February 8, 2023

O.S. SPEED R2105 .21 Onroad Engine

O.S. Engines has released the latest version of its 1:8 Onroad World Championship winning engine, the R2105.  The O.S. SPEED R21 series took the Mugen of Shoki Takahata to the World title in the US at the end of 2019 and in a year that he will try to defend that title in Japan at the Infinity International RC Speedway, the Japanese engine manufacturer has redesigned most of the parts that make up the R2105.  To increase torque on high-grip track surfaces, a newly designed 9-port sleeve is adopted.  O.S. SPEED’s traditional DLC coated crankshaft delivers linear power from low to top by changing the counter balance.  The outer head has been mirror finish and by clear coat from the conventional colour to a silver head base has been adopted.  By adopting a thrust plate made out of steel, wear due to interference between the connecting rod and the cover plate during rotation is reduced and engine life is improved.

R2105 Spec
Displacement: 3.49 cc / 0.213cu.in.
Bore: 16.08mm / 0.633 in.
Stroke: 17.20mm / 0.677 in.
Output: 2.80 ps / 2.76 hp / 35,000 r.p.m.
Practical RPM range: 4,000-45,000 r.p.m.
Engine weight: 345.0g / 12.17 oz.
Includes: Reducer(8.5mm RED)/T-RP7 glow plug/Exhaust seal ring(1pc)/ Dust cap set (3mm, 16mm, 18mm 1pc each)

Source: O.S. Engines [os-engines.co.jp]


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