Hello all! I've identified a C206 in need of some TLC, but it is priced reasonable. It has all the main line items that I am look for except it has a turbo in it. What's involved in removing the turbo and having a normally aspirated engine? Is it worth the expense? Is an approval likely from the FAA?

Turbo costs weight, more frequent exhaust work, and lower TBOs, but I’d keep it anyway. You’d be hard pressed to recover your cost of conversion in maintenance savings.

You’ll love the climbs to high cruise altitudes, and being able to achieve high TAS when you get up there. Best STOL kit there is at higher altitudes is a turbo. You sacrifice no power loss to the altitude, the DA affects your wing, but not your power.

Keep the turbo. Good luck on making a deal. Hope the airplane is what you think it is.

Thanks Pinecone! Your assessment makes sense

I know of a company that removed the turbo from a T207.
They hassled with the faa for quite a while and finally ended up with a 1 time STC for the aircraft n number.
It all depends on your PIA tolerance level

Years ago, when approvals were relatively easy, an air taxi in Kodiak got a “good deal” on a Turbo 206 on floats. Ran it to tbo, which didn’t take long at all , then converted it to normally aspirated.

Owner said later that he should have paid twice as much for a normally aspirated 206, and he’d still have been money ahead.

I’d either keep the turbo, or move on.

One of the big hits the turbo induces is really high fuel flows, unless you spend a lot of time high. And then there’s maintenance….

MTV

I just explored this idea for a customer last year. My very best advice is don't waste your time. The FAA isn't going to be very receptive. Cessna isn't going to be very receptive. I'm sure it's possible, but unless you're just looking for a long drawn out project, I'd look the other way.
John

If you’re flying it on wheels I’d keep the turbo. Fly it at normally aspirated power settings when you’re not in a hurry for engine longevity.

Turbo engines can last a long time if you don’t run them hard all the time. The other argument is why have it if you’re not going to use it.

I see turbo 550’s on Cirrus’s making TBO if the engine is ran at in cruise 75% power or less and CHT’s limited to 380 or so.

The guys who cruise at 85% power and use 420 as a CHT limit typically pour $35k into the engine mid life.

Had to add my opinion and we all now about those-Mike. After complete rebuild of 81 T210N in late 90s flew our baby for 22 yrs. Sometimes 85% power and sometime just sight seeing over the Rockies. Started LOP in early 2000 and never looked back. At normal cruise 12,000 (no O2)- burn 14.5-15 gph, cht 350-360, true 160+ kts. When going straight over mountains from Denver:16-17K ft & O2- ROP due to bootstrapping= 19+ gph, cht 360-370, true 175+ kts- high alt usually temporary unless eastbound and back down when past the high Rockies. When coming home from skydiving in the midwest: 500 agl to avoid big head winds- LOP again and make it non stop from Quincy, IL to Denver with 1 1/2+ hours to spare.

Topped in 2000 as cyls were all heavily corroded and hole in exhaust valve from sitting before we bought project.

When I sold earlier in summer; 200+ past TBO= running very well, very good Blackstone oil reports and comps 68-75. Turbo was never off after TOP in 2000. Instead of 5 minute cool down before shutdown I adhered to taxi in and shut down immediately as the coolest your CHTs will be is after low power taxi; then they start warming up again. Watched engine monitor religiously.

We all have different experiences; I loved the turbo. LOP economical or power when needed. Wished I had one on my new 1956 182.

Jack

Good intel, Jack. I guess my point should have been "unless you're really careful with how you run a turbo charged 520" etc..... .

Unfortunately, many if not most pilots want to saddle up, fire up and go.....and don't want to carefully monitor their engine.

I rand an IO-550 LOP for 1200 hours, never a problem. Plane was borrowed for a week, pilot ran it high power and LOP (which is specifically prohibited by the manufacturer), engine needed five new cylinders. Same plane, essentially same mission......After new cylinders, ran it past TBO, and engine was clean as could be.

So, yes, turbo charged engines can be run to TBO with little maintenance. BUT, that has to be done with knowledge and care.

Not always applied by every pilot.

MTV

Thank you all for the info. Sounds like it should be left on the plane or I should find a different bird without one. Thanks again!

Isn’t more cylinder coolant (the blue stuff) on the rich side the secret to the longevity of a TSIO520? That and idling long enough for the turbo to spool down…


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How much low power did you flew with floats MTV? I'll try to go 70% after going LOP, but no more. Was ending with 50% after BMP but it won't hold altitude/speed with such a drag from my floats.

I had wondered a lot about investigating a turbo removal, but it seems swapping to a 550 is the only reasonable thing to do.

Canalguna wrote:How much low power did you flew with floats MTV? I'll try to go 70% after going LOP, but no more. Was ending with 50% after BMP but it won't hold altitude/speed with such a drag from my floats.

I had wondered a lot about investigating a turbo removal, but it seems swapping to a 550 is the only reasonable thing to do.

I ran the IO 550 on the 206 at pretty low power settings. LOP burning 13.2 or so gph. This was on the VERY large Wip 4000 straight floats. And operating generally from landing sites that were lower than 1000 msl. At temps, however ranging as high as 100 F. I regularly climbed over 5 to 6000 ft mtn range enroute.

I’ve forgotten specifics, but that engine had a hard upper percent power, above which NO leaning was permitted. That was the risk letting a pilot who was routinely flying an IO-520 fly the 550, without strict and stern lectures on leaning. I think the upper limit was 70% power….. So, the IO 520 guy gets in the 550 airplane, and cruises at 25 square….a pretty common setting for 520. But, that pier setting in the 550 is….like..80 some % power. So 520 guy leans it down to 16 gph, which is what he’s used to, and promptly smokes a bunch of cylinders.

The point is, the 550 is a continuous rated 300 hp, where 520 is 285 continuous rated. Max rpm on 550 is 2700, on 520 it’s 2850, to get that 5 minute 300 hp rating. But, most 520s never make 300, due to the way the engine was certified.

Very different engines, and need some knowledge to operate. But, the 550 is magic…a 300 hp engine that actually makes 310. And that engine, operated intelligently, loves LOP.

MTV

Interesting info and stories Mtv. I am not planning to get higher than 70% in LOP anyway, and my engine is the tsio520m. Anyway it seems that a just a bit of mishandling with this turbo engines will get you making a top overhaul pretty fast. I can only dream about changing to a 550 for now (and Aerocets)