Hi

Need some advice. I want to take the plans for a Carl Goldberg Skylark 56, expand them
by 25% (wingspan to 70 inches) and use a pair of Wankels engines for power. The original
Skylark used a 40 size engine. Do you think the Wankels will be enough engine for that
wingspan?

Thanks

Ed

Ed,

As I recall the Wankels are considered 30 size engines so you would want the Skylark to be about 60” to 62” wing span like a typical 60 size aircraft.

An OS Wankel is .30ci but has the power of a .40-.45

According to the OS specs is a but stronger than a LA .46
http://www.osengines.com/engines/osmg1401.html

peak power is 1.27ps @ 17,000 rpm

Did they redesign the engine? it's listed as new on the OS site..

It's a spendy little engine.. Tower wants $450 for one.

actually the original skylark twin showed 15 size engines as a twin due to the nacelle size and tank space.

Two engines of the same displacement as a single engine will always offer more power due mainly to the additional prop disk area, or so I've been told. I've got no doubt that two Wankels would easily fly a 70" twin with power to spare.