AeroVee Turbo - Initial OSH trip report

[MichaelFarley56]

Now that AirVenture 2015 has wrapped up and everyone has (hopefully) made it home safely, I wanted to offer a quick summary of my trip this year as it was the first long trip I’ve made with the turbo AeroVee. I plan on writing a more detailed report for the next Foundation newsletter, but I got a lot of great turbo related questions while at AirVenture so I thought a quick summary would be in order.

First off, I’m happy to report that the engine ran beautifully the entire time. I never had a single hiccup, hesitation, sputter, etc. the entire duration of the trip. Before I left Ohio I had only been able to run the engine around 12 hours, so I was also hoping to use the trip to keep getting time on the cylinders and help continue the break in process. As a result I was still forced to keep the mixture pretty rich for low cylinder head temps but I was happy to burn a little extra fuel to keep everything running nice and cool. The only item to address at this point is my oil pressure; prior to adding the turbo my oil pressure was rock solid at 48-50 psi, but after adding the turbo it now generally runs around 40-42 psi. It’s still “in the green” and I knew it would be a little lower due to the hot temperatures keeping my oil in the 170-180 degree range (I briefly saw as high as 198 on a climb but after I leveled off it came back down to 175) but I’d still like my oil to be at least in the mid 40’s psi wise.

On the flight up to Oskhosh, I flew as a flight of 2 and we left mid-morning the Saturday before the show. Due to the low ceilings and visibility we were forced to stay below 2500’ MSL the entire trip and had to endure the hot air temp the entire way. The wind was not in our favor either so we ended up making two stops for fuel, ultimately arriving at Oshkosh around 1:30 p.m. local time.

At these low altitudes I was running the engine around 30” MAP which gave me around 3150 RPM, 130-135 MPH TAS, all while burning 7 gallons per hour.

The good news was that the CHTs never got over 385 in climb and were steady right at 355-360 degrees in cruise. I am currently using a Prince P-Tip prop that is 54x50” which seems to be slightly pitched more for climb which was nice on takeoff. Between myself, all the camping gear I could carry and full fuel, my takeoff weight was right at 1100 lbs. and even with the really hot air temps, my initial climb rates were around 700 feet per minute. Not too shabby!

On the return trip home, I was able to shed some of the camping gear and climb a little higher so naturally my cruise numbers were a little better. When running at 4500’ MSL and around 100 lbs lighter, I ran the engine at 30” MAP which gave me 3200 RPM, 140 MPH TAS, and fuel burn was slightly lower than before. CHTs were all very steady at 350 degrees with an average EGT of around 1200 degrees.

Overall, I’ve been thrilled with the turbo addition to the AeroVee. In my opinion the engine runs much smoother and stronger than before, and climb rate has been drastically improved. Using the Prince P-Tip 54x50 I can get some really excellent climb rates while still getting respectable cruise speeds. It’s really nice having all CHTs run within 5-7 degrees of each other and EGTs are normally within 15 degrees of each other as well.

Stand by for a more in depth report in the next Foundation newsletter, but if you have any questions in the meantime, please let me know!

[kevinh]

Thanks for the great write up!

[Rynoth]

Great report, thanks Mike.

[vigilant104]

Mike,
Thanks for the report. Are you measuring fuel flow in real time these days, or doing the math when you fill up?

I always look forward to hearing more about the turbo!

[Schmleff]

I wonder if you are foaming the oil with the turbo oil scavenge pump resulting in lower oil pressure? Just spitballing ; )

Now that AirVenture 2015 has wrapped up and everyone has (hopefully) made it home safely, I wanted to offer a quick summary of my trip this year as it was the first long trip I’ve made with the turbo AeroVee. I plan on writing a more detailed report for the next Foundation newsletter, but I got a lot of great turbo related questions while at AirVenture so I thought a quick summary would be in order.

First off, I’m happy to report that the engine ran beautifully the entire time. I never had a single hiccup, hesitation, sputter, etc. the entire duration of the trip. Before I left Ohio I had only been able to run the engine around 12 hours, so I was also hoping to use the trip to keep getting time on the cylinders and help continue the break in process. As a result I was still forced to keep the mixture pretty rich for low cylinder head temps but I was happy to burn a little extra fuel to keep everything running nice and cool. The only item to address at this point is my oil pressure; prior to adding the turbo my oil pressure was rock solid at 48-50 psi, but after adding the turbo it now generally runs around 40-42 psi. It’s still “in the green” and I knew it would be a little lower due to the hot temperatures keeping my oil in the 170-180 degree range (I briefly saw as high as 198 on a climb but after I leveled off it came back down to 175) but I’d still like my oil to be at least in the mid 40’s psi wise.

On the flight up to Oskhosh, I flew as a flight of 2 and we left mid-morning the Saturday before the show. Due to the low ceilings and visibility we were forced to stay below 2500’ MSL the entire trip and had to endure the hot air temp the entire way. The wind was not in our favor either so we ended up making two stops for fuel, ultimately arriving at Oshkosh around 1:30 p.m. local time.

At these low altitudes I was running the engine around 30” MAP which gave me around 3150 RPM, 130-135 MPH TAS, all while burning 7 gallons per hour.

The good news was that the CHTs never got over 385 in climb and were steady right at 355-360 degrees in cruise. I am currently using a Prince P-Tip prop that is 54x50” which seems to be slightly pitched more for climb which was nice on takeoff. Between myself, all the camping gear I could carry and full fuel, my takeoff weight was right at 1100 lbs. and even with the really hot air temps, my initial climb rates were around 700 feet per minute. Not too shabby!

On the return trip home, I was able to shed some of the camping gear and climb a little higher so naturally my cruise numbers were a little better. When running at 4500’ MSL and around 100 lbs lighter, I ran the engine at 30” MAP which gave me 3200 RPM, 140 MPH TAS, and fuel burn was slightly lower than before. CHTs were all very steady at 350 degrees with an average EGT of around 1200 degrees.

Overall, I’ve been thrilled with the turbo addition to the AeroVee. In my opinion the engine runs much smoother and stronger than before, and climb rate has been drastically improved. Using the Prince P-Tip 54x50 I can get some really excellent climb rates while still getting respectable cruise speeds. It’s really nice having all CHTs run within 5-7 degrees of each other and EGTs are normally within 15 degrees of each other as well.

Stand by for a more in depth report in the next Foundation newsletter, but if you have any questions in the meantime, please let me know!

[MichaelFarley56]

I'm not so sure about foaming oil given the design of the system. Once the oil leaves the upper oil galley it passes through the turbo housing then gets pumped back into a valve cover. Pretty simple! I do wonder though if the scavenge pump side of things affects oil pressure readings at all. As I said, I'm not too concerned about it!

Mark, when are you coming back over to check out the turbo installation? I hope you're making good progress on getting your Sonex back in the air! Hopefully we can meet up here soon.

[SonexN76ET]

Mike,

The lower oil pressure could be because of the hotter oil coming back from the turbo or it could simply be from the oil having to travel through the oil lines to the turbo. I noticed when I went from the standard bottom mounted oil cooler to the top mounted oil cooler, my oil pressure increased by 10 psi. I believe this is because of the oil not passing through the oil lines to the bottom mounted cooler.

I saw the mass taxi video of you going by with your plane. That turbo sure sounds good!

Jake

[mike.smith]

FYI, my oil pressure has been around 32 psi for the 100 hour life of the engine. VW folks say that 10 psi per thousand rpm is good. Sonex said as long as that number does not begin to decrease, I am fine.

[Gripdana]

I have the top mounted oil cooler, no turbo. I see 72 psi at 3200 rpm and 25 to 30 at idle. I am using the VR1 20w 50 oil. The oil temps are from 190 to 205. The outside air temperature in the Mojave desert has been in the mid 80's to 100 degrees while flight testing.

[mike.smith]

FYI, my oil pressure has been around 32 psi for the 100 hour life of the engine. VW folks say that 10 psi per thousand rpm is good. Sonex said as long as that number does not begin to decrease, I am fine.

I should amend that: 32-35psi is normal for me, with oil temps that rarely exceed 180 deg even on a warm day (in the winter I need to use blank off plates of varying sizes to allow the oil temp to even come up to something above 120 deg). Bottom mounted oil cooler.