I am building a 1/4 scale Sopwith Triplane with scale (under cambered) wing ribs. I will be fitting an OS 120 4 stroke to power it.

I am now ready to fix the fire wall.

My question is should I add any right and down thrust, the plans (Jerry Behrens) do not show any thrust, but having recently made a flair Taube and flair Pup both of these had significant thrust angles.