Re: my "off time" project
This engine, if it even runs when I'm finished, is for an all composite Formula One airplane known as a Kelly.
The Unlimited Scale Racing Association (USRA) is the sanctioning body for this stuff. The #69 plane IS NOT mine. It's a stock photo I pulled off the web just to show one assembled. These are 42% of scale models.
In the Formula One class your required to use an "untouched" 80cc engine made by Zenoah. Pump gasoline and a spec prop are required. I'm hoping to run in the Formula One Pro class which only has an 80cc displacment restriction. You can run any fuel/any prop.
This engine of mine will be running between 30-60 percent nitromethane/methanol for fuel.
Ignition systems are ditched in favor of glow plugs. Simpler and more reliable.
Speeds vary with class. The Formula One planes run around 130mph. The F1 Pro are close to 200mph. The Unlimited class hovers around 240mph and the experimental aircraft run closer to 260+.
http://usraracing.net/ I have a friend down in Flagstaff who's pretty much the smartest guy on the planet when it comes to this stuff. He's helped me ALOT with this project. He has a new engine for the Unlimited class that should put his plane over 300mph. These are actual speeds, not scale.
The aircraft typically use a one piece wing made from a honeycomb/composite material and they see G loads in excess of 40+ when cornering.
12 is generally lethal for a human being.
The track is two pylons spaced 1600 feet apart. Go fast turn left for six laps. If you do it right your plane shouldn't be in the air more than 2 minutes.
Seems contradictory, the faster you go the less time you get to actually do it. Maybe that's why I love drag racing too.
I'm hoping to gin up either a mechanical or maybe even an electronic fuel injection setup for this bugger. Three injectors. One in each transfer port and one in the crankcase to ensure the bottom end sees oil. (two strokes are lubricated by oil mixed with the fuel)
We'll see. I have the crank/rods done already. I'm frankensteining pistons from a different engine, although I did contact JE race pistons and they sent me unmachined forged slugs in case I want to do my own.
debating on the material for the liners. I have a stick of Durabar centrifugally spun, graphite impregnated, normalized, micro grain cast iron that I may use for liners. I can also just buy a finished liner from the same company I got the pistons finished pistons from. I may go that route because it'll be a drop in fit that way. Far less work.
Fun stuff!