cfellows said:
Don't want to hijack Dave's thread here, but for those of you who have built model airplane glow plug engines and stationary engines, what are the differences in skills required? It's my sense that stationary engines are more forgiving of less than perfect tolerances, but I also realize that 2-stroke glow plug engines are simpler in terms of number of parts.
What say ye?
Chuck
Chuck, I think it depends upon what your goals are. For a typical stationary engine, people generally like a "busy" appearance with lots of moving parts, governors, etc, and this adds to the color and character of the engine; and the goal for running is generally easy starting and smooth, consistent operation. Wringing the last Joule out of it is often secondary, or ignored entirely.
Guys that build one-cylinder glow aero engines are often looking for real performance, and spend more time ensuring the build is strong, light, capable of high revs under load. All this generally requires a bit more attention to tolerances, cam profile, materials, etc. Ultimately, while typical stationary engines usually have
many more parts, they are often a bit more forgiving in the end. Just a bit of generalization there.
Really, the only differences between steam and IC from our perspective is the tolerances needed for bore, piston, valves, and maybe the carburetor. These have to be approached with a different accuracy mindset. A steam engine will run with a reamed bore and a bit of a sloppy fit with the piston, and the valves don't need to seal as well, whereas an IC engine generally requires honing/lapping, correctly made rings, and valves that seal properly. But none of that is out of reach of anybody with a steam engine or two under their belt.
The good news with an IC engine... if you can get decent compression, you are 7/8ths of the way to success. Like just about every Dad has taught his son, if you have compression, fuel, air, and ignition, she'll run. Each of these is approached (and fine-tuned) separately.
