Hi Fellow RV4 owners,

I was in the same situation of which engine to put in my RV4. I ended up installing the OS .50SX. Like fun4me2fly, I also installed the flap option. It's nice to have the option of using or not using the flaps. It's good practice. The .50SX works great and it takes up the same space as the .40 and .46 engines. I don't have any four strokes yet but it is just a matter of time before I start using them. I really like the sound of a four stroker.
As far as the wing saddle you asked BCJETJOCK what he used, I'm a little old fashion on this. I still use silicone. I just put a good bead down on both sides of the fuselage, lay a piece of saran wrap over them, mount the wing and let it sit all night. In a day or so you take the wing off and trim the excess silicone off and you have a perfect match.
Keep up the good work and let us know how it flys.

Wayne