O.S. SPEED R21GT2 GT Engine (OSMG3000)

OS Speed R21GT2 GT Engine is a high-performance RC powerplant designed for GT-class cars, delivering smooth power and efficient operation. It builds on the smooth feel and good fuel efficiency of the previous model while sharpening mid- and low-speed performance through a revised crankshaft counterbalance. A redesigned inner head improves idling, and an inner head O-ring helps reduce vibration and boost dust resistance. The outer head is lighter, with machined cooling fins to aid heat management.

Notable technical details include a crankshaft with two tungsten counterweights to optimize mass balance, a redesigned inner head that enhances idle performance, and a lighter outer head with machined fins. The carburetor is a dual-adjustment type with a 7.0 mm venturi for precise tuning, and the engine features five scavenging ports and three exhaust ports to meet IFMAR regulations. A combo set is available that pairs the engine with a tuned silencer and a compatible manifold for enhanced overall performance.