The Engine Shop - 2001/01
For More than 60 years, one particular size of model engine
has been almost an orphan, at least in competition classifications:
the .10 displacement engine.
When the Academy of Model Aeronautics (AMA) established
“classes” of model-engine sizes in the 1930s, it set the upper limit of
Class A at .199 cubic inches. That was purely an arbitrary decision—
a “best guess” on someone’s part as to what would be a good
dividing line to separate “little engines” from the “midsize” Class B
engines (.200 through .299).
At the time, that probably didn’t seem important. Most gas model
flying—all of it Free Flight (FF) then—was done with Class C
engines (.300 and upward). Few engines on the model market were
much less than .36 displacement.
The Engine Shop
THE FIRST internal-combustion engine used to power a model airplane in flight was British engineer David Stanger's 1906 four-stroke V-4—spark ignition, of course. Its 6.75-cubic-inch displacement is like that of some of today's Giant Scale power plants. However, it weighed 51/2 pounds, and its output of approximately 1 1/4 horsepower was surpassed years ago by competition two-stroke .15s (glow and diesel types).
The Engine Shop
THERE ARE THREE Joe Wagners who have become well-known in the model-airplane game. One is a top-level rubber-power competitor living in California; another is a New Englander, perhaps best known for his attempt some years ago to manufacture replicas of the post-WW II Bantam .19 and Morton M-5 spark ignition engines. But I'm the Joe Wagner who was Chief Engineer for Veco in the 1950s; organized the Model Engine Collectors' Association (MECA) around 1960; and wrote Model Airplane News' engine column for almost ten years. Now I'm here at Model Aviation to do what I can to help you. This new column is about all kinds of model airplane engines (except Electric motors, rocket power, gas turbines, and pulse jets). We'll talk here about glow, spark ignition, and diesels; modern engines and old-timers; two-strokes and four-strokes; Free Flight engines, Control Line engines, and RC power plants; even CO2 and compressed-air motors. That's a lot of interesting territory to cover!
The Easy Way: Out of Trees
ALTHOUGH FREE FLIGHT flying is fantastic fun, a few aspects of the activity are not. Scrambling up a pine tree after an errant Towline Glider, or helplessly glaring at your Indoor model trapped in the rafters of a gym is no one's idea of a great time. There are better ways to demonstrate the joys of Free Flight to other modeling clans. To minimize my own discomfort and frustration in those situations, I recently designed and built myself a model airplane retriever: a long-reach contraption that extends upward many feet to easily dislodge my models from captivity in trees or gym roof trusses.
The Engine Shop
MY FIRST MODEL AVIATION column isn't out yet, so no reader response has come in, but I have ample engine topics for my second column anyway. Some model engine columns feature detailed analysis and performance tests of new power plants, or troubleshooting for older power plants - I don't plan to use much of either. For one, I've seldom met a model flier who cared greatly about technical trivia, such as whether his engine's piston was made from sintered iron or Meehanite. And although performance tests are all right in their own way, engines from the same production batch can vary widely in behavior and output.
