I have to stick my nose in here and say a few things. Brian, I respect your viewpoint but I must disagree. Both hit n miss engines and make n break engines are exactly the same type of engine. They both have the same parts and do the same thing. They are not different at all. They use different ways to control speed. Thats all. Make n break uses the ignition system and hit n miss uses aspiration.
The whole idea with hit n miss engines was that while the exhaust valve was kept open, the engine would breathe fresh air while not making compression. They would freewheel several strokes. This helped greatly in keeping the engine cool. Power demands were not critical and huge flywheels kept irrigation pumps turning no problem. (example) They would run for weeks at at time as long as you kept fueling and oiling.
Make n break engines were usually used where more constant power was demanded, such as boats where turning a prop was very constant. Or perhaps in a shop, powering equipment. (example) Early gas tractors used both types to provide the power needed. Much smaller flywheels were needed as the power strokes were more often.
Before I posted my engine video which I mistakenly called a make n break, I ran the engine with the flyweights wired down. I ran the engine with no speed control at all. The carb has no throttle, the engine ran free. I knew that I could control speed with the “off” switch. Yet, it ran quite nicely at about 2000 rpm constant. (guess) What would that engine be called? Can’t call it a make n break…. can’t call it a hit n miss….. it’s the same engine… but what is it? Now, it’s called a hit n miss because I cut the wire holding down the flyweights.
WW1 aircraft used an ignition cutoff system to control the speed on their rotary engines. It’s the same stuff…. control speed. (just an example)
So, thats my point. It’s all the same. They’re not different types of engines… they’re just used differently and adjusted or modified to perform the task needed. The exhaust sound is a result of the application, and the positioning and size of the pipe, and the amount of air exiting. Thats why old open engines, tractors, boats and such used a pipe sticking straight up with a rain flapper cap. Exhaust sound means nothing, Unless you’re parked next to my GTO.