Devil in the sky.. Heuva ( sorry abouf the spelling) A few things with the Spitty. No need to put in an electric fan for more cooling if you duct the air over your engine, thru the firewall, via a duct in the fuse and discharge the air out the bottom of the fuse where the oil cooler extends from the leading edge of the wing. You get plenty of cooling this way. You might reconsider the mechanical retracts for pneumatic ones. If you are designing them yourself you can still buy the small air cylinders and make them pneumatic. The gear with aluminum wheels and the long legs require quite a bit of effort to raise. Be sure to reinforce your gear blocks. The YA Spit has a weakness there. I boxed mine in on the sides and bottom adding more contact surface area to the foam. Regards BobH.