O.S. Speed B21 AD3 Adam Drake 3 Competition .21 Nitro Engine w/Pipe Combo (Boost Bypass)

The O.S. Speed B21 AD3 Adam Drake 3 Competition .21 Nitro Engine with Pipe Combo has been developed in collaboration with international team driver Adam Drake to provide one of the best off-road engines on the market. Utilizing a boost bypass design, this engine provides smooth linear power making it easy to drive and put the power down. 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 than previous B21 engine designs. This combo includes a T2090 pipe and an M2000SC 75mm manifold.

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.

Features:

• Boost Bypass crankcase provides smooth linear power
• Rear cover plate with a built in thrust plate reduces friction and improves engine life
• Inner head uses an O-ring to reduce vibration and improve dust resistance.
• 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.
• 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:

Displacement: 3.49cc (0.213 Cubic Inch)

Bore: 16.4mm (0.646in)

Stroke: 16.55mm (0.652in)

Output: 2.65ps / 2.61hp @34,000 rpm

Practical RPM range: 4,000-42,000 rpm

Engine Weight: 350g (12.35oz)