RE: Biplane rolls violently left on takeoff
I have a similar size biplane with an OS 46. It is balanced a little more tail heavy than I prefer, but I manage OK since I hate to add any more weight to the nose. I believe because of this tail heavy condition it is a handfull to handle on takeoff. Wants to track left hard, and if lift off is early it will be a handfull till air speed builds up. If I have not flown it for a while I have to concentrate exceptinally hard on the first takeoff. Once in the air everything is fine. Very, very aecrobatic due to the slight tail heavy condition. Check you CG and settle for more nose heavy.