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Howdy all. After a long absence from the workshop, my son and I have restarted our efforts at building a corvair powered ch 750. With help from Doug at QSP in Cloverdale Ca. we got past a mental block(why is my elevator curved like this). Our now straight elevator is attached to the rest of the horizontal stabilizer,and I am ordering the rest of the airframe kit.
Having completed the crank case I would like to get input into cylinder and head options as well as firewall forward kits.
Looking forward to help from all
I've met and worked with William. Unfortunately , the requirements for my project have changed since then. We've decided to go with a 750 instead of a 601. The requirements for a 750 state 100 to 150 hp. The 2700 cc corvair puts out 90 to 100 hp. I think I might not like being on the bottom end of the horsepower curve. My questions are pertaining to how much HP do I need to not be underpowered. Also, are my 1964 heads convertible to the larger bore cylinders if I need to upgrade. If not are the cores exchangeable for the post 1965 heads...
Just my opinion, but if I was going with a Corvair, would do it 100% the WW way or no way. Why not take advantage of all the R&D he's done? The 2850 CC is rated 110 HP, but you probably already know that.
Regarding power needs for a 750, I've got a Cont. C-90 on mine & it flies great. It supposedly makes 90 hp @ 2470 RPM, & according to testing done by WW it doesn't even make that.
Thanks Jimmy. I am ordering the rest of the kit his week and am on the fence about the engine. I'd like to buy everything now( before my money disappears). Thanks for the input. Tim K
I'm really not up on the 2850 engine because The assembly manual didn't mention it. It was mentioned on the videos. One thing is for certain. Around northern California corvairs were not very popular. There are absolutely no core parts to be found. (checked all the junk yards) Looks like I'll be eating core charges if I don't stick with the standard displacement.
I have a 2700cc Corvair in my 601XL-B. It is a smooth running economical engine. I can offer that while the power is adequate at low density altitudes, at DA above 5000' the little engine doesn't offer much climb performance. I'm in Oregon and often contend with high density altitudes and high mountains where you want good climb performance safety margin up to 10,000' in summer convective conditions. I'd suggest going with as much displacement as you can afford.
I have been in touch with Woody down here in Vacaville Ca. He too urged me to go big as well.
He drives a 601 with a 2850 engine. He thinks my 1964 heads are amenable to boring out to fit the larger cylinders of a post 1965 engine and the big bore kit. I will have to contact the machinist on that. Since the 750 is a "dirtier" aircraft from an aerodynamic standpoint will that be enough to get altitude? I live in an area where you can go from sea level to 8000 feet in a couple hours. I imagine I'd want at least 10000 feet of service ceiling. I do recall while motorcycling through the backside of Yosemite that I wished my jets were a little leaner as well when my triumph started to lose power. I have no knowledge of aircraft carburetors though so I really don't understand the difference between mixture control and proper jetting.