Sonex-A purchase - What to look for

[Bryan Cotton]

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

And yet - here I am, 101nm south of Sonex, flying through the hottest part of the year. Two summers so far. Currently I'd say our limitation is pattern work, 2 up, when it's hot. Maybe 3 trips around and then go and fly around. I'm going to work on that.

[Hambone]

Well, I’m now on a quest to build up the AeroVee to be as reliable as possible. While I certainly don’t have Bryan’s skills (I think he could build an AeroVee out of toothpicks), I’m ready, willing, and able to learn.

I stuffed the Sonex in the hangar last night with the help of the hangar owner, a friend and A&P. He was quite intrigued by the Sonex and AeroVee, and obviously found them very different from what he works on in his day job at the Diamond Service Center.

For now, I’m taking a short break from the Sonex, apart from learning more about the AeroVee. The last week has been intense, and I’ve neglected too many other things in life.

Thanks again to everyone for the comments, and once again especially to Bryan and Adam for the insane amount of work they did helping me to get home safely.

[N190YX]

I cringe when I see pilots making unnecessarily steep climb outs. Particularly in hot weather, climb at a faster airspeed to get more engine cooling. Steep departures may be fun, but hard in the engine!

[Bryan Cotton]

I cringe when I see pilots making unnecessarily steep climb outs. Particularly in hot weather, climb at a faster airspeed to get more engine cooling. Steep departures may be fun, but hard in the engine!

Amen! 70kts to clear obstacles, normal climbs at 80kts, cruise climb for XC at 90 kts.

Glad you are home safe Hambone!

[Hambone]

I cringe when I see pilots making unnecessarily steep climb outs. Particularly in hot weather, climb at a faster airspeed to get more engine cooling. Steep departures may be fun, but hard in the engine!

Amen! 70kts to clear obstacles, normal climbs at 80kts, cruise climb for XC at 90 kts.

Glad you are home safe hambone!

Thanks!

And the ding in the wing isn’t too bad. It will be a reminder of a crazy 2,000 mile drive!

[Kai]

I was at pains not to mention any particular brands in my first posting, but since one make has already been brought forward by others I could just as well mention another one from way down south in another continent. They manufacture complete airplanes and also sell their engines to E-AB´ers. To put it carefully, they have put a lot of design effort into their own cowlings. As a result their own aircraft generally perform as advertised without a pletoria of hair raising engine heat issues, whereas the E-AB engines seem to suffer far too much from this ailment, notwithstanding the fact that their findings have been published in their comprehensive installation manual. I wonder why- maybe we are just to lazy to adhere to their suggestions?

Taking this one step further and looking at (very expensive!) european brands of VW-1 aeroderivatives, they seem to do quite well in airframes specifically designed for them (but throw away the heads after 500 hrs flight time!) Once years back I attended an engine course for one such specific brand. It was made quite clear that the original VW cooling fan would force feed 900 l/min of cooling air through the fins on heads and cylinders at full tilt and at a heat load of some 40-50 HP. Nedless to say, such a mass of cooling air is as good as unattainable in our slow moving airplanes- yet we flog out almost twice that power in continuous cruise settings! Let´s face it- adequately cooling these engines takes a lot of dedicated work by properly informed and well trained expertise. A couple of weekends around the patch with a factory (any factory!) supplied cowling having nice looking air in- and outlets, is far from sufficient.

[karmarepair]

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.

"Pops A Dent" glue puller and patience, and you'll never know the dent was ever there. And you can look in the wing root with a flashlight and an inspection mirror to look for "tripping" of the ribs, but if the visible dent is not ON the ribs, internal, structural damage seems exceedingly unlikely.
Pictures?

[karmarepair]

On cooling http://bobhooversblog.blogspot.com/search?q=cooling
Gone now, but "Veeduber" flew an Aeronca C-3 with an 1100 cc VW BEFORE 1960, and may have been the first person in the USA to fly behind a VW. He built and sold VW aeroengines for a while, had strong opinions, and was a friend and a mentor to me. Also check out his HVX modifications, to put more oil in the heads around the valves to carry off heat, for the VW is as much Oil Cooled as Air Cooled. A typical Aerovee DOES NOT have these mods, mine has a FEW of them.

Pressure differential between the upper and lower plenum should be about 9 inches of water at full power, which a well designed and implemented "firewall" forward should be able to easily achieve at about 100 MPH.

John Monnett has a lot of hours behind VW aeroengines, and had the help of Claude of Claude's Buggies (now CB Performance) and his sons, both pilots, in the development of the ORIGINAL AeroVee (for the Sonerai) and the AeroVee 2.0, but he did some things that made me wonder. The first iteration of baffles on the Sonex Aerovee were Not Very Good; the current "fence" baffles are much better, IMHO. The needed lip for the cowling outlet is NOT in the plans set, but is rather in the instructions for the cowling, and are easy to miss. The oil cooler inlet for the Cooler Under The Sump arrangement has a tendency to pressurize the LOWER plenum, sapping the pressure differential. Someday, I'll change my airplane over to a top mount cooler, but I want to fly it first - we are close. This year.

Another issue has been the heads themselves, particular the aftermarket, drag racing oriented ones. They often did not have adequate airflow around the exhaust valves. The heads AeroConversions sells now are based on Chinese sourced EMPI castings and are as good as the Original German heads that have been unavailable for 25 years.

Searching this forum and a lot of Aerovees have burnt valves and cracked heads in frightfully short periods of time, but plenty of others have gone hundreds of hours with little trouble.

[Kai]

Eh- well, yes: that´s it, then!

You´re more to the point than I am: I hope that both your posting and Mr Hoovers blog is read by all VW-1 flyers- and especially Hambone.

And thanks!
Kai

[daleandee]

On cooling http://bobhooversblog.blogspot.com/search?q=cooling
Gone now, but "Veeduber" flew an Aeronca C-3 with an 1100 cc VW BEFORE 1960, and may have been the first person in the USA to fly behind a VW. He built and sold VW aeroengines for a while, had strong opinions, and was a friend and a mentor to me. Also check out his HVX modifications, to put more oil in the heads around the valves to carry off heat, for the VW is as much Oil Cooled as Air Cooled.

You might wanna be careful bringing Bob into the disscussion as some here might learn things they didn't know and others might well be offended. I believe his "Christmas Engine" story is a good read for an honest approach into reality:

https://bobhooversblog.blogspot.com/200 ... ngine.html

Dale
3.0 Corvair/Tailwheel