Get your larger model rockets in the air with these popular rocket engines.

• Engines come with igniters, plugs, and instructions
• Compatible with big daddy, green eggs, etc.

Model rocket engines use letters and numbers to describe their impulse, thrust, and ejection variables. The letter represents the total impulse, and each letter is double the one before it. 'A' engines deliver 2.5 N·s of impulse, while 'B' engines deliver 5.0 N·s, etc. The first number is the average thrust, and the second number is the time delay between powered flight and the ejection charge.

Thus, a C11-3 engine delivers a total impulse of 10.0 N·s, with an average thrust of 11 N. The total time of powered flight is less than 1 second. During the 3 second delay time, the rocket is a projectile traveling toward apogee. After the delay, the ejection charge engages the recovery system. In general, the higher the average thrust, the greater the acceleration of the rocket. Heavier rockets generally need more thrust.

Estes large rocket engine packs come with igniters, plugs to hold the igniter in place, and instructions for new rocketeers. Bulk packs also include recovery wadding. Be sure to reference the Engine Chart and Impulse Graphs for detailed information about thrust, maximum lift weight, and duration.