The UMS 5-Cylinder 55cc Petrol Radial Engine delivers authentic radial appearance, smooth 4-stroke performance, and dependable engineering in a compact, lightweight format. Designed for smaller scale aircraft, this ready-to-run petrol radial offers realistic sound, refined machining, and long-term durability.

Product Description

The UMS 5-Cylinder 55cc Radial Engine is the smallest in the UMS 5-cylinder radial range, offering true radial realism in a compact and lightweight package. Perfect for detailed scale models and vintage aircraft builds, it combines authentic sound and appearance with modern manufacturing precision.

With a 55cc displacement, this engine provides reliable and efficient power for lightweight scale aircraft where balance and weight are critical. Supplied ready to run, it includes an exhaust collector ring, spark plugs, electronic ignition system, and a sturdy engine mount for straightforward installation.

All major components are CNC-machined from aluminium or bar stock, ensuring accuracy, repeatability, and durability. The aircraft-grade alloy cylinder heads and crankcases provide strength while maintaining an excellent strength-to-weight ratio.

A heavy-duty double-bearing crankshaft ensures smooth operation and extended service life. Billet aluminium pistons fitted with hardened steel rings operate within hard-chromed cylinder bores, reducing friction and enhancing wear resistance. Hardened steel camshafts ensure reliable valve timing and long-term operational stability.

Designed to operate on 87–110 octane petrol with a 32:1 fuel-to-oil mixture, this compact radial engine provides dependable 4-stroke performance and authentic scale character for discerning builders.

Key Features

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

• 55cc displacement ideal for lightweight and smaller scale aircraft

• 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 smooth operation

• Billet aluminium pistons with hardened steel rings

• Hard-chromed cylinder bores for durability and reduced wear

• Hardened steel camshafts for reliable valve timing

• User-friendly choke and throttle bellcranks

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

Perfect For

• Smaller scale RC warbirds

• Vintage and classic aircraft builds

• Lightweight radial engine applications

• Builders seeking authentic radial sound

• Precision scale modelling projects

Specifications

Engine Type: 4-Stroke
Cylinders: 5 (ABC Type)
Displacement: 55cc
Bore: 23.7mm
Stroke: 25mm
Approx. Thrust: 7.5kgf @ 20×8 SEP prop
RPM Range: 1,000 – 6,000
Weight (with silencer & ignition): Approx. 2.35kg
Engine Diameter: 201mm
Engine Length: 142mm
Recommended Propellers:

• 2-Blade 17×8

• 2-Blade 17×10

• 2-Blade 17×12

• 2-Blade 18×6

• 2-Blade 18×8

• 2-Blade 20×8

Muffler Type: Collector Ring
Spark Plug: 1/4-32
Carburettor: UMS T2
Fuel Type: Petrol (87–110 octane, 32:1 mix)

Why Buy from Probuild Aircraft

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