4-second delay enables reliable recovery system deployment at peak altitude
Compatible with a wide range of Estes rocket kits for versatile use
Each pack includes three engines, four starters, and four plugs for multiple launches
Extra starter per pack provides added convenience and backup
Summarized by Shop
The Estes B4-4 Rocket Engines are ideal for mid-powered model rockets that demand a steady climb and reliable deployment. These single-stage, 18 mm engines offer a balanced performance with moderate thrust, making them a great choice for both new hobbyists and seasoned flyers looking for consistent flight results. The B4-4 is specifically
Engine Type
Single-stage 18 mm
Thrust Duration
4 seconds
Recommended Rocket Weight
Less than 3.5 ounces (including engine)
Material
Cardboard, Plastic, Clay
Color
Beige, Green
Battery Size
None specified
Summarized by Shop
4.8
21 ratings
5
4
3
2
1
I was overjoyed to reconnect with Estes once again. It was one of the most enjoyable hobbies of my youth in the 1970’s! Now I’m doing it with my grandkids. These are great quality hobby rocket engines
D
David · August 5, 2026
Excellent as usual
D
Deborah · 9 days ago
I love your product's I have been flying Estes rocket's since I was a kid.
