The Estes B6-4 is an 18 mm single-stage model rocket engine designed for rockets weighing up to 4.0 ounces or 113 grams. Its moderate thrust and four-second delay provide a balanced flight profile with a strong boost, a controlled coast period, and dependable recovery system deployment.
Each package includes three B6-4 engines, four starters, and four starter plugs, providing the essential ignition components needed for multiple launches with compatible model rocket equipment.
The B6-4 delivers a total impulse of 5.00 N-sec with a maximum thrust of 12.10 Newtons or 2.7 pounds. Its thrust duration is approximately 0.80 seconds, followed by a four-second delay before ejection. This combination makes it a versatile option for compatible lightweight and standard-size model rockets.
Each engine measures approximately 2.8 inches or 7 centimeters long and has an 18 mm diameter. The engine weighs approximately 0.63 ounces or 17.9 grams and contains approximately 0.23 ounces or 6.5 grams of propellant.
The B6-4 is a practical choice for beginner and intermediate rocketeers, educational launches, club events, STEM activities, and recreational flying. Its predictable performance makes it suitable for a wide range of compatible single-stage model rockets. 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.
