I've been looking at this new UMS 125cc 5 cylinder radial. It measures a 265mm diameter and rated at 8 horsepower. I see the saito fg90 measures around 250mm. For those of you that have installed the saito radial, do you think there is any more room to fit this engine? I've been day dreaming. Another option is their 90cc 7 cylinder rated at 6hp and 230mm diameter which should fit without too much of an issue, but may be too small later down the road for another airplane.