Care and feeding of Turbos

Let'sgoflying!

Let'sgoflying!

Touchdown! Greaser!
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Dave Taylor
Might get something with turbos. I've never operated one.
Cont TSIO-550
turbo-normalized; I presume an automatic wastegate

I keep hearing people (interestingly its people who do not own a turbo) that the cylinder life will be 500hrs; ie $15K every 5 years and then turbo overhaul and repair well before engine tbo.

Why don't we skip the stories, theories, rumors - and focus on the title?

What are some simple operational and maintenance guidelines for prolonging cylinder and turbo life? Assume there is interest in LOP ops.
 
I'm all ears to this.

Mine has required some tending....that would require extra shop time. I can't really quantify, since I did the work.

There are extra oil lines, waste gate maintenance, controller adjustment....

I'd think more of the issue is finding a mechanic who knows the systems....and you're not paying for his training in shop time.
 
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I have a little experience in turbo charged engines.

Basically:

Watch temperatures, Cylinder head and oil, don't run in the red lines, obviously.

Move the throttle(s) smoothly. Moving up to take off power quickly is Ok.

Plan descents long in advance. ATC on IFR flights will throw in some surprises.

Not yanking the throttle back to idle after being at cruise power. I do 3 inches, wait 3 minutes, (usually 5 if I planned the descent right) then one inch per thousand feet during descent.

If you have to do it yourself, don't over boost on takeoffs.

This is what I do, there will be others along with different advice that will be just as good.

What plane ya lookin' at..??

Oh yeah.... don't spray cold water in the turbo to cool it down......:lol::lol::lol:
 
Operate very smoothly and don't get it hot. Change oil lines every 8 or 10 years. Aeroshell 15-50 runs cooler than any pure Dino oil I've tried.

Did I mention operate smoooooothly? No ham fists on the throttle.

I should mention that smooth operation prolly has as much to do with internal engine balancers. The TSIO-360 is a bit finicky.
 
Oh....and don't do a cool down for 5 min. On final thru taxi leave throttle at or near idle and shut it down with no cooling. TITs are cooler that way. Additional idling heats up the turbo. ;)
 
Checkout_my_Six said:
Oh....and don't do a cool down for 5 min. On final thru taxi leave throttle at or near idle and shut it down with no cooling. TITs are cooler that way. Additional idling heats up the turbo. ;)
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Purty important, bring it in cool and park it. Done.
 
I had one cylinder OH at 1000 hours with my turbocharged engine. The others were still going strong when I sold the plane.

The others hit the key points: break it in properly and drive gently. I targeted cruise power at 65%, no more than 70%. That kept temps comfortable. I did lean it out well, but kept an eye on the tit.

YMMV, but if you treat them well, there is no reason that it should be a big problem.
 
Tell me what is damaged when you are aggressive with throttle?
Does it overboost momentarily?

What are some MP and TIT goals?

And; LOP......
 
In the turbos I've flown the big issue with quick throttle on takeoff is being equally quick with the rudder as the turbo spools up. It's definitely fun the first time... more right rudder indeed.
 
Our fleet of 8 TSIO-520-M's usually run up to OH without any cylinder work. 125ROP, careful with takeoff power settings, and gradual power reductions when coming back in.
We (almost) redline them all the time on climbs (most of flying is at max gross and 100+++ heat, and 7000+ density altitude).
 
Let'sgoflying! said:
Liked your other points; will probably like this one once I understand it - thanks!
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Yeah, that was a little vague. On take off, I move the throttles up about a third until the governors catch up.... about 10 seconds at the most, then push the throttles up to max take off manifold pressure. Smoothly and steady and not really slow.

Don't forget the rudder.
 
Zeldman said:
I have a little experience in turbo charged engines.

Basically:

Watch temperatures, Cylinder head and oil, don't run in the red lines, obviously.

Move the throttle(s) smoothly. Moving up to take off power quickly is Ok.

Plan descents long in advance. ATC on IFR flights will throw in some surprises.

Not yanking the throttle back to idle after being at cruise power. I do 3 inches, wait 3 minutes, (usually 5 if I planned the descent right) then one inch per thousand feet during descent.

If you have to do it yourself, don't over boost on takeoffs.

This is what I do, there will be others along with different advice that will be just as good.

What plane ya lookin' at..??

Oh yeah.... don't spray cold water in the turbo to cool it down......:lol::lol::lol:
Click to expand...
I do all of this except 1 inch per minute when pulling back the power and 3 min. cool down before turning off the engine.
 
Let'sgoflying! said:
Tell me what is damaged when you are aggressive with throttle?
Does it overboost momentarily?

What are some MP and TIT goals?

And; LOP......
Click to expand...
On the TSIO-360 overboost is a possibility with its fixed wastegate and critical altitude in the low teens. I open the throttle enough to get the turbo working then inch it up from there. I target about 5 inches below max boost out here in the land of long runways. Short field? Max power.

Another aspect of the engine is the internal balancer(s). Supposedly their 'set' can be knocked off by rapid throttle movement. I just make it a point to be smooth with the throttle.

Max tit is 1650 and I run it at least 100 degrees below that in cruise for the most part. The gamis really helped with tit management since it will run lop now.
 
Scott@KTYR said:
I do all of this except 1 inch per minute when pulling back the power and 3 min. cool down before turning off the engine.
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I forgot about the time before shut down. If I taxi for more than 3 minutes, I will shut down right after I finish my paper work. And 1 inch per minute is about a 1000 fpm descent for me, so that is why I use the 1 inch per thousand feet power reduction.
 
Just a comment on the 1"/min crowd. I believe folks do that to manage cylinder temperature and avoid rapid cooling resulting in cracked cylinders. An old AI described the things he has seen which resulted in cracked cylinders which the main one was pulling to idle to go down.

Running lop the cylinders are about 300 degrees or a bit more on the -360. Just keeping 20+ inches on for the descent keeps things warm enough that cracking isn't possible. Of course without an engine monitor folks couldn't keep an eye on things and the rules of thumb get used. The rules work and are easy to communicate. Using some slow engine power reduction schedule is fine, just not necessary when there is a monitor.
 
I owned a Turbo Viking for 3 years. So here is my real world experience.

When I bought the beastie she had compressions anywhere from 69-76, with a disconnected ambient line to the automatic waste gate. Not a single vaunted Bellanca mechanic caught the problem until I looked at the system and started at the beginning for airflow and worked my way from start to finish. Took 10 min. I asked my mechs for credits against future jobs - since before looking for leaks and spending a fortune of my money shouldn't step 1 be making sure its hooked up correctly? So - I had that prob out of the gate - but I fixed quickly.

Max TIT is 1650 as others have noted - thats metallurgy related. So I ran mine around 1550 or so. The motor liked it there - if I ran it LOP it liked it even move - even though I lost about 10 knots of speed. LOP I'd see CHT's around 340. As said, the motor loved it LOP.

After 2 annuals all my compressions were 74-76, the motor was running like a top. No burned valves, no rings, nothing.

As I tell people all the time, the motor does not know its not running at 3000'MSL when its at 27" of MAP. So why does it care that its normalized? It doesn't - the key to running a turbo is mixture control - you don't have to do anything to a motor as you descend because the turbo will keep the MP constant if you have an automatic wastegate.

I simply memorized four fuel flows - pattern alt for about 100 knots, this also worked for final approach speed, LOP at 27" and ROP at 27", and then descent at about 20".

I saw no unusual maintenance expense from the turbo after flying it 500 hours. . .
 
Explain the 'Turbos & LOP' thing to me?

So I've always reserved LOP (with my na IO-520 engine) to above 7500' where I was only making 65% hp and it was safe to do so.

With a TN engine, I will have sea level available (and thus, higher hp) up to the critical altitude.

So is LOP done by reducing MP/RPM until below 65-70%hp?

I thought the whole point of a turbo was to maintain hp, so that can't be the answer.

Fill in what I missed here.
 
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You and I are gonna go to Ada, Dave.
 
Let'sgoflying! said:
Explain the 'Turbos & LOP' thing to me?

So I've always reserved LOP (with my na IO-520 engine) to above 7500' where I was only making 65% hp and it was safe to do so.

With a TN engine, I will have sea level available (and thus, higher hp) up to the critical altitude.

So is LOP done by reducing MP/RPM until below 65-70%hp?

I thought the whole point of a turbo was to maintain hp, so that can't be the answer.

Fill in what I missed here.
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LOP while boosted is best done with the big mixture pull while watching fuel flow. Gotta do yer homework ahead of time to know what and where. Ya pull quickly from ROP to some preselected LOP point.

A turbo boosts engine efficiency. How that is used (best power, best fuel flow) is up to the operator. A GAMI test maps fuel flow and EGT so ya know what throttle settings produce in terms of airspeed, fuel flow, EGT and TIT. For the TSIO-360 in the 'Kota the POH lists fuel flow for ROP and Peak operation at various power settings and altitudes. The GAMI test extends that power setting table.

TL:DNR pull the TSIO-360 to 8 gph while at 30" and yer below 65% power and operating efficiently LOP.
 
So you are leaving the power up, probably beyond 75% and still able to LOP-it. Is what I think you are saying. Way lean of peak to stay out of the red box probably. And pulling fast, not lingering in detonation zone. Yes, schooling is likely in the future. ROP til then.
 
Let'sgoflying! said:
So you are leaving the power up, probably beyond 75% and still able to LOP-it. Is what I think you are saying. Way lean of peak to stay out of the red box probably. And pulling fast, not lingering in detonation zone. Yes, schooling is likely in the future. ROP til then.
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Yeah, I did a lot of reading before getting an engine monitor and experimenting with POH power settings. Then I ran the GAMI test. After installing injectors from GAMI the test is run again. At that point yer about ready to run LOP.

These days some engines are flow balanced and ready for LOP operation from the factory. The rest of us in the certified world have to jump through the hoops and go to GAMI for an STC'd solution.

The really sad thing is flow balancing is really ancient tech that was never embraced by aircraft engine manufacturers for Light aircraft. Cirrus uses an engine that supports LOP. I've heard some Lycoming engines are flow balanced. The TSIO-360 in the 'Kota was a mess - peak TIT was just a number and individual cylinders were ROP and LOP. It's no wonder many had to be topped half way to TBO.
 
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