hey,

Keep in mind that your fuel tank should be in line with the carb. If you place the engine to high, you might have trouble with the fuel-feed.
I would keep as close to the trustline as possible. It isn't a pattern plane, so a little bit of difference shouldn't be a problem. But if you build this one right, it will keep you happy for many years.


Personnaly I think a .36 is too marginal.

I have flown my 4*60 with a OS .91 Fx (two-stroke) for years and always was happy with its performance. It may sound overpowered, but to me it felt like heaven, could do all kind of trics, on a calm day it even could Torque Roll, on a windy day it could do knife-edge.

If I would power the 4*40, I would go with a OS .46 Ax.

Just my opinion.

Phil