Bob's V8 in the picture was made out of steel pieces machined then welded together. The engine was mostly the challenger from Coles plans. The opposed 4 cylinder was built from solid aluminum from Matsons's Mastive plans. Unfortunately I didn't get a picture of Bob's 1/6 scale Kinner 5 cylinder radial. Right now, Bob is building Ron Colonna's Offenhauser engine, and after that he hopes to build the Forest Edwards 5 cylinder radial.