VairHeads, For those planning on using a Corvair engine, the very first step is to buy William Wynne's Corvair Conversion Manual, available from http://www.flycorvair.com/products.html, at the top of the price list. It details exactly which engines are preferable, as well as the rest of the process you'll need convert a Corvair for aircraft use. In the meantime, your best bet is any 1965 through 1968 95 hp or 110 hp engine. 1964's are usable, but are not as preferable due to oddball cylinders and correspondingly oddball cylinder and head spigots (although both of mine are 1964). Any engine earlier than 1964 will have a short stroke crank, and are definitely not preferable.
Although the higher horsepower turbos and the 140 hp sound more appealing, they are not what you want for aircraft use. The turbos have the wrong combustion chamber shape, and the 140 has huge valves that are more prone to dropping seats than the 95 or 110 hp engines, and don't perform as well at our low RPMs. There are a few of the 95-110 engines that have open chamber "smog" heads, and these are a big no-no due to lack of detonation resistance. Many of the 1969 heads are the smog type, so keep that in mind. The engine case serial numbers you'd want start with RA, RD, RE, RF, RG, RH, RX, RJ, RK for 64-68 95-110 non-smog engines, which should have head numbers 3856743, 3856759, 3878561, 3878562, 3878566, 3878569, 3883858, 3883863, or 3886259. All of these heads are 95 or 110 hp heads, and either will work fine. Cam and timing are a large part of the hp difference between 95 and 110 heads, so there's no real advantage to a 110 head over a 95 head. This list does not include 1964 engines, which also work fine but require the "1964-only" pistons and cylinders, which are still available but that may change, or cylinder spigots and heads can be bored to accept larger diameter later cylinders. Those case serial numbers are YC, YN, V, YL, YM, Z, ZH, ZF, W, ZD, ZG. Again, 95 and 110 hp engines is what you are interested in...but ANY 1965-1969 will have the right crankshaft and case, and if the price is right, you might as well pick it up and use it for spare parts (crank, case, pushrod tubes, oil housing, valve covers, etc). Going price for a good usable core is $100 to $300, but that's an insignificant part of the overall cost of your aircraft, so paying a little more for a known-good running Corvair is not a bad thing. My first engine was a complete basket case, which made reassembly a little more challenging. For more info on my Corvair engines (I have both a 2700cc and a 3100cc engine), see some of my Corvair stuff in the links at the top of http://www.n56ml.com/corvair/ . But as I said, if you are serious about going with a Corvair, buy William's conversion manual. He also sells all other parts you'd need to make the conversion. Also, there's a "Corvair College" on the weekend of June 3, 4, and 5, in Hillsdale Michigan. More details are at in the text near the bottom of http://www.flycorvair.com/hangar.html. Joe Horton, Mark Jones, and I plan to fly in there for the occasion. And there's an email list devoted to Corvair engines in aircraft, which I also run. To join it, send an email to corvaircraft-j...@mylist.net . There's a huge amount of info in the CorvAircraft list archives, which is at http://www.maddyhome.com/corvairsrch/index.jsp . Mark Langford ML at N56ML.com website at http://www.N56ML.com --------------------------------------------------------
