Engine Sizing and Selection

Dillon Pyron wrote in message
A twin powered by two unreliable engines is just an underpowered
single waiting to happen.

And when that happens, you land and get it fixed. But in the mean
time you have an aircraft well powered by a pair of engines with power
to weight ratios difficult to match at a cost within the reach of the
working man, with a composite reliability that exceeds a single 4
stroke.

It's true that the lone 2 stroke engine is typically paired with
aircraft that land off field as matter of course (golf) or can put
down pretty much anywhere when there is a failure (powered parachute).
But there are applications where weight is of paramount importance
(Hey, isn't that every airplane?) like ultralights. So thats the idea
of the dual system. and of course less engine weight means, less
airframe structure required to support it, less power required to
lift, and less wing to support all that, and less fuel to push all
that, etc...

BTW, Isn't that RV-4 with the 13B in it sweet looking?
http://powersportaviation.com/images.../Airplane2.jpg
Getting rid of those cheeks really cleans things up. The RV-6 doesn't
seem like such a great fit since Vans already made the frontal area
large in anticipation of the opposed cylinder engine.