take out, but it is on par with the new Foras and maybe even a bit better.
All this rich running sounds a bit foreign to the usually recommended break in for ABC/ABN engines. Big bore ABC engines tend to wear out the conrod if run too rich during the first runs. The procedure for the .15s is to use a prop one size smaller than a flying prop and run near the expected fly- ing rpm but on the rich side of peak power. It might have something to do with new materials and the fact that a .15 has a rel- atively light piston and relatively lower bearing loads.
The fit has a lot to do with it too. All these engines were squeaky tight at top dead cen- ter when cold. As soon as they warmed up from a few backfires or a short run though, the prop would flip freely. I don’t have the tools to measure it, but it seems likely these smaller engines have less taper in the sleeve than the older, bigger mills. Once the Foras are broken in they flip over freely, but will still squeak tight at the top of the stroke if turned over slowly.
The Zalp seems to run “colder” than the Fora. Even after break-in, it is much fussier to start when the temperatures are below 65. The Fora will start and run happily down into the 40s. So take it easy with the break-in and enjoy flying the plane. The en- gine will get a bit smoother and faster with every flight. Once it settles down, it will be good for several hundred flights if kept clean and not run too lean.
Combat training redux Hitting the nail again, all the flying in the
Shawn Cook grabs his dad’s plane (above) to get him back up in the air. It worked. Nice, sturdy plane. Keith Marks, also a member of the HAMS club, built this nice Vernon Hunt designed Dominator (below) with a Veco. The popular vintage Combat plane has its own class in the UK. Keith hails from South Africa via the UK. A popular tactic in the day was to crash land to avoid a cut. With a diesel engine, a good pit man could usually get the plane back up with just a couple of prop flips.
world won’t do any good if you don’t analyze where you make mistakes and practice how to fix them. Even something as “simple” as flying eyes off your own plane has to be prac- ticed continually. I went to a couple contests in the spring and saw this mistake probably a hundred times—somebody doing a loop or eight right in front of themselves with their eyes glued to their plane.
Pick one of the tamer planes to work on this and try doing the stunt pattern clover- leaf. As the plane is flying level at 45 de- grees look ahead, pick a spot and start the maneuver there. Keep your eyes glued to the spot and keep track of the plane in your peripheral vision. Most folks can still see pretty clearly as far as 80 degrees or so left and right without moving their eyeballs, and the same up and down. Keep your eyes wide open and you can see even wider. Then try it from inverted flight.
Another way to visualize what is going on in a match is to use stick airplanes such as the ones the RC pattern flyers use. Draw a little plane outline on a thin sheet and glue the left wingtip to the end of a dowel. Get a friend to make one too and practice flying matches with him. It’s a good way to re-em- phasize which maneuver gets you into trou- ble without wasting a plane. Yes, it will make you both look silly as all get out, but it is a great way to learn.
FLYING MODELS 33
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