Model rocket engines are the heart of any launch, dictating altitude, stability, and the overall excitement of the flight. Selecting the correct engine ensures a safe and successful launch, maximizing the potential of your rocket and providing a rewarding experience for hobbyists of all levels.
- [Reliable C6-5 Performance] Each C6-5 engine delivers a total impulse of 10.0 Newton-seconds with a 5-second delay between thrust burnout and ejection charge activation, providing optimal altitude for parachute deployment on mid-power model rockets.
- [Convenient 3-Pack] Includes three individually sealed C6-5 rocket motors, giving you multiple launches per package — ideal for repeat flights, field testing, or stocking up for launch day events without needing to reorder frequently.
- [Wide Rocket Compatibility] Designed to fit standard 18mm motor mount tubes, these engines are compatible with a broad range of Estes and other model rockets engineered for C-class motors, including popular kits like the Alpha, Crossfire ISX, and more.
- [Trusted Brand Quality] Manufactured by Estes Cox Corporation, the industry leader in model rocketry since 1958, each engine undergoes rigorous quality control to ensure consistent thrust, reliable ignition, and safe ejection charge performance flight...
- [Safe and Easy to Use] Engines are designed for use with standard Estes igniters and launch controllers, requiring no special tools or modifications — simply insert, connect the igniter, and launch. Recommended for rocketeers ages 10 and up with adult...
- Combo pack includes 9 engines total — three A8-3, three B4-4, and three B6-4 engines. Starters and plugs are included. NOTE: Please verify that these engines are compatible with your model rocket before purchasing.
- All the engines you need for low and medium altitude model rocket flights!
- The A8-3 is a single stage engine designed for flights in rockets weighing less than 3 ounces, including the engine. It is ideal for first flights and small flying fields as you get used to how your rocket will perform and where it will land in your...
- The B4-4 engine is suitable for use in rockets weighing roughly between 1 and 2 ounces, which is typical of most rockets being 1 to 2 feet tall. It will almost double your altitude compared to the A8-3.
- The B6-4 is a medium impulse engine that delivers high altitude flights. It works great for launching larger, heavier rockets, too
- BEGINNER MODEL-ROCKET LAUNCH SET: The Tandem-X rocket-model launch set offers adults and kids ages 10+ hours of fun during the holidays as they complete and launch our Amazon and Crossfire ISX rocket models. This set includes the easy-to-assemble Amazon...
- 2 SOARING ALTITUDE HEIGHTS: Our Tandem X set offers a high-performing power duo with our giant 30-inch Amazon model (600-foot projected altitude with a C6-5 rocket engine) and our streamlined 15.6-inch Crossfire ISX model (1,150-foot projected altitude...
- READY TO ASSEMBLE: Our beginner model-rocket launch set comes with 2 build options. The precolored Amazon model features plastic fins and self-stick graphics and can be built in an hour. The Crossfire ISX model comes with laser-cut wood fins, self-stick...
- SAFETY FIRST, FUN ALWAYS: Our rockets and rocket launch accessories are designed to be used with the NAR (National Association of Rocketry) model-rocket safety code. Always ensure you have an appropriate launch site, stand back at least 15 ft., insert the...
- WE IGNITE IMAGINATIONS: Since 1958, Estes has created educational rocket kits and displays designed for an unforgettable aerospace experience. As a family-owned company, we have grown to offer exciting STEM products that engage aspiring rocketeers and the...
- BEGINNER MODEL ROCKET SET: The Estes Athena model rocket gives kids ages 10+ and beginners an easy way to experience real rocket launches with no building required! This ready-to-fly model rocket kit includes a fully prepared rocket with a parachute. This...
- SOARS UP TO 1,125 FT.: Our high-flying Athena rocket features a bright 12-inch parachute for safe recovery and soars up to a projected altitude of 1,125 ft. (343 m) with a C6-7 engine (sold separately). It is also compatible with the A8-3, B4-4, B6-4, and...
- READY TO FLY: Rocket-building kits are creative, educational gift ideas for Christmas or special-occasion surprises! This beginner-friendly Athena rocket comes fully assembled and just takes 15 minutes of preparation time. This model pairs with the Porta...
- SAFETY FIRST, FUN ALWAYS: Our rockets are designed to be used with the NAR (National Association of Rocketry) model-rocket safety code. Always ensure you have an appropriate launch site, stand back at least 15 ft., insert the safety key, issue a...
- ESTES EDUCATION: Since 1958, Estes has created educational rocket kits designed for an unforgettable launch experience. As a family-owned, US-based company, we offer exciting and engaging STEM products for all interests, skills, and power levels.
This article is part of our complete guide Sports & Outdoors — browse all our comparisons and buying guides.
Last update on 2026-07-18 / Affiliate links / Images from Amazon Product Advertising API
How to Choose the Best Model Rocket Engines
Understanding Engine Codes
Model rocket engines are classified using a letter-and-number code. The first letter indicates the total impulse (power), with each subsequent letter representing double the impulse of the previous one (A, B, C, etc.). The first number signifies the average thrust, and the second number indicates the delay time in seconds before the ejection charge deploys the parachute or streamer. For example, a B6-4 engine has a B total impulse, an average thrust of 6 Newtons, and a 4-second delay before ejection.
Choosing the Right Engine Size
The appropriate engine size depends on several factors, including the rocket's weight, size, and intended flight profile. Lighter, smaller rockets often perform well with lower-power engines like A or B, while heavier or larger models may require C or D engines for adequate lift-off thrust. Always consult your rocket kit's instructions, as they typically recommend specific engine types for optimal performance and safety.
Delay Time Considerations
The delay time between motor burnout and ejection charge firing is crucial for a successful recovery. A delay that is too short can cause the parachute to deploy while the rocket is still ascending rapidly, leading to instability or damage. Conversely, a delay that is too long might result in the parachute deploying too late, causing the rocket to fall from a high altitude. Match the delay time to the rocket's expected altitude and flight trajectory.
Safety and Handling
Model rocket engines are designed for single use and should be handled with care. Store them in a cool, dry place away from ignition sources. Always follow the manufacturer's safety guidelines and local regulations regarding their use. Ensure you have the proper igniters and launch equipment, and always launch in a safe, open area away from people, buildings, and dry vegetation.
Comparison Tips
- Weight vs. Power: Heavier rockets need more powerful engines to achieve liftoff.
- Altitude Goals: Higher flights may require longer delay times.
- Rocket Kit Recommendations: Prioritize the engine types specified by the rocket manufacturer.
- Launch Site Conditions: Consider the size of your launch area when choosing engine power.
