Patriot (semi) clone build engine mount question

Hey guys. I'm preparing to re-live my time as a teen-aged rocket builder by building some of my old favorites. I'm planning to start with the old Estes Citation Patriot.

I've procured a Screamin' Mimi kit for the body tube and nose cone, but I also want to use a 24mm engine mount rather than the original 18mm. I have no doubt that the modded build will fly just fine with 24mm engines, but I would like to still have the option of using 18mm with an adapter.

I noticed in the original Patriot plans, as well as other 18mm Estes kits with a BT-60 tubes (Big Bertha, Der Big Red Max), a longer (>6") engine tube is used. My concern is that if I use the 24mm engine mount from the Mimi with an 18mm engine, there might not be enough pressure to pop the 'chute.

Anyone have any opinions on this?

Thanks in advance!

IIRC my first Bertha had a 70mm motor tube. This was early '60s. Never had an ejection problem. All my later BBs have had longer tubes with centering rings at each end. They are called 'stuffer tubes'. Yes, they are there to reduce the volume of the airframe tube.
For the Patriot, I would use ~170-180mm motor tube, the front centering ring seated against the aft coupler.
Happy flying!

Thanks, Mike. That's as I suspected. To be on the safe side, I'll definitely use a longer motor tube.

Since this project will serve to revive many long-dormant skills or learning new ones (printing my own decals), I'd hate to have it turn into a lawn dart.

I've launched a number of 18" BT-60 based rockets on 18mm and 24mm motors about 20 years ago. I suspect that when the Citation Patriot was originally released, there was a smaller ejection charge which made it necessary for the stuffer tube to reduce the volume. All the modern BT-60 based designs I've looked at don't have a stuffer tube. I'd say you're probably fine without one.

BTW, I've also got a clone of the Citation Patriot that I've built as a two stage payload version (I've still got to the decals though).

Great Rocket.