BMatthews

I think the key here is that the 074 makes enough power to fly a much larger model than you think of usually being associated with small engines. You also need to bear in mind that wing area and weight enter the picture. Normally a 30 oz model would be considered as way over the top for these sized engines but on a powered 2 meter glider an 074 would haul it around at sport model speeds other than in a climb.

I set up a 6 foot span glider with an Enya 09 in the nose one time and you would not believe the shenanigans it would do. Yet that was not an equation for what most folks would consider an aerobatic sport model.

So if you want a lazy slow flying model consider at least a 50 inch span lightly made model. And it's fair to say that if a lot of balsa sticks and open covered areas don't scare you then an Old Timer free flight'ish design converted to 3 channels will be good up to a 60 inch size.