The O.S. Speed R21 “EURO” II is a premium 3.5cc (.21) nitro on-road racing engine designed for 1/8 competition cars and demanding racers who want precise power delivery and consistent performance over every run. Based on the proven R21 platform, the crankshaft counterbalance has been refined to improve low and mid-range power output, delivering a smoother and more controllable driving feel.

This results in strong corner-exit drive, reliable throttle response and clean RPM behavior—ideal for technical tracks where traction and controllable power matter most. The R21 EURO II is built for competitive racing and delivers the performance and quality O.S. Speed is known for.

Note: Engine only. Exhaust system and manifold are typically sold separately depending on the version/set.

Key Features

• High-performance 3.5cc (.21) nitro on-road engine for 1/8 racing
• EURO II update with revised crankshaft counterbalance
• Improved low/mid power for consistent lap times
• Smooth, controllable throttle response and power delivery
• Designed for serious competition use

Box Contents

• O.S. Speed R21 “EURO” II engine (1DR00)

Required to Run

• Suitable 1/8 on-road exhaust pipe and manifold (depending on your setup)
• Air filter / filter oil (track dependent)
• Glow plug suitable for your tuning
• Nitro fuel
• Starter box or compatible starting system
• Clutch and flywheel (chassis dependent)