The Estes B4-2 is an 18 mm single-stage model rocket engine designed for lightweight rockets weighing up to 4.0 ounces or 113 grams. Its steady thrust and two-second delay make it well suited for models that need a dependable boost followed by a short coast period before recovery system deployment.
Each package includes three B4-2 engines, four starters, and four starter plugs, providing the essential ignition components needed for multiple launches with compatible model rocket equipment.
The B4-2 delivers a total impulse of 5.00 N-sec with a maximum thrust of 13.20 Newtons or 3.0 pounds. Its thrust duration is approximately 1.10 seconds, followed by a two-second delay before ejection. This combination provides predictable acceleration and recovery timing for compatible lightweight rockets.
Each engine measures approximately 2.8 inches or 7 centimeters long and has an 18 mm diameter. The engine weighs approximately 0.66 ounces or 18.7 grams and contains approximately 0.27 ounces or 7.6 grams of propellant.
The B4-2 is a practical choice for compatible model rockets used in classroom demonstrations, club launches, recreational flying, and other applications where consistent performance is important. Its balanced thrust profile makes it suitable for both beginning and experienced rocketeers. Always verify the rocket manufacturer's recommended engine configuration before use.
Purchasers and users of Estes model rocket engines are responsible for following all applicable local, state, and federal laws, regulations, and safety standards. Model rocket engines must be handled and used only as intended and in accordance with established model rocketry safety practices. Estes Industries, LLC disclaims liability for personal injury, property damage, or other loss resulting from misuse, improper handling, or unauthorized use of its model rocket engines.
