4-second delay for controlled parachute recovery enables safe landings on soft surfaces
Balanced thrust and altitude profile supports a wide range of model rocket kits
Consistent performance across multiple launches for reliable results
Includes starter and plug for easy installation in compatible Estes rockets
Pack of three engines provides multiple launches per pack
Summarized by Shop
The B6-4 is a widely trusted and well-balanced engine that offers reliable performance across a variety of model rocket kits. With a moderate level of thrust and a 4-second delay, it allows rockets to coast effectively before activating the recovery system, making it ideal for rockets that benefit from a longer delay phase after burnout.
Total Impulse
5.00 N·s
Time Delay
4 seconds
Maximum Lift Weight
4.0 oz (113 g)
Maximum Thrust
12.10 N (2.7 lbs)
Thrust Duration
0.80 seconds
Engine Length
2.8 in (7 cm)
Diameter
18 mm
Weight
0.63 oz (17.9 g)
Propellant Weight
0.23 oz (6.5 g)
Summarized by Shop
4.9
35 ratings
5
4
3
2
1
You can count on Estes engines for a super reliable flight. Fast delivery too.
R
Robert · July 15, 2026
Nice
J
John · August 8, 2026
These are great, I use these when a c6-5 will send a rocket way past 500 feet
