This is the Dynamite Mach 2 .21 SG nitro buggy engine. Dynamite's Mach 2 series engine line ignites the industry with the .21 SG nitro engine. Known for explosive power, reliability and all-out performance, Dynamite engines are becoming the engine of choice for many RC sport racers. The 13mm turbo ported crankshaft along with the ABC 6-port piston and sleeve allow this engine to deliver superior horsepower, high torque and extreme efficiency matched only by engines at much higher price points. The Dynamite .21 SG incorporates the technology and design advances developed from the Dynamite Platinum .21 XP in a sport version. Whether you're upgrading your existing nitro vehicle or looking to build a competitive racer, look no further, the Dynamite .21 SG engine has everything you need to be successful in the backyard or on the track. Key Features: 13mm turbo ported crankshaft 2-needle carburetor ABC 6-port piston and sleeve Knife edged connecting rod Specifications: Type: 2-stroke Displacement: .21 Bore: 16.27mm Stroke: 16.75mm Engine (Only) Weight: 310 g RPM Range: up to 33,000 HP: 2.3 Front Bearing Size: 7 x 19 x 6 Rear Bearing Size: 13 x 24 x 6 Cylinder Type: ABC # of Ports: 6 + 1 Carb Type: 2-needle slide Crank Type: SG