I did help a friend 2 years ago to put together the Abbra with the ZDZ 40 (non F3A). The plane was a little over 11 lbs. I am sure that could be below 11lbs by re-working some areas or just using the f3a version. Just replacing the 3 blade prop with wood prop will do it. We flew it first without soft mount and flutter in one aileron almost destroy the plane. After that we installed a soft mount and worked great. I think the noise level was comparable with the glow engines. We were using the gas carbon pipe. Check the attached pictures. Unfortunetely, my friend stop flying and sold the plane. I flew it few times and I feel that power was a little less that you get flying glow (Master Schedule). However, we didn't try different props and I think the 3 blade prop was too much load. I think the 26cc will work only for lower classes. It is a shame that we didn't have chance to fly it more.