RE: What would a gas engine be compared to a glow
I'd revise that down a bit... though some gasser engines are more powerful for a given size than others.
1.80 4-stoke glow =~ 30cc gas
1.20 4-stoke glow =~ 26cc gas
.91-1.00 4 stroke =~ 20cc gas
35cc 2-st glow ( e.g. BGX-1 OS engine ) =~ 50cc