Aerovee Turbo Kit

[MichaelFarley56]

Good question Ryan. While I'm certainly no expert on fluid dynamics, I do think there may be a slight apples to oranges comparison when looking at turbos in the automotive world as compared to aviation use.

In a car, while it's true you do have liquid cooling, you normally ask a lot out of the turbo right up to the point you shut the car down. We drive at highway speeds, accelerate as we take turns, then as soon as we throw the car in Park we shut the engine down. This happens while the turbo is still really hot and if it wasn't for the coolant to absorb that radiant heat, the turbo bearings would probably go bad quickly.

Now if we look at airplanes, we obviously don't have coolant running through the turbo housing so things change a little. In this case we rely on oil passage to cool things down and this takes a few minutes, hence the thought of turbo cool down times. Having flown a lot of different turbocharged airplanes, I've generally been taught to pull into your parking spot or in front of your hangar and then let the engine idle for at least 3-5 minutes. This allows oil to absorb that radiant heat, thus cooling things before we shut down. Don't forget, after we clear the runway and taxi we're generally at idle so taxi time is serving the same purpose.

I've flown behind turbo'd Lycomings and Continentals for years without liquid cooling....I have no doubt that if we treat our AeroVee turbos gently, they'll be fine as well. I'm certainly planning on turbo cool down idle runs as part of each flight for just this reason!

Just my two cents of course!!

[jerryhain]

Sounds like an opportunity for cabin heat to me.

[MichaelFarley56]

Hey Everyone,

I haven't posted an update on the turbo upgrade project, so I wanted to take a second to show my progress. After receiving the turbo kit, new heads, and other parts I was finally able to start work on things in early January. Thus far, I've removed the old heads and Nikasil cylinders, old connecting rods, exhaust, intake, battery box, etc. My engine has been rebuilt with iron cylinders, the new turbo oil pump, and exhaust manifold:



The turbo has been mounted after wrapping the exhaust manifold and turbo downpipe. There's not a whole lot of room between the turbo and firewall but everything looks good thus far.



The intake tubes are installed and fit well. They take a little tweaking for proper fit but the silicone tube connectors allow for a little flex.



Finally, I now have the intake tube and Aeroinjector mounted.



Next steps will be installation of the new battery box, starter solenoid, and voltage regulator before I begin fabricating the turbo oil supply and drain lines. Then I'll need to modify the baffling, connect sensors, etc. I'd really like to have the engine running this month but we will see!

Thanks!

[Waiex 176]

Thanks for sharing your progress. I will be going through this process in the next few months. I'm starting to gather parts. Since I too have the nikasil cylinders, I've ordered new cylinders, pistons and head gaskets. I was curious if you had to get new push rods or if you were able to use the old ones? Is there anything else I will need?
Thanks
John N176WS

[Gripdana]

Mike,
Thanks for the photos and report. That really helps to see what is involved in the change over. When you are done can you let us know how much time it took to do the turbo install? Do you have a photo of the fire wall under the turbo housing? I'm wondering how much I need to move on the firewall.

[kmwoody]

I didn't think about this earlier when builders were talking about the lack of clearance behind the turbo, but did anyone notice the large number of mount shims the companies turbo had? I took pictures of them at Airventure, but they turned out blurry. They have at least 8 or 9 washers pushing the engine forward. I wondered why they had done this, now it seems for turbo clearance.

I will try to post the picture.

[img]20140731_124128.jpg/img]

Ken W
Sonex 959
Aerovee 288 hrs

[MichaelFarley56]

I've tried to take a few pics of the turbo in relation to the firewall...I hope these pics help answer that question.





To help clarify, you do not need to add any additional washers as spacers on the engine mount. The turbo is a snug fit but it does fit just fine. There's perhaps 1/4" of clearance between the turbo and the firewall at the closest point, but there's still enough room for the turbo blanket (heat shield) between the turbo and firewall. Also, the turbo is perhaps 1/4" from the starter housing as well but again, it's not an issue.

Needless to say things are snug, and after working on this I give all the credit to the Sonex factory guys for making a snug yet completely useable add on kit. They had limited amounts of room to work with but made a tidy and effective package.

I will keep offering updates as I'm able. At this point I'm not really sure how many hours I have into the upgrade package (not really counting) but I'd guess I have 5 hours into the new cylinders and heads, and another 10 on everything else I've done. That includes removing the old battery box, removing the voltage regulator and master solenoid, so there's a lot of work I've done others many not need to do. And with regards to the valve pushrod question; as long as you're not changing compression on your cylinders, I see no reason why the "old" ones won't work. The Nikasil and Iron cylinders seem to be the same size.

If anyone has any more questions please let me know! I can't wait to get this done and get the engine running!

[tmobbs]

Gearry

I have been looking again at the pictures posted of your turbo-vee installation on 19 December at 14:38.

The fourth picture appears to show your Usher Gascolator mounted as per the Sonex diagram and quite close to the turbo exhaust.

Firstly, is proximity to the exhaust an issue?

Secondly the photo appears to suggest that the gascolator is well below the carby. This means that for the final few inches the fuel is required to travel "up hill". Have I understood that correctly or is it an artefact of the perspective of the photo? And if the fuel IS required to go up hill to the carby, have you had any problems -e.g. the burping that is often mentioned in the forums?

Best wishes

Tim Mobbs
Sonex #1555 & Aerovee #0672

[Rynoth]

Tim, it's actually required that the gascollator be the lowest point in the fuel system, and that the line running from gascolator to carb be continuously "uphill" to prevent bubbles from collecting in the "peaks" in the fuel line (ie vapor lock).

[marsolgp]

Hi Tim,

Ryan is correct, the gascolator is the lowest point in the fuel system and was mounted per original plans from Sonex. I do not know exactly how far the exhaust is from the gascolator, maybe 8-10" at the closest, but it has had no ill effects on the fuel system. That exhaust wrap is very effective at stopping radiated heat.

Now as for 'burps'… not to start a war here, this is just my experience: since I replaced the AeroInjector with the Rotec TBI, I have not had a single 'burp' or stumble or anything that resembles vapor lock issues. When I had the AeroInjector on I was constantly chasing down burps and stumbles, etc. I removed the F/F transmitter, wrapped extra insulation around the fuel lines and gascolator, I wrapped the exhaust system, I even installed a blast tube to the gascolator and nothing seemed to help. Once the Rotec TBI was installed everything smoothed out. I haven't had a burp or stumble since. I reinstalled the F/F transmitter, took all the ugly insulation off the fuel lines and gascolator (I still have fire sleeve on the fuel lines), removed the blast tube and so far (50+ hours) all has been fine.

I do have a fuel pump in the system, since the TBI installation, but have only used it for priming on initial start of the day. During flight, the pump has never been turned on…. it'll be nice to have if I ever run into vapor lock issues…. I will let everyone know if I run into any issues as we get into summer months.