O.S. Speed B21 AD3 Adam Drake 3 Competition .21 Nitro Engine w/Adam Drake Break In

The O.S. Speed B21 AD3 Adam Drake 3 Competition .21 Nitro Engine is the  latest evolution of this potent racing engine. Designed in collaboration  with the legendary Adam Drake this AD3 edition features several updates  and improvements over the already competitive B21 engine platform. The  AD3 uses an updated crankcase inner design for linear power making the  transition from low to middle to high speeds almost seamless. Adding to  this is an updated backplate with a steel lining reducing resistance and  aiding in not only extra power but better fuel mileage. Helping to keep  weight in check a freshly designed cooling head features a 3mm lower  height and is 14g lighter overall lowering the engine's center of  gravity and shedding weight in a critical area.   Plus, these engines have been broken in by Adam himself using Adam's  "EBIS" engine break in services! Now, the same "Oil Bath" break in  service trusted by Ty Tessmann, Ryan Maifield, Robert Battle, Spencer  Rivkin, Mike Truhe, and many others is now available to you, performed  with the knowledge and precision that has made The Drake a legend in RC  racing.   Featuring a semi-long stroke configuration, this engine boasts a DLC  crankshaft with larger double tungsten counterweights and a unique  cylinder design that’s exclusive to the Drake edition engines. These  changes will provide smoother low end power and more overall torque than  the previous model. The AD3 is an excellent choice for both buggy and  truck racing as it provides a linear power band, exceptional fuel  mileage and tons of overall power.   Recommended Pipe and Header for the AD3 Engine:     Buggy: 2100SC pipe and 75mm manifold  Features:    Adam Drake’s unique engine specs not used on any other O.S. Speed engine Great for buggy and truck racing Updated cooling head; 3mm lower height for low gravity and 14g lighter. Black/blue double anodized head. Back plate with steel lining like B2104 for friction resistance Updated crankcase inner design for linear power transition from low–middle–high speed Redesigned cylinder liner with optimized porting DLC crankshaft with larger double tungsten counterweight Semi-long stroke configuration Blue anodized 6.5 and 7.0 mm carburetor reducers Ceramic rear bearing 21J carburetor O.S.SPEED P3 gold plug, great for medium and low speed torque performance, is also included Specifications:  Bore: 16.4mm / 0.646 in.  Cylinders: Single  Displacement: 3.49cc / 0.213 cu.in.  Engine (Only) Weight: 350g / 12.35oz  Power Type: Glow  Horsepower: 2.61 HP / 34,000 rpm  RPM Range: 4,000 - 42,000  Stroke: 16.55 mm / 0.652 in. output   Includes:     (1) AD3 Engine with Adam Drake Break-In (1) Engine to Header Gasket (1) P3 Gold plug (1) 21J carburetor Blue anodized 6.5 and 7.0 mm carburetor reducers