O.S. Engine OS-13911 Speed 21 VZ-B-V Spec II Limited Race Edition  [OS-13911]

Track-focused design of the O.S. Engine OS-13911

The O.S. Engine OS-13911 is engineered for precision and repeatable results on track and rougher courses. Focused on both power and consistency, this motor suits drivers who want a reliable, high-revving platform for competition or weekend practice.

Broad usable RPM for versatile tuning

With a displacement of 3.66cc and peak output of 2.5ps at 34,000 RPM, the OS-13911 covers a practical range from 3000~40000 RPM. That span helps tuners extract usable performance whether the track calls for torque through corners or high speed on straights.

Compact mass with solid durability

At 349g, this engine keeps weight low to aid handling and acceleration. The 16.6mm bore and 16.0mm stroke offer a balanced combustion character that supports efficient running and consistent throttle response.

Practical advantages for club racers

What makes the OS-13911 useful in competition is its predictable behaviour at higher revs, which reduces surprises during long runs and helps drivers focus on setup and driving lines.

For enthusiasts who value a steady, tunable engine for both on-road and off-road formats, the O.S. Engine OS-13911 is a practical choice.