New O.S. Speed Shimo Edition R21, 21XZ-B SpecII combo set, and Max-12TG Ver.III

0 Jan. 28, 2016, 3:50 p.m.

By Aaron Waldron
LiveRC.com

New from O.S. Engines:
www.os-engines.co.jp

O.S. Engine has introduced three new engines, covering all ends of the brand’s product line.

The Speed R21 Shimo Edition is a complete package that will be sold in limited quantities to celebrate Takaaki Shimo’s runner-up finish at the 2015 IFMAR 1/8-Scale On-Road Worlds. Just like the engine Shimo ran in Brazil, this special edition engine comes fitted with a 8.0mm silver carb venturi, special 2x.1mm and 1x.15mm head shims, a carburetor spacer to increase mid-range torque, and a steel rear bearing Shimo prefers when running the carb spacer. The crankcase features a special silver logo, and the cooling head is also silver with an updated logo. A handmade T-2080SC exhaust system is included.

Specs:
Displacement: 3.49cc (0.213 cu.in.)
Bore: 16.08mm (0.633 in.)
Stroke: 17.20mm (0.677 in.)
Output: 2.8 PS (2.76 HP) @ 33,000 rpm
Practical rpm range: 4,000-45,000 rpm
Weight: 340g (11.99 oz) (engine body)

Though the B2101 is the flagship O.S. Speed engine for off-road, the Japanese brand recognized the popularity of the previous model 21XZ-B SpecII engine among certain racers and have introduced a combo including a polished T-2060SC WN exhaust system.

Specs:
Displacement: 3.46cc
Bore: 16.27mm
Stroke: 16.8mm
Output: 2.65 PS @ 34,000 rpm
Practical rpm range: 4,000-42,000 rpm
Weight: 355g (engine body)

Finally, the new Max-12TG Ver.III sports on-road racing engine is an intermediate-level offering which has been refined for smooth acceleration. The aluminum cooling head has been lightened to lower the vehicle’s center of gravity, and a 12D2 carburetor and new head button that accepts only turbo glow plugs have been fitted.

Specs:
Displacement: 2.1cc
Bore: 13.8mm
Stroke: 14.0mm
Output: 0.9 ps @ 30,000 rpm
Practical rpm range: 5,000-32,000 rpm
Weight: 216g (engine body)