Your model airplane engine will be either a bushing or ball bearing
engine. By design, bushing engines are considered ECONOMY or LOW BUDGET engines. The most
common bushing engines would be the OS "FP" and "LA" series engines.
To set the record straight, when referring to bushing or ball bearing engines you are
speaking specifically of the crankshaft support and that is it.
The Economy bushing engines differ from the "upper class" ball bearing engines
in many more ways that just the crankshaft support! The bushing engine is fueled by an
air-bleed carb, whereas the bearing engine uses a two needle carb. The port timing is
radically different as well. Last but not least, the bushing engine generally doesn't have
a booster port like the bearing engine.
Bushinged engines are usually dependable, easy starting, and durable. But they lack the
go-power of a similar size bearing engine. And understandably so. Most beginners buy a
"trainer" type airplane and usually get an LA or FP grade engine for the
power-plant only to discover that the bushing engine will barely get the plane off the
ground. This usually leads to a second engine purchase, being a ball bearing engine of
some brand. You didn't gain anything by going with the bushing engine. In fact, it was a
pricy lesson to learn.
Don't get me wrong, bushing engines are OK in their own right. Just don't expect much
performance from them under normal circumstances. The hottest "trainer"
sized engine (being the 46) on the market today is the OS 46AX engine. This engine
will effortlessly power a trainer as well as ANY sport plane in its class with extreme
authority. SO, why would someone spend $59.95 for a piddling 1 horsepower bushing
engine when you can get a 46AX cranking out a massive 1.65 HP for $109.95?
My recommendation is, If you're just getting into the hobby buy premium products
regardless if it's an airplane, engine, or radio gear. It'll cost you less money in the
long-run, and your likelyhood of flying SUCCESS will improve greatly.
It is also worth mentioning that having the extra power will more than
likley get you out of trouble than having almost enough. Such as an aborted landing, the
extra power will allow you to gas it and pull up instead of stalling. You can always
throttle back when needed, but when you need the power and it 'taint there the ground will
rise up smite thee!