-balanced 4-stroke power across the RPM range.

With a 115cc displacement, this engine is ideal for scale warbirds, vintage aircraft, and museum-quality replica builds where realism and smooth performance are equally important. Supplied ready to run, it includes an exhaust collector ring, electronic ignition system, spark plugs, and a durable engine mount for straightforward installation.

Manufactured using precision CNC-machined aluminium and bar stock components, the engine maintains tight tolerances for consistent performance. The aircraft-grade alloy cylinder heads and crankcases provide strength while keeping weight optimised for scale flight applications.

Internally, a heavy-duty double-bearing crankshaft enhances stability and longevity under sustained operation. Billet aluminium pistons fitted with hardened steel rings operate within hard-chromed and lapped cylinder bores, improving wear resistance and combustion efficiency. Hardened steel camshafts ensure accurate valve timing and dependable long-term performance.

Designed to run on 87–110 octane petrol with a 32:1 fuel-to-oil mixture, the UMS 9-115cc radial engine provides dependable starting, smooth throttle response, and authentic radial sound for discerning aviation enthusiasts and professional builders.

Key Features

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

• 115cc displacement delivering smooth, balanced power

• Ready-to-run package including ignition, plugs, 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 durability and stability

• Billet aluminium pistons with hardened steel rings

• Hard-chromed and lapped cylinder bores for reduced wear

• Hardened steel camshafts for reliable valve timing

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

Perfect For

• Scale RC warbirds

• Vintage and golden-era aircraft replicas

• Museum-quality display and flying models

• Builders seeking authentic 9-cylinder radial sound

• Advanced hobbyists and professional scale modellers

Specifications

Engine Type: 4-Stroke
Cylinders: 9 (ABC Type)
Displacement: 115cc
Bore: 25.1mm
Stroke: 26.0mm
Approx. Thrust: 12kgf @ 24×12 prop
RPM Range: 1,000 – 5,500
Weight (with silencer & ignition): Approx. 4.6kg
Engine Diameter: 260mm
Engine Length: 170mm
Recommended Propellers:

• 2-Blade 24×10

• 2-Blade 24×12

• 2-Blade 26×10

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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