Im currently working on a plane. Span is 1050mm (around 40 inches) and the length is 850mm (around 33.5 inches) and i was wondering if anyone could help me with engine sizing (im not after exact answers; but just a guideline ir what you would use in a similar sized plane).

I was thinking a .25 2 stroke (as a complete guess) - any one else have any other suggestions?

...and im also unsure of going either electric or nitro, most likley ill choose nitro but in electrics case i was thinking of a brushed 400 cobalt motor or similar brushless (or as a last resort; a 480 brushed ferrite)...

to demystify this broad question ( sorry) im after a plane that is fairly if not moderatley aerobatic so i guess a OS .25 is looking good [&:]

Any input or comments are appreciated...

Hi DIYMark, Can you tell us a little more about the plane? Is it a high wing, low wing, what will it look like and what will it be made out of?

Your initial guesses are fairly good I think if it's a light plane. If it's a heavy warbird style plane you may need more power.

um its a high wing but the fuse is a box basically i think its similar to a plane called a ultra stick? ive seen it in ads in the elec. flight area and the plane is made of balsa and when im done with it it'll be fairly light, also it has a semi symetrical airfoil so theres a good amount of lift...

For most planes of that size a .25 would be way oversized. Depending on weight the correct size could be as small as a .049 or as large as a .20, even a .25 if it is a heavier plane built for ultra high speed.

This one is low wing but it's about the same size:

http://www.electrifly.com/speed400/gpma1156.html

so a 220w cobalt motor will do i think?

second thoughts, id rather have ic for this plane (as a new experiance - im used to elec) and id like one around .15 size... does any one know of other brands (beside) os that have good .15 size engnes?