We really do have a lot of engine Choices in the 24mm line. We could go with reducer and use C12 or D16, we could use Estes C11 or D12 or even E12 with added nose weight. We could go with Aerotech 18mm on reducer such as:
Single Use 18mm Motors

Time Motor Max Total Average
Motor Delay Diam. Liftoff Impulse Thrust
Product # Type (sec) in/mm Wt. (oz) lbs/N-s lbs
ARO42104 D21 4T 2.75/70 16.0 4.5/20.0 4.7
ARO42107 D21 7T 2.75/70 11.2 4.5/20.0 4.7
ARO52504 E25 4T 2.75/70 16.0 4.5/22.0 5.6
ARO52507 E25 7T 2.75/70 12.0 4.5/22.0 5.6
Single Use 24mm Motors

Time Motor Max Total Average
Motor Delay Diam. Liftoff Impulse Thrust
Product # Type (sec) in/mm Wt.(oz) lbs/N-s lbs
ARO51504 E15 4W 2.75/70 16.0 9.0/40.0 3.4
ARO51507 E15 7W 2.75/70 9.5 9.0/40.0 3.4
ARO53004 E30 4T 2.75/70 16.0 9.0/40.0 6.7
ARO53007 E30 7T 2.75/70 10.6 9.0/40.0 6.7

Or

Reloadable 18mm Motors

Time Motor Max Total Average
Motor Delay Diam. Liftoff Impulse Thrust
Product # Type (sec) in/mm Wt.(oz) lbs/N-s lbs
ARO41304 D13 4W .70/18 16.0 4.5/20 2.9
ARO41307 D13 7W .70/18 11.2 4.5/20 2.9
ARO41310 D13 10W .70/18 8.0 4.5/20 2.9
ARO42404 D24 4T .70/18 16.0 4.5/20 5.4
ARO42407 D24 7T .70/18 11.2 4.5/20 5.4
ARO42410 D24 10T .70/18 8.0 4.5/20 5.4
ARO52704 E27 4T .70/18 16.0 5.2/23 6.1
Reloadable 24mm Motors

Time Motor Max Total Average
Motor Delay Diam. Liftoff Impulse Thrust
Product # Type (sec) in/mm Wt.(oz) lbs/N-s lbs
ARO40904 D9 4W 2.75/70 7.1 4.5/20.0 2.0
ARO40907 D9 7W 2.75/70 4.2 4.5/2.0 2.0

ARO41504 D15 4T 2.75/70 16.0 4.5/20.0 3.4
ARO41507 D15 7T 2.75/70 11.2 4.5/20.0 3.4
ARO41510 D15 10T 2.75/70 8.0 4.5/20.0 3.4

ARO51103 E11 3J 2.75/70 16.0 7.9/35.0 2.5
ARO51105 E11 5J 2.75/70 12.0 7.9/35.0 2.5

ARO51804 E18 4W 2.75/70 16.0 9.0/40.0 4.0
ARO51807 E18 7W 2.75/70 9.5 9.0/40.0 4.0
ARO51810 E18 10W 2.75/70 5.5 9.0/40.0 4.0

ARO52804 E28 4T 2.75/70 16.0 9.0/40.0 6.3
ARO52807 E28 7T 2.75/70 10.6 9.0/40.0 6.3
ARO52810 E28 10T 2.75/70 7.1 9.0/40.0 6.3

ARO61203 F12 3J 2.75/70 18.0 9.7/43.0 2.7
ARO61205 F12 5J 2.75/70 15.0 9.7/43.0 2.7

ARO62404 F24 4W 2.75/70 16.0 11.2/50.0 5.4
ARO62407 F24 7W 2.75/70 9.5 11.2/50.0 5.4
ARO62410 F24 10W 2.75/70 5.5 11.2/50.0 5.4

ARO63906 F39 6T 2.75/70 18.0 11.2/50.0 8.8
ARO63909 F39 9T 2.75/70 14.0 11.2/50.0 8.8
ARO63912 F39 12T 2.75/70 9.0 11.2/50.0 8.8

Some of those are way to powerful for my liking where I fly now days, but they all are possibilities that is for sure.

I like the E11, love the slow flight with heavy black smoke but still to much motor for where I fly. I use to use that motor on light factory built 2001 Saturn V.