It seems most missed what I was talking about:

IN aerobatic aircrafts...a 26cc GLOW ( call it that because most understand that term and can Identify with it. One could call it a Methanol or nitro methane engine)
in this case a O.S. 1.60 fx (yes it is a 26cc engine) would be comparable to a 45cc or 50cc gas engine...

http://www3.towerhobbies.com/cgi-bin...?&I=LXKJB5&P=0
http://www3.towerhobbies.com/cgi-bin...?&I=LXTAW7&P=0
http://www3.towerhobbies.com/cgi-bin...?&I=LXLGM4&P=0

These are considered 1.60 sized GLOW aircrafts...
If you used a 1.60 glow (26cc) but changed to gasoline, you would use a 43cc Gasoline engine...

Engine: 1.6 - 1.8 cu in (26 - 29cc) 2-stroke glow engine OR
1.8 - 2.1 cu in (26 - 34cc) 4-stroke glow engine OR
1.9 - 2.6 cu in (32 - 43cc) gasoline engine (vertical mount)

In one review, a 1.60fx engine was used in the Topflite giant staggerwing, and flew well...
another used a 1.60 twin 4-stroke... .

The 1.60fx was also used in Gian aeromaster biplane and flew very well..
In the latter example, the Aeromaster was designed as a 50-60cc gasoline plane...

I hope I explained what I meant by "The stagerwing is a 1.60 sized glow plane, and a 50cc sized gasoline plane"

With a weight of 17-20 pounds and 1500 squars of W.A. ...It most def. is a 50cc gasoline biplane
or err um a 1.60 size glow plane...