2,775 cc Pistons are here.


Two very large corrugated shipping crates showed up from California today, inside are the first round of our new 2,775 cc piston kits. You can read more of the story here at this link: 2,775 cc Piston and Cylinder kits


These are the slightly smaller brother to our 2,850 cc kits. I specifically developed these to use standard +.060″ Hastings chrome Corvair rings (2,850 and 3,000 cc Corvairs use metric rings because their bore sizes are actually 90 and 92 mm respectively) and to be set up for floating wrist pins, unlike stock Corvair wrist pins which are non-floating. Of course they are forged and made in America.


The slight dish in the piston tops is designed to allow these pistons to be used with fuel as low as 87 octane when combined with 95 series heads. They are designed for 90-92 fuel with 110 series heads.  These engines will also run fine on 100LL fuel, but it will not be required.


The cylinders for these engines will be re-bored stock GM cylinders. I have long proven motors in this bore size to be completely reliable on stock cylinders. A side benefit is that these motors will be several pounds lighter than 2,850 engines which use the proprietary Clark’s Corvair full fin, thick wall replacement cylinders.


As per the linked story above, I don’t yet have the final pricing on these kits, nor do I have them on the products page. I will take care of this in the next week, as we asked before, if you are interested, just send me an email with “2,775” in the subject line, we will directly send the information on connecting rod options and pricing shortly.





Above, a 2005 shot of our personal Zenith 601XL in flight on it’s way home from Oshkosh. During the years we owned and flew the aircraft, it used two different engines. The latter was a high compression 3100 cc engine with 140 series heads, but it did it’s first two flying seasons and dozens of demo flights on it’s original 2,775 cc engine. While many new builders would guess that there would be a tremendous performance difference, there was a fair difference in climb rate, but the 2,775 cc motor was a solid performer that we tested to prove that it still had a positive climb rate at 1,500 pound gross on a hot day, On five cylinders. In cruise flight, if both engines were set to five gallons per hour, they delivered the exact same airspeed. In the same airframe, any airspeed will have a certain pounds of drag to go a set airspeed. To make that many pounds of thrust requires burning a certain amount of air/fuel. The only thing that is different is the percent of available power being used. Larger engines will have more power in reserve for climb, but Zeniths and other typical Corvair powered planes have good rates of climb on 2,700 or 2,775 cc Corvairs. I do not promote any combination which will not have a positive rate of climb on a 100F day at gross weight on five cylinders. All the combinations we sell parts for will meet this criterion.



Above, a 2,850 piston made in the USA, specifically designed for flight engines. The  “2,775 cc”  looks identical, but is .045″ less in diameter and has a different chamber volume.  I wrote a story about having these on the back burner of development 24 months ago, but the project will be done shortly, and they will be an option for builders. read more: Getting Started in 2013, Part #15, 2,775cc.

About William Wynne
I have been continuously building, testing and flying Corvair engines since 1989. Information, parts and components that we developed and tested are now flying on several hundred Corvair powered aircraft. I earned a Bachelor of Science in Professional Aeronautics and an A&P license from Embry-Riddle Aeronautical University, and have a proven 20 year track record of effectively teaching homebuilders how to create and fly their own Corvair powered planes. Much of this is chronicled at www.FlyCorvair.com and in more than 50 magazine articles.

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