Thanks Guys for all your previous respones .
I have a question about the engine's installation angle.
i have install my engine on the new funtanas 40 on it's side as the manual says but while picking the fuselage up gently to turn it around i found a very noticeable tendency to roll over to the heavy side.

doesn't installing the engine that way causes a bad lateral balance ?
won't it be better to install it upside down especially on those 3d models which flies slower and requires an exact later balance ?

Hi, If you keep it on its side, as you have already stated, you must balance it laterally. If you would like to mount it inverted, thats no big deal, its your choice. Still check the lateral whichever way you choose. Joe

I dont recall the engine you are using. But on my funtana with a SAITO 100 which is probably about the heaviest engine that you would want to put on there it only took a half ounce of weight (two little blocks) on the right wingtip, with the engine mounted sideways. If you are using a four stroke engine and you dont want to add that little bit of weight, then you can mount it upside down, which also looks better in my opinion. It veers away from that uneven look. If you are however using a two stroke, you will probably be better off mounting it as illustrated in the manual. In my experiences, two strokes tend to load up very easily when mounted inverted. Plus most any two stroke that would be used on the plane would be short and therefore the weight of the engine or muffler wouldnt have as much leverage as one with a taller head height. good luck.

Some two strokes have inverted starting probs but my Irvine .46 and .53 start first flick inverted.

If you have inverted starting probs try turning the plane over by putting it on a stand or getting a friend to help out.

The Engine is saito 72 and i really prefer to install it on it's side unless it's causing a later balance issue

I always balance mine laterally but you probably won't notice the difference if
you choose not to. The weight of a side mounted engine makes little difference
in the flying. If one wing tip is heavier than the other you definitely will notice it.

tommy s

A small imbalence of say 10g is negligible, but pull a 6g loop and that 10 g becomes 60g which will cause some problems and may cause the aircraft to screw out of the loop.

I read that in RCM&E

If you are mounting it sideways i will not cause a problem. I would put about 1 1/2 or 1 3/4 peices of lead (about 3/8 or 7/16 of an ounce) on the right wingtip and it will be perfect. Plus you can cut about a 3x3" piece of white covering and tack and shrink it over the weight. That will definately secure it plus it covers up those ugly grey weights.