wow! 30-60 class? I know of many instances where I would go with smaller engines than a da 50, I will give you DA may be the most powerfull 50, I dont know for sure but I do know that if that much power isnt necassary there are many other options than can result in less overall weight while still having 3d power. Back before the days of DA, 3W engines were the rage, guess what, they arent the lightest engines either. Just powerful cc for cc when compared to many other brands, same as DA. I guess I will have to dig my book out with the all up mounting weights for many of the popular glow motors being discussed along with my brison 2.4. I sent a moki 1.8 back to cheif aircraft because that thing was going to weigh just as much as my brison mounted up when I was looking for an engine for my 25%cap.