The UMS 7-Cylinder 260cc Petrol Radial Engine delivers true multi-cylinder radial realism, smooth 4-stroke power, and exceptional engineering precision. Designed for large-scale aircraft, this ready-to-run petrol radial combines authentic appearance, balanced performance, and long-term reliability.

Product Description

The UMS 7-Cylinder 260cc Radial Engine is engineered for serious scale builders who demand both visual authenticity and high-performance output. Its classic 7-cylinder radial configuration replicates the look and sound of full-size aviation engines while providing smooth, balanced operation across the RPM range.

With a substantial 260cc displacement, this engine is ideal for large-scale warbirds, vintage aircraft, and detailed replica projects requiring reliable torque and strong pulling power. Supplied ready to run, it includes an exhaust collector ring, electronic ignition system, spark plugs, and a robust engine mount for straightforward installation.

All primary components are precision CNC-machined from aluminium and bar stock, ensuring tight tolerances and consistent performance. The aircraft-grade alloy cylinder heads and crankcases provide strength while maintaining optimal weight balance for large airframes.

Internally, a heavy-duty double-bearing crankshaft enhances smoothness and durability under sustained loads. Billet aluminium pistons fitted with hardened steel rings operate within hard-chromed and lapped cylinder bores, reducing friction and increasing longevity. Hardened steel camshafts ensure accurate valve timing and dependable long-term reliability.

Designed to run on 87–110 octane petrol with a 32:1 fuel-to-oil mixture, the UMS 7-260cc radial engine provides dependable 4-stroke performance, authentic radial sound, and commanding scale presence for demanding aviation enthusiasts.

Key Features

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

• 260cc displacement delivering strong, smooth 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 stability and durability

• Billet aluminium pistons with hardened steel rings

• Hard-chromed and lapped cylinder bores for wear resistance

• Hardened steel camshafts for reliable valve timing

• Integrated choke and throttle bellcranks for easy setup

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

Perfect For

• Large-scale RC warbirds

• Vintage and golden-era aircraft replicas

• High-end scale builds

• Builders seeking authentic 7-cylinder radial sound

• Advanced hobbyists and professional scale modellers

Specifications

Engine Type: 4-Stroke
Cylinders: 7 (ABC Type)
Displacement: 260cc
Bore: 35.7mm
Stroke: 37.0mm
Approx. Thrust: 25.4kgf @ 33×14 prop
RPM Range: 1,000 – 5,000
Weight (with silencer & ignition): Approx. 8.0kg
Engine Diameter: 328mm
Engine Length: 215mm
Recommended Propellers:

• 2-Blade 32×12

• 2-Blade 32×14

• 2-Blade 33×14
  

Muffler Type: Collector Ring
Spark Plug: CM6
Carburettor: Walbro
Fuel Type: Petrol (87–110 octane, 32:1 mix)

Why Buy from Probuild Aircraft

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