This is the O.S. Speed R21GT engine for the 1/8th GT on-road classes. Designed with the forthcoming 1/8th GT IFMAR World Championship in mind, the engine builds on the proven R2101 crankcase which was refined as was the 5+3 ports liner and piston to meet current IFMAR rules. The newly designed crankcase features a DLC coating for wear while the updated cooling head design ensures optimised heat dissipation under the large GT body shells. The engine is rounded out by the newly designed 22E (B) GT carburettor and it comes with a 7mm venturi insert, again to meet IFMAR requirements.
Displacement: 3.49 cc
Intake ports: 5-port
Exhaust port: 3-port
Practical RPM range: 4,000 – 42,000 rpm
Max. power output: 2.65 ps / 2.61 hp / 34,000 rpm