PFH Sonex B

[pfhoeycfi]

I was experiencing very high CHTs, especially on #3, with my Turbo Aerovee since the warm WX arrived. This high (p) side is what it is so I made the low side lower...see pic. The improvement far exceeded my expectations. That is a 30 deg angle, 3/4" high, closed ends. CHTs are all in line now and the temps are lower. The oil cooler performance has improved as well. I'll do more testing but so far so good...

peter

[Bryan Cotton]

Nice!

[T41pilot]

I have the Turbo and my #3 is also the hottest. I'll be following your updates on this mod. Is this installed on both sides? I'm assuming at this point there might be a small drag penalty but quite frankly a mile or 2 an hour loss is well worth a cooler happier engine to me in my opinion. I'm currently test running the under cowl naca vent mod pointing some outside air at the aeroinjector to keep the engine from quitting at roll out after landing. Have only 1 flight with that so far so no conclusive result yet. My engine seems to be fine in other respects during the flight other than I have to cruise climb most of the time to keep #3 under red line. Once in cruise the temp comes down fine.

[pfhoeycfi]

I have the Turbo and my #3 is also the hottest. I'll be following your updates on this mod. Is this installed on both sides? I'm assuming at this point there might be a small drag penalty but quite frankly a mile or 2 an hour loss is well worth a cooler happier engine to me in my opinion. I'm currently test running the under cowl naca vent mod pointing some outside air at the aeroinjector to keep the engine from quitting at roll out after landing. Have only 1 flight with that so far so no conclusive result yet. My engine seems to be fine in other respects during the flight other than I have to cruise climb most of the time to keep #3 under red line. Once in cruise the temp comes down fine.

Yes, both sides. I have no prob with heat effecting the aeroinjector. My fuel line from the firewall to the aeroinjector is about 6 inches, if that, double insulated w firesleeve. No burbs, hiccups or stalls.

[T41pilot]

I have the Turbo and my #3 is also the hottest. I'll be following your updates on this mod. Is this installed on both sides? I'm assuming at this point there might be a small drag penalty but quite frankly a mile or 2 an hour loss is well worth a cooler happier engine to me in my opinion. I'm currently test running the under cowl naca vent mod pointing some outside air at the aeroinjector to keep the engine from quitting at roll out after landing. Have only 1 flight with that so far so no conclusive result yet. My engine seems to be fine in other respects during the flight other than I have to cruise climb most of the time to keep #3 under red line. Once in cruise the temp comes down fine.

Yes, both sides. I have no prob with heat effecting the aeroinjector. My fuel line from the firewall to the aeroinjector is about 6 inches, if that, double insulated w firesleeve. No burbs, hiccups or stalls.

My fuel line is short and fire sleeved but just lately my engine has quit after landing a couple of times as some others have reported. It idles fine during short flights or after warmup before takeoff. Didn't do it earlier this spring so the extra oat heat must be it. I'll see if the under cowl mod helps me. Seems to have worked for others.

[Onex107]

I had the same idle problem after flying in my Onex and I think it applies to you as well. My Aerovee didn't completely die as I taxied. It surged. Like it would go leaner and then back to richer. I suspected heat to be the problem after solving the burp problem with insulation of the fuel line. But, I also had firewall failures of the voltage regulator and one of the ignition coils. So I added a blast tube from the front of the baffle, down to the AeroInjector with a nozzle that directed the outside air to the end of the uninsulated slide valve, not to include the air filter. I didn't want to pressurize the inlet. The next flight, and for several hundred hours more, the surging problem disappeared and the engine Idled fine on hot days.

[Bryan Cotton]

I'm assuming at this point there might be a small drag penalty but quite frankly a mile or 2 an hour loss is well worth a cooler happier engine to me in my opinion.

Amen!

My engine seems to be fine in other respects during the flight other than I have to cruise climb most of the time to keep #3 under red line. Once in cruise the temp comes down fine.

I also do a lot of cruise climb. But I find the airplane climbs pretty well at 90kts. I get stumbles on the ground when really hot, but otherwise it's good. Worst is after it's hot, I stop for fuel, and then start & taxi back. I suspect if I can get my oil temp below 200 this problem will go away.

[pfhoeycfi]

My aerovee turbo cooler pump failed recently. I found a replacement pump direct from toyota. Works great. I also wanted a way to confirm that the pump is working, other than looking in the catch can when the top cowl is off. I installed a 1/8" 300 deg F Vdo sensor in the hose leaving the radiator, wired to the MGL MX1. The temp feedback provides a really good indication of what the turbo cooler system is doing, especially after engine shutdown. It was def worth the effort.

[pfhoeycfi]

EAA test card 17 has one trim the airplane at 3 different speeds and push the nose over and increase the speed to plus 20, let go of the stick and count the number of oscillations to return to the trimmed speed. I can trim to any speed, but the plane does not want to return to the trimmed speed per the test. Has anyone else seen this in testing? Is this just the way the Sonex behaves?

Peter

[Bryan Cotton]

I didn't do that card. But I can confirm my Waiex has similar characteristics.