Siezed low-time neglected turbocharger

[markschaible]

Hello SonexBuilders.net!

Sonex Aircraft is pleased to report on the preliminary results of our testing with a liquid cooling system for the AeroVee Turbo’s turbocharger bearing block.

Summary of system and testing results:

• Max bearing block temperatures of approximately 211 degrees – a dramatic 118 degrees F reduction in maximum bearing block temperatures from the original AeroVee Turbo configuration (an approx. 60 degree reduction in temperatures from the current configuration per ACV-SB091616-1B and current AeroVee Turbo installation manuals).
• Total system weight under 5 lbs with coolant.
• Radiator location is flexible for tighter installations such as the Onex or Legacy Sonex Aircraft.

See the full, detailed report with pictures and data on the Hornets’ Nest R&D web site at: http://www.sonexaircraft.com/research/updates/aeroveeturbo/aeroveeturbo_update_020618.html

We will continue to post new testing data and details of system availability in the coming weeks as our work on this project progresses.

--
Mark Schaible
General Manager
Sonex Aircraft, LLC
phone: 920-231-8297
fax: 920-426-8333
http://www.SonexAircraft.com
http://www.AeroConversions.com

Sales Info: sales@sonexaircraft.com
Orders: orders@sonexaircraft.com
Accounting: accounting@sonexaircraft.com
Tech Support: tech@sonexaircraft.com

[drPete]

A thorough report from the Hornet’s nest. A customer focused research project with actionable information. Expected nothing less, thanks Mark.

Timely for me, mounted the turbo last weekend.


Sent from my iPhone using Tapatalk Pro

[NWade]

While I understand the continued frustrations of some, I think its better to see action - and most importantly, data - from Sonex than to see nothing at all. And I am glad that a parts list is going to be made available so that Turbo owners can source their own materials if they so choose.

So thank you to Mark and the Sonex folks for working on this solution.

I look forward to seeing the results of flight tests, tests conducted in different weather, and - most importantly - simulated failures of the electric pump and the cooling fan. I'm very curious to hear whether the coolant will flow if that pump loses power or seizes up. I am curious to hear if this happens in-flight whether the coolant overheats and causes other FWF problems. If the pump passing fluid in-flight turns out to be important, then I am very curious to know if there is an easy way to tell in-flight whether the pump is turning or not (via direct or indirect measurement).

I look forward to the next report!

--Noel
P.S. One thing that really stands out from the data is just how long the turbine housing stays above 400 degrees. That hunk of iron has a tremendous amount of thermal mass!

[hollandvw]

This sounds like great news for taiming the turbo and making it more durable. Glad to see the effort to correct this issue.

[MichaelFarley56]

While I don't except any answers right off hand (I know testing continues which is great news!), I also have a lot of questions on this potential fix in addition to Noel's excellent ones already posted. Perhaps, in time, these other questions can be answered as well.

In addition to the component failure questions already asked (What happens on the event of a coolant leak? Pump failure? etc.), will there be provisions to monitor coolant temperature? I understand FAR 91.205 states a coolant temperature gauge is only required if the entire engine is liquid cooled, but will this setup also have temperature monitoring? What about fan operation? Will there be some sort of light to indicate when the fan is working? It sounds like there may be some sort of thermostat fan switch for control; perhaps something like an ON-AUTO-OFF capability?

Will there be options on different radiator sizes and shapes to best fit different positions under the cowling? Your radiator's current location may work on a B model, but I'm seriously doubting that will work for a Legacy model.

How much coolant fluid does the system hold?

How much additional weight is being added to the engine? If it's under 5 lbs, that's great, but how much weight is it?

How much beta testing is currently being planned? Are you going to ship several kits to current turbo owners for testing?

Is this going to end up being a Mandatory Service Bulletin? What will happen to ACV-SB-091616-1B since, according to this literature, it's proven to be at least partially ineffective? Do turbo owners still need to follow it? Also, since this is Mandatory, will this be offered for free or deeply discounted to customers who already have purchased a turbo kit?

Again, no need to answer these questions immediately (and I'm sure others will chime in with other questions anyway). Thank you for keeping us in the loop on your project!

[John Monnett]

Please go back and read the report... most of your questions are answered. The system is controlled by a thermostat
and the switch. It works best on automatic but may be run on manual. The neat thing is that you can walk away and let the system shut down on it's own when it has cooled down. Total coolant is about 1 pint and the header tank has a pop-off cap and drain incase of over pressure. The coolant boils at 375º. Even when the system is at max temp we can remove the cap (something you would never do with an auto radiator). The data shows that the system works without the fan or pump (in case of a failure) but we only intend only to run the system on the ground after shutdown when we no longer get cooling from the oil system. The pump is a vain type so coolant will pass through if it malfunctions. The system is set up to work with convection cooling... no fan, no pump... but not nearly as efficient as when the pump and fan are employed. As always, the weight will very with the installation due to hose length, mounting hardware etc. Like so many other things, installations will be "custom" to each aircraft. Certainly, we are breaking new ground with this very simple system. No data or plans for an independent turbo cooling system exists to our knowledge so I believe we have made great strides to improve our turbo installation. I urge, no, challenge you to find data on other turbo installations like Continental, Rotax (which runs on auto fuel and synthetic oil) etc, and find what they have done to eliminate coking. Funny how very few question the cooling system on a Rotax or it's un-cooled turbo. Stay tuned.

[Spinnetti]

This may have been already covered, but what about a temp controlled fan over the turbo once you shut down? Would simple air cooling be enough? I like the liquid cooling, but seems it could be simpler.. another option would be a simple electric inline oil pump that keeps the oil flowing until temps get down... Seems this could be simpler (?) (I am considering the turbo - in fact doing just like "Red1" throughout)

[John Monnett]

Seams like a good idea to fan cool the turbo until you look at the data. By the time a fan could cool down the turbo heat soaking would raise the temp in the bearing block above acceptable levels. An independent oil pump would circulate already hot oil from an already hot engine (that heat soaks after shutdown and remains hot for an extended time) not producing acceptable results in the turbo. Either synthetic oil (to withstand the high turbo temp) or a more efficient system has to be employed.

[n307tw]

Thank you Mark and John for further addressing the problem and this release of data backs up your position that this is something that the factory cares about and is working to fix. The data is impressive and the fact it has taken five different setups with different data points for us to see shows a real effort is being put forward. I also am anxious to see the results of the temperatures when Red-One is back in the air. I like the set it and forget it feature with the timer. I am sure there will be skeptics but at least you Wisconsin guys are taking the time to figure it out rather than throwing your hands up and saying oh well.

Mark or John have you experimented with Royal Purple HPS products? It has very high zinc and phosphorus content for the flat tappet engines like the Aerovee and is full synthetic but has additives to work with multiple fuels (not sure about lead though). It's more expensive but may be a full synthetic alternative to help with Turbo temps and corrosion as well, it may very well be worth looking into.

Royal Purple Website:
http://www.royalpurpleconsumer.com/products/hps-motor-oil/
Amazon Link to buy it:
https://www.amazon.com/Royal-Purple-36250-6PK-Synthetic-Technology/dp/B00ELHT3QK/ref=pd_sbs_263_2?_encoding=UTF8&pd_rd_i=B00ELHT3QK&pd_rd_r=X1DA1307377QDN62A4QR&pd_rd_w=It3jC&pd_rd_wg=dNlOR&psc=1&refRID=X1DA1307377QDN62A4QR

[Spinnetti]

Seams like a good idea to fan cool the turbo until you look at the data. By the time a fan could cool down the turbo heat soaking would raise the temp in the bearing block above acceptable levels. An independent oil pump would circulate already hot oil from an already hot engine (that heat soaks after shutdown and remains hot for an extended time) not producing acceptable results in the turbo. Either synthetic oil (to withstand the high turbo temp) or a more efficient system has to be employed.

Thanks John. What's the magic button in cars? I've got turbo cars and heavily modify and drive them hard and they don't run any pump after shutdown. Are they just surviving on good oil? (I typically use Castrol Syntec). They would get the same heat rise after shutdown I would think. My last big Garrett turbo on my Audi lasted about 110,000 miles at 28psi peak boost before it died (exhaust housing cracked and eroded mostly rather than coking up). If so, seems like most of the solution will be good synthetic oil and mogas with the cooling system as extra insurance?