Radial engine blowers

[Bentwings]

Hi I’m about to start on an 18 cylinder ageless radial. I have a full cad system available, just walk in the door and have at it. I friend closed off his cad from the shop.
So looking at various models few have anything like a supercharger. I had a set of drawings years ago lost in a tornado. These were for an 18 cyl radial unknown designer. It did have a mini blower. I thought this was a good idea as I come from supercharged nitro burning hot rods. Miniatures like this probably won’t produce boost but the main thing is to provide air flow through a relatively restricted passage. You simple can’t spin the rotor fast enough to make boost. The drive becomes more complex as you increase the ratio. Beyond about 6to 1 gets tricky. Bearings and lubrication quickly becom an issue as well as impeller. I probably could do some analysis but it would be time consuming. If someone had a CBC capability one could make a series of them for testing. They can be 3D printed in plastic and more expensively in metal. My thought is to drive it with an electric motor getting really fancy one could make it adjustable by throttle linkage. Not real accurate but it’s not flying just bench running. I have some sketches of a bench top synonym also. There are a number of these on YouTube. Basically a pivoting mount and a scale. Props get scary in larger multi bladed even Rc model plane ones.so I’ll stay away from them..

so I’m just throwing this out here for some thoughts.

 

[Master]

Flew 25 years as a crewman (not pilot) in radials. The R-2800 had blowers, but the R-3350 had something called PRT's. Power Recovery Turbines. As a radio operator, my on ground maintenance was assisting the engineers. Lots of engine changes in 25 years. Unlike the Air Force, in the Navy, "you fly it, you break it, you fix it." Loved climbing out, suddenly dropping momentarily as the engineers shifted blowers. Loved "round" motors.

 

[Bentwings]

Flew 25 years as a crewman (not pilot) in radials. The R-2800 had blowers, but the R-3350 had something called PRT's. Power Recovery Turbines. As a radio operator, my on ground maintenance was assisting the engineers. Lots of engine changes in 25 years. Unlike the Air Force, in the Navy, "you fly it, you break it, you fix it." Loved climbing out, suddenly dropping momentarily as the engineers shifted blowers. Loved "round" motors.

I’ve read about this too. My father in law spoke about the blower changes in the Corsair he flew. He said it was a pretty good belt when it changed under power. I can imagine the mech cussing when one came in broken with burned pistons or bullet holes in them. I’m sure there was a quick fix in the islands. “ it was still running when you came in, it will run on the way out” LOL