Anyone figure a good way to cool cylinder #3 ?

[pappas]

Of course, the intent is not to cool the probe but the head. The probe happens to be where I may need to direct additional air.

However, your point about the probe being attached to a big thermal mass is interesting, makes sense to me, and I did not consider it. I think you are suggesting that the tiny surface area of the probe, being attached to the large heated mass of the head, causes the probe to primarily measure the temp of the head rather than the temperature of the airflow. The probe's measurement is more representative of the temperature of the larger solid mass. I like it, thanks.

It seems likely that the head would have to run cooler with the additional volume of airflow. Assuming, of course, that the additional airflow has a sufficiently sized and designed exit out of the lower cowl.

Well, I'll probably get on this stuff next week. I'll let you know what happens. Experiment on!

[Scott Todd]

Its all about sharing and learning :)
Its interesting to look across the forums at people having cooling problems. The solutions are always the same.

In summary for future readers:
Clean inlet air with nice radius on inlet lip.
Good baffle seals. Seal EVERY hole/crack.
Clean air thru the heads. Block the big gaps and clean the flashing off those fins.
Minimize inlet air below the baffles. Make sure carb air just goes to carb.
Good exit air. Check the area and follow manufacturers recommendations. When in doubt, open it up a little and try it. Repeat.

This applies to every installation but since this is a Sonex forum, you always hear Sonex say they don't have cooling issues. Look at their posted photos or the actual airplanes. They are simple, clean installations that follow all the above philosophies.

Now get that thing flying so we can see if we can squeeze my skinny ass in for a ride!

[builderflyer]

Its all about sharing and learning :)

you always hear Sonex say they don't have cooling issues. Look at their posted photos or the actual airplanes. They are simple, clean installations that follow all the above philosophies.

!

But in all fairness, the Sonex factory is located in a favorable climate where high OATs are experienced very little of the year. Those of us who live in areas where the OAT is in the 90s and 100s for much of the warmer months have that to contend with, whereas, in Wisconsin our cooling issues would be virtually non-existent.

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

[Scott Todd]

But they still test in the summertime with temperatures around 90. Jeremy and I had this discussion.

BTW, I live in Phoenix Arizona. I don't fly much in the summer and when I do, its usually with a student and early in the morning, I tell them "Climb and maintain 78" :)

And I guess the point was installation. I see lots of airplanes with cooling issues and its always pretty obvious at a glance. But sometimes stubborn homebuilders don't want to hear they did something wrong or need to redo something. Jeremy always laughed about this. Darn he was a good dude...Miss him...

[builderflyer]

But they still test in the summertime with temperatures around 90.

.

Not saying the Sonex factory doesn't make an effort to test for adequate engine cooling on a hot day but given where they are located, they don't have much of an opportunity for that. They have an average of only about 10 days a year where the temp reaches 90 degrees and that's likely near the time of the show when not much testing is being done. Where you live (Phoenix) and where I live (near Redding, CA) 90 degrees is a very cool day in the summer. 100 degrees or higher is the norm. Trying to keep our engines cool for four or more months of the year is a never ending challenge that anyone living in Wisconsin seldom has to face in their typical short summer. Writing this as a long gone Wisconsin native.

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

[WesRagle]

Not saying the Sonex factory doesn't make an effort to test for adequate engine cooling on a hot day but given where they are located, they don't have much of an opportunity for that.

Those who live down south will understand that I chuckled out loud when I read this:

Fall is now upon us, but our AeroVee Turbo test team managed to run an EXTREME Hot Weather Test of the AeroVee Turbo Cooling System in mid-September, and the results are impressive.

OAT: 88 degrees F

Ref: https://www.sonexaircraft.com/aerovee-turbo-cooling-system-report-100318/

Wes

[pappas]

You can only do what you can do, I guess. But here in Phoenix....88 degrees isn't warm enough to go in the pool yet! 72 degrees is sweatshirt weather!

[tps8903]

You can only do what you can do, I guess. But here in Phoenix....88 degrees isn't warm enough to go in the pool yet! 72 degrees is sweatshirt weather!

Hey Lou,

I'm also rocking the turbo. My #3 is also hottest. It's only really and issue on subsequent take offs or go arounds. I suspect the turbo sitting directly behind #3 is contributing to the CHT being high. So I rerouted my cabin heat naca vent and blasted the space between #3 and the turbo. Guess what. Go Arounds #3 is stable with the rest of the Cylinders. Before I had to level at 1000 agl on go sound to not blow through 450f on #3.

This isn't a long term solution, it was just a test to figure out where the heat was coming from.

I'm adding side vents and enlarging the over turbo vent in the top of the cowling. I might build a heat shield with flexible muffler shroud between #3 and the turbo, then force some air in there and up through the top vents to keep the heat around the turbo managable.

I also suffer from excessive ambient temps in the Florida summer.