Engine Terminology as it Relates to Diameter/Length F Composite Sizes??

Ok, dumb question, but here goes:

I've got an Estes Nike Smoke that I have flown using an F26-6FJ 29/40 engine.

But I want a little more power and want to use an F32-4T 24/95 engine.

So, my question is: Those last numbers (29/40 and 24/95) are they size measurments for diameter and length?

If that's the case, I guess the F32 won't fit my Nike Smoke, right?? Or have I got it wrong with these numbers?? Thanks for any enlightenment.

Are you getting these numbers from Hobbylinc? If so they're confusing, if not useless. /40 sounds like a total impulse, and /95 sounds like a length in mm. The first number is diameter.

At any rate, the F32 is a 24mm diameter motor and will fit in your rocket but require an adapter.

I suggest you look on thrustcurve.com to understand what motors will fit your rocket.

The F26 has lower average thrust but more total impulse than the F32.

Yes, from Hobbylink. I'm interested in the 4 second delay and I think I can trade higher thrust versus lower total impulse. Just want it to fit!!

I don’t know what that 40 is doing in the F26. That motor is 98 mm long, easy to look up.

The second motor is indeed 24mm diameter x 95mm long.

reasonably sure that the engine case size is being mixed in and confuzzeling everything, engine case size is likely '29/40-120' so any reload for that case will fit the rocket, (the F52-6 worked nicely in my Nike).

Rex R said:

reasonably sure that the engine case size is being mixed in and confuzzeling everything, engine case size is likely '29/40-120' so any reload for that case will fit the rocket, (the F52-6 worked nicely in my Nike).

Click to expand...

That was my first suspicion, except the F26 is a single-use motor, and I can't find anywhere it is listed with a /40 at the end, including the packaging for the motor (at least, based on retailer image).

In any case, it appears to be a mistake. /40 has nothing whatsoever to do with that motor.

I assume because the post is in mid power and your saying 29mm - this is a PSII Nike Smoke ?
If so and you have a field large enough , why not a G40 ?? A chute release is your friend.
Mine flew very well on that- the F Motors just didnt seem enough to me.

neil_w said:

the F26 is a single-use motor, and I can't find anywhere it is listed with a /40 at the end...

Click to expand...

As I already said, this is an error/confusion on the Hobbylinc website. https://www.hobbylinc.com/aerotech-f26-6fj-single-use-motor-29:40-1-f-model-rocket-engine-62606

Depending on the available launch site, the PSII Nike-Smoke flies fine on F and G motors and if you left out the motor block, on larger motors like the AT H128. For 24mm motors you will need an adapter.

Ah, sorry, misread that above.