Brief Description: New Corvair engine design and build
When I began flying my 601XL-B with the 2700cc Corvair, it became obvious it didn't have the power required for safe operation at higher density altitudes. The easy fix would be to add more power. I was acquainted with Brady McCormick who had the Magnificent Machine company a while back. He still had useful Corvair parts and he agreed to help me with a larger, more powerful, Corvair engine.
The stock 2700cc engine was a smooth running sweetheart and I intended to stick with the Corvair with some power enhancing additions. Brady had 92mm nikasil lined aluminum cylinders and forged pistons to fit, and a 3.25" stroke crank so that set the displacement at 3236cc. I researched cam grinds using computer engine modeling programs. I used both Engine Analyzer Pro, and Dynomation 5 Pro to help with design. I settled on available grinds from Oregon cam grinders. One profile for the intake and another for the exhaust. Oregon cam grinders referred to it as a real "stump puller". I'll use roller rockers to help reduce friction and side load on the valve stems with the higher lift, steeper opening rate, of the cam. I designed a header type exhaust using primaries 33" long, 3 into 1 merge collectors feeding into a megaphone with reverse megaphone tip. I built the exhaust and used it on the 2700cc first and it worked well. For the 3236cc I'll need to step the primary size up from 1.25" OD to 1.375" OD at about halfway down the primary length. Bigger merge collectors and megaphones too. Power doesn't come cheaply! I'll keep the same Rotec slide carb I had on the 2700cc as well as the dual Ford EDIS ignition systems since they both worked so well. The intake system will have individual 18" runners to each cylinder going to a common plenum fed by the Rotec. The ports will be enlarged and shape changed since the Corvair heads have such poorly designed ports for good flow. No need to use 140 heads because they have valves and ports too large for good power in the RPM range used for direct drive aircraft engines. (Continued)
