Sonex-A purchase - What to look for

[bvolcko38]

" distinct click, 12 per revolution, when you turned the prop slowly over"
Been there. done that.

[Bryan Cotton]

Here is a video of the valves.


hambone had mentioned that in a climb he got over 400, and then cooled to 330 or so. On my Aerovee I rarely get over 300 and I typically cruise with the hot cylinders in the mid 200s. One major difference we noticed was the baffles. They sealed ok against the cowl, but there were a lot of gaps where the sheetmetal met the engine. Not sure if that was as built by Derrick or as redone by the second owner, but the tabs that form the back corners were loose or hacked up. The back right side had a huge gap - you could drive a truck through it. Also the rear baffles were not tucked into the cooling tins. Up front there was a large gap forward of the heads. I think all the time I spent to seal that stuff, either with sheetmetal or a gallon of red RTV, was worth it.

[BRS]

Bryan, I've always wondered how you keep your cyl so cool. Mine (R2300) tend to run about 390 on climb and 360 in cruise (2700-2900 rpm). Oil is around 160. Where are your CHT probes located? My baffles are well sealed and cylinders all wrapped.

[Bryan Cotton]

Bryan, I've always wondered how you keep your cyl so cool. Mine (R2300) tend to run about 390 on climb and 360 in cruise (2700-2900 rpm). Oil is around 160. Where are your CHT probes located? My baffles are well sealed and cylinders all wrapped.

Under the top spark plugs.

[Hambone]

Well, I never thought I’d be stuck for weather in the UHaul, but here I am in Wyoming with winds gusting to 65 mph, and high-sided vehicles <40,000 lb GW prohibited from using I-80. Wouldn’t be so bad, but I’m stuck at a filthy, disgusting truck stop in the middle of nowhere. Nothing to do but wait it out. Winds forecast to abate tomorrow evening. Oh, well..

[BRS]

What an adventure! Think of all the great memories you'll have (once the not so nice ones fade). Stay safe.

[DCASonex]

I recall someone on this forum predicting that your biggest problem moving a Sonex cross country would be the winds. Looks like they were right. :-)

David A.

[Hambone]

Made it home relatively unscathed. The soft padding between the leading edge of the wing and the floor of the UHaul came loose toward the end of the trip, and there is some metal-on-metal damage near the root. It’s a small scratch and dent, aligned with a rib. I checked the airplane at least 20 times during the trip, and that pad was there until I drove into California, where I-80 is in atrocious shape. Why can other states keep their interstates in decent shape, but not California, with their crazy taxes? I’m so ready to leave this state, especially after visiting Pennsylvania and Illinois.

Anyway, I’m hoping the damage is purely cosmetic. Is there any way to pull a small dent out of the leading edge? And how do I determine that the damage is not structural? I’ll be able to see the damage better once we unload the airplane this evening.

[Kai]

Fascinating story, this: most regrettable the flight had to be abandoned prematrurely. But, so far- so good!

IMHO we all need to learn something from this:
1) if one actually must have an engine out situation during a ferry flight, the best place to do so must surely be close to the Cotton family residence, Poplar Grove, IL.
2) the issue with this engine seems to be heat related and in fact overheating with associated issues is something that happens with depresssing regularity to small, aircooled and fairly highly loaded engines. WHY? What are we missing that manufacturers apparently have properly covered? (I can´t recall any instance when heat related issues have been published by manufacturers in factory aircraft). Provided that the engine has been assembled with quality parts according to the book and properly run in- what seems to be the matter with quite a few cooling setups? Air intakes up front and cooling plenums on top seem almost identical on all of them-what else? Cooling air exits too small? Insufficient suction under the engine to get the hot air out? Or is it just that operators disregard factory set temperature limits during flight- or perhaps instrument senders that are either defective and/or improperly positioned?

It would surely be of great advantage to delve deeper into this?

[builderflyer]

2) the issue with this engine seems to be heat related and in fact overheating with associated issues is something that happens with depresssing regularity to small, aircooled and fairly highly loaded engines. WHY? What are we missing that manufacturers apparently have properly covered? (I can´t recall any instance when heat related issues have been published by manufacturers in factory aircraft).

Could it be, at least in part, that the "factory" is located in one of the colder parts of the USA and that their aircraft are not typically flown during the hottest time of the year due to their involvement in Airventure (Oshkosh). Just wondering.

Art,,,,,,,,,,,,,,,,Sonex taildragger #95,,,,,,,,,,,,,,,,,Jabiru 3300 #261