Siezed low-time neglected turbocharger

[lutorm]

Hey Jerry. I just came across an excellent white paper by Garrett on water cooling. You need to read this.
https://www.turbobygarrett.com/turbobyg ... ooling.pdf

I guess you missed that being linked back on page 7 of this thread. ;-)

[markschaible]

Hello SonexBuilders.net and Happy New Year!

We see that this forum has been quite busy during our holiday break, and we want to address some of the current discussions regarding the AeroVee Turbo.

• Sonex has conducted turbo body temperature testing in test cell and flight. Time in service has shown post-shutdown heat-soaking is causing the issue of coking oil and therefore turbo sticking.
• The reason that full synthetic oil is not approved is because it is not compatible with leaded AvGas since it does not contain detergents that keep lead in suspension. Full synthetic oil can be used with the AeroVee and AeroVee Turbo if unleaded auto fuel is used. (note that Rotax turbos are required to run auto fuel and full synthetic oil). AeroVee Turbo operators may want to consider switching to 91 octane auto fuel and full synthetic oil to help alleviate coking.
• Sonex plans to expand auto fuel testing with the AeroVee Turbo as-well (as weather permits).
• Note that we still recommend frequent oil changes as prescribed in the AeroVee Turbo manual, even with synthetic oil, and more frequent oil changes may also help alleviate the problem.
• Sonex is prototyping a simple liquid cooling system for the turbo to help prevent coking so AvGas and partial-synthetic oils can continue to be used. We will keep you posted.
• The question regarding bearing type came up in the discussion thread: The AeroVee turbo unit uses journal bearings. Journal bearings must be used with the carbon seals we use, and the carbon seals are vital to keeping fuel out of the bearings in our pull-through installation. If rebuilding your turbo, make sure that only carbon seals are used.

We encourage all current AeroVee Turbo operators to continue contacting us directly with your questions and feedback to tech@sonexaircraft.com

[Brett]

Anyone have some thoughts about this oil?

http://www.penriteoil.com.au/products/c ... -pao-ester

Says is fully synthetic and compatible with Avgas.

I’ve emailed the oil company’s tech support. Will see if, or what they respond with and will post back here.



Adding maybe a bigger version of this too ?

https://hobbyking.com/en_us/hobbyking-l ... iator.html

Or perhaps


http://www.performance-pcs.com/lepa-aqu ... i-240.html


Last but not least


https://m.aliexpress.com/s/item/3281483 ... t#autostay


With maybe something like this to turn it off automatically after 5 -10 mins

https://m.ebay.com.au/itm/Microcomputer ... 2140903831

[lstinthot]

My plan for the turbo at the moment is to add water cooling with a small radiator mounted lower than the turbo and the reservoir mounted well above the turbo for passive cooling. I really want to see how little cooling fluid I can get away with. If it works that will probably be my cabin heat source too.

I think you want the radiator above the turbo. The idea is that hot water from the turbo will rise into the radiator and cool down, setting up a thermal siphon. The Garrett white paper referenced earlier in the thread talks about how to facilitate this self-circulation.

This is correct. The hotter water is less dense than the colder water. As the water cools it becomes more dense (heavier) and therefor will want to go down. In a closed loop, its this heavier water that is driving the other leg back up into the radiator. The Radiator needs to be the high point in the system. We use this principle in the power plant for natural circulation. Our Steam Generators are higher than the reactor just in case the reactor coolant pumps fail we can generate enough natural flow to keep the reactor cool. Heat sink higher that source, minimize bends and use as large of tubing as possible to reduce friction.

Best of luck

[jerryhain]

That all sounds reasonable, I’ll put the filler just above the radiator and all of it above the turbo.

[pfhoeycfi]

Passive circulation hot water heating systems were once a thing...my sister's house still has it. Boiler in the basement, big ole radiators throughout the upstairs...no pump. Pumps are used today of course, allows for smaller equipment, terminal units, etc for the same heat output.

[Area 51%]

My 1941 John Deere "B" had convective cooling. No water pump and no pressure cap. There was, however, a shaft that ran from the magneto drive to the radiator that turned a fan. There were also shutters in front of the radiator that could be opened or closed from the driver's seat to control the coolant temp. This was on an engine that was designed to work hard all day.

As a side note...........it had no electrical system and had to be "hand propped".

[Brett]

The oil company emailed me back. We exchanged probably 6 x emails until they finnaly wanted to know what the engine was in. So as expected I told them an experimental aircraft and they ceased all form of help due to their company policy in regard to aviation. They did say it was suitable for avgas but not at 25 hour service intervals..

So essentially back to square one...

[SvingenB]

Ok well this thread has taken some interesting branches. I love the UL motors. Really beautifully built and quality. My comment was actually very logical. If i was to have a UL motor i would have two alternators and 2 batteries.it wouldnt be hard to do. Why ? well if you have an electical failure you loose yor spark. Old skool technis good too . Carbs, mags have been refind over the years, self contained , and actually very reliable. Yes efi and electronic ignition takes it to a whole new level. For me, im very conservative regarding safety. Redundency is your lifeline.

I don't disagree, but how much redundancy do we need? An alternator and a battery is already a redundant system as far as electrical power is concerned. Two old fashioned mags isn't really that different from two alternators, excluded the batteries, except two modern alternators are more reliable that two mags. Solid state electronics are as reliable as it gets.

I think UL also comes with double alternators if requested though.

[Waiex 49]

Dual alternators are nice, but not an option for all engines.
My "all electric" Viking engine runs a single alternator and dual batteries for "redundancy".
If the single alternator goes out (I do have a warning light installed) I will have plenty of battery life to run fuel pumps and FADEC systems while I scout an airport to land at.
With the new, modern lightweight batteries it is very feasible to run dual batteries.