The Estes F15-4 Engine Bulk Pack gives hobby rocketeers reliable, high-performance power at a great value. This bulk pack contains everything you need to fuel eight launches - 8 F15-4 engines, 10 starters, and 8 starter plugs - making it ideal for group launches, club events, or anyone who likes to keep spare engines on hand for fast turnaround. These full-size 29 mm engines bring mid-power performance for larger model rockets while keeping handling and storage simple. Built for rocketeers who want dependable altitude and clean, repeatable performance, the F15-4 balances strong thrust with a predictable burn profile. The engine delivers a robust 49.61 N-sec of total impulse and a 4 second delay for comfortable recovery timing, so it launches heavier hobby rockets cleanly without sacrificing control. Whether you fly for fun, display, or competition, the F15-4’s consistent ignition and stable thrust make it a favorite when you need confidence on the pad. Key flight specs you’ll want to know - total impulse 49.61 N-sec, time delay 4 seconds, max lift weight 21.0 oz (595 g), max thrust 25.26 N, thrust duration ~3.45 seconds. Each engine measures 4.5 in (11.4 cm) long, 29 mm diameter, and weighs about 3.59 oz (101.8 g) with 2.12 oz (60.0 g) of propellant. Recovery wadding is not included, so be sure to add wadding and a properly sized parachute or streamer for safe recovery. These engines are designed for rockets that accept 29 mm motors and for flyers who follow established safety practices. Stock up, save, and spend more time launching. The F15-4 Engine Bulk Pack is ready when you are. Add this pack to your next cart to streamline prep for club launches, backyard sessions, or classroom demo days. Always follow the NAR model rocketry safety code, use appropriate recovery wadding and a certified launch controller, and launch only in approved open areas. ATTENTION: Estes Industries, LLC requires all purchasers and users of Estes® Model Rocket Engines to adhere strictly to all applicable local, state, and federal laws, regulations, and safety standards. The user assumes all responsibility for the safe and lawful use of Estes® products. Estes Industries, LLC expressly disclaims any and all liability for personal injury, property damage, or other loss resulting from the misuse, improper handling, or unauthorized application of its model rocket engines.
