SonexBuilders.net

-----

Mike:

Looking at your first flight photos, I noticed you are flying without the gear fairings and wheel pants. Sonex recommends always flying with them, especially with the AeroVee. There are some pretty stunning differences in the speed numbers with and without. Less speed (in this case) means more drag. More drag means the engine is working harder and has a greater tendency to overheat. Probably not your issue with #3, but it all helps keep the numbers under control. Something to consider before your next flight.

Mike Smith
#439

Just a thought...Are you using the Sonex recommended location to measure CHT or the "under the plug" type of thermocouple ring...If under the plug type, then maybe your measuring the temp of combustion gas leaking...There's evidence to suggest the under the plug location yields higher CHTs.

-----

Mike,

First off, great job flying the airplane and making it a successful first flight! It's easy to get distracted with small details and miss the bigger picture.

For for your hot cylinder, if the rest of the cylinders were all the same, you may simply have a bad CHT probe. You could always swap two probes and see if the same cylinder stays hot.

Did you get a reading on what your EGT's were?

Finally, with regards to the RPMs. What is your static RPM and what did you indicate on climbout? My AeroVee has a higher static RPM on the ground vs. what I see on climbout. If you're indicating anything over 3000 RPM on climbout I wouldn't worry too much at this point. It should get better as your engine breaks in.

Great Job!

-----

Mike, I had the same problem, only on the left side. The two left cylinders would go hot and the engine would run very rough. After a good look at everything, my Sonex friend and I discovered that the coil wires on the left and right bottom were switched. I guess when plugging them in, facing the coils, left was right and right was left. The switch solved the problem.

-----

Fastcapy wrote:After reading things from other builders on the various web resources I turned off my secondary ignition after the run up. I had much better performance.
My temps dropped on the #3 cylinder by about 15deg. It was still around 425, but that is better than the 440 I had on the first flight.

Sounds to me like your secondary ignition is advanced. I'd retard it a little and try again. I think you'll find that the temps will stay where they belong.

Fastcapy wrote:A couple things I noticed. FIrst I was so much less nervous this time which made the flight more enjoyable.

That's typical. The emotion of the first flight is behind you now and you are more relaxed. Very common.

Fastcapy wrote:My landing was still a little bouncy, I think my problem is that my tailwheel time is in a Rans where I sat a lot higher off the ground and I am flaring to high in the Sonex because I am not yet use to the sight picture.

This is VERY common. Just about everybody I've flown with has had the same problem. It's easy to flair too high until you get used to how low the airplane sits and how quickly it reacts to the elevator input in the flair.

Another thing people tend to do is over-rotate in the flair. It's very easy to do this too, and will result in a bouncy landing. Pay attention to the three point attitude while you're taxiing the airplane and look for that EXACT same picture in the flair. Once you see that attitude, don't pull back on the stick any farther. Just hold that sight picture until the airplane touches down. Works like a charm!!

Enjoy, and do it safely!!