What is this engine part?

[Mcstealth]

 Twin turbo? What's is that in the middle?

[carusoam]

David,

What plane/engine is it attached to?

This will give us a hint to who to invite to the conversation…

Best regards,

-a-

[Mcstealth]

3 hours ago, carusoam said:

David,

What plane/engine is it attached to?

This will give us a hint to who to invite to the conversation…

Best regards,

-a-

Mooney at Dugosh. It has 262 embossed into the upholstery. 

[Greg Ellis]

If what you mean by the middle part is what I have circled in red then that looks like the center housing with the oil inlet and outlet to lubricate the turbo shaft.

[A64Pilot]

On 4/7/2022 at 1:33 PM, Greg Ellis said:

If what you mean by the middle part is what I have circled in red then that looks like the center housing with the oil inlet and outlet to lubricate the turbo shaft.

yep, with the turbine to the left, and the compressor on the right, normal single turbo

[1964-M20E]

left side is the part where the hot exhaust gases go to get de-compressed, right side is where the cool clean air goes to get compressed (becomes hot air)and the middle gets the slippery stuff that keeps everything turning.

[A64Pilot]

I meant to point out just how close the center section is to the hot side of the turbo, a two minute idle prior to shut down will probably save you some grief later, if it doesn’t it’s only two minutes and most of us take longer than that putting away maps, headsets etc anyway.

Issue is after shutdown if you don’t the hot side could be hot enough to burn off the oil, which turns to carbon, that eats up the center section bearing, this causes excessive oil consumption and maybe contact of the compressor to the housing, trashing both of them. bunch o money.

It’s not so much a pressure driven thing as a heat driven thing, a turbo makes use of what is normally waste heat and can be a more efficient engine

Edited April 12, 2022 by A64Pilot

[carusoam]

7 minutes ago, A64Pilot said:

I meant to point out just how close the center section is to the hot side of the turbo, a two minute idle prior to shut down will probably save you some grief later.

Issue is after shutdown if you don’t the hot side could be hot enough to burn off the oil, which turns to carbon, that eats up the center section bearing, this causes excessive oil consumption and maybe contact of the compressor to the housing, trashing both of them. bunch o money

Sounds right, but not quite…

There is sooo much oil (coolant) running through there…

The TC’d Mooniacs know that the turbo is at its coolest at touch down…

With a known increase in temp after taxi…

There is a qualified reference for this as well…. Probably from the Deakin camp… (?)

OWTs for turbo ops…  

PP stuff I have read around here…

Best regards,

-a-

[Greg Ellis]

11 hours ago, carusoam said:

Sounds right, but not quite…

There is sooo much oil (coolant) running through there…

The TC’d Mooniacs know that the turbo is at its coolest at touch down…

With a known increase in temp after taxi…

There is a qualified reference for this as well…. Probably from the Deakin camp… (?)

OWTs for turbo ops…  

PP stuff I have read around here…

Best regards,

-a-

John Deakin discusses this in his Pelican Perch Articles.  It is actually #36 (really #31-36) and he states that the turbo is it's coolest right before touchdown and then proceeds to heat up again on the ground and when idling.  He states that the best thing for it is to shut it down and then open up the cowling to allow heat to escape that way.  By running it in idle it just gets hotter.  I think the engine guys at Advanced Pilot Seminars in Ada Oklahoma also showed this using their engine stand or something to that effect.

[A64Pilot]

EGT / TIT may be coolest on short final due to the engine not being under load, but I doubt that large oil cooled chunk of iron has cooled yet, it’s oil cooled and that takes time. Unless there is a thermocouple measuring center section temp which I’ve not seen, I’m going to be skeptical that the center section actually heats up during idle after landing, or cools that quickly. EGT sure, but not the center section. No other turbo works like that

On edit, what is in the POH, and or what does the engine manufacturer say?

Edited April 12, 2022 by A64Pilot

[Fly Boomer]

12 minutes ago, A64Pilot said:

Unless there is a thermocouple

Not sure about thermocouple, but George Braley of APS fame, said they had instrumented an airplane (probably Bonanza) to measure the results that Anthony mentioned above.

[A64Pilot]

The guys who build the turbo disagree, but really what matters is what does the POH say, if it doesn’t say anything, then my intepretation is you can do whatever you want, but if it has a cool down procedure, then you should follow it.

 

Edited April 12, 2022 by A64Pilot

[A64Pilot]

Why don’t my Youtube posts embed?

[carusoam]

2 hours ago, A64Pilot said:

Why don’t my Youtube posts embed?

Seems fine this afternoon…

-a-

[carusoam]

For A64…

Using the POH is the way to go… until the fine print isn’t fine enough…

What Deakin did… was combine the information to separate what people thought was going on, and added instrumentation to show what is actually going on…

In most cases turbo cooling is done on X-country flights during descent and landing…

If the POH has only one shut-down procedure… it is going to cover worst case scenarios… like multiple traffic pattern ops…

Where one procedure fits all…

oddly, turbo cooling is best done using the unique procedure of cooling during descent and landing…

As apposed to a specific cooling step that isn’t as good… but works adequately enough…

 

What we have learned over the years… when it comes to engine operations… the POHs have left out some known details that were written by the engine manufacturers… and handed to the plane manufacturers… where some details got lost on the editing room floor…

-a-

This is taken from the pelican’s pearch article offered in a post above…
 

Cooldown/Shutdown

I would guess that when you see (and hear!) someone running their engine in the parking spot after landing “to cool the turbo,” you are almost always seeing someone who is getting it hotter than it was when he arrived at the spot. If you don’t make the high-drag approaches, and you lean brutally after landing, that turbo will be just about as cold as it will ever get, short of a shutdown. On the other hand, if you’ve made a long, high-drag approach with high power, or you’re one of those dreadful types who taxi with cruise power while dragging the brakes to keep the speed down, or you have a long, sharply uphill taxi to the ramp, you may need the cool down. A tip that might do your engine more good is to hop right out after shutdown, and pop the cowling open (or even just the oil access door) if you can. That will let a LOT of heat out of the accessory section, avoiding “cooking” the components, hoses, and seals there. But even that little tip is probably completely unnecessary if there is more than 3-5 knots of wind blowing in the general direction of either the front or the back (cowl flaps open, please) of the engine.

George Braly again:

We know of one operator of a turbo twin Cessna. He owned the aircraft for 15 years before the issue of “turbo cool down” ever showed up in the aviation literature. Through three full TBO runs, with almost no premature engine or turbo problems, this operator would routinely land at his uncontrolled airport, turn off at mid-field, taxi about 100 yards, and immediately shut down both engines. The aircraft was then promptly pushed into a T-hangar, where it could not benefit from any natural wind for a further cool down. These would have been ideal conditions to promote problems with turbochargers not being properly allowed to cool down, if there was any truth to this OWT. This operator, in more than 8000 engine hours, never experienced any problems with the issue of “coking” a bearing on a turbocharger.

Finally, here’s a graph of the type of descent I’ve just described.

Click for a high-resolution version.

The chart begins at 11:49:21 PDT, on 10/02/2000, at 10,500 feet. Note that TIT and EGT is read against the left side numbers, while all other parameters are read against the right side. For the first five minutes, I pre-cool the CHTs by beginning a gentle descent, and reducing RPM and fuel flow on the lean side. That CHT drop too fast for you? Fine, you have complete control over how fast you drop the CHTs, take all the time you want.

At about 11:55:00, I simply pulled the throttle back, and dropped the MP from 31.0″ to 18.0″. In order to demonstrate where the mixture ended up to a passenger, I fiddled with it a bit, and added just a bit of fuel. In fact, it would probably have been better if I’d just left it alone (as I usually do) because that extra tweak actually caused the CHTs and EGTs to RISE! Uhh, what WERE you saying about “shock cooling”? We have just pulled off 12 full inches of MP in one swell foop, and all engine temps go UP! The reason is, of course, we have gone from very LOP (and relatively cool CHTs) at a very high power setting, to just ROP at a very low setting. The linkages in my engine are “just right” for this purpose, yours may vary, but at worst, you’ll need to fiddle with the mixture once, to get it just ROP, or wherever you want it.

For the next 10 minutes on the chart, we descend at about 1,000 fpm, at about 140 knots, gear up. If I’d wanted more descent, all I had to do was run the IAS up to the bottom of the yellow arc, or put the gear down, or even pull off more MP. For a couple minutes in the pattern, the CHTs dropped very gently and then they rise a bit while taxiing in. At shutdown, they begin a long, slow cooling process.

Well, we’ve gone from startup to shutdown, with a “flight time” of five months! I hope I’ve not led you too far astray, and above all, I hope I’ve made you think.

I think I’ll take a break from engines, for a while!

Be careful up there!

[Mcstealth]

On 4/12/2022 at 12:01 PM, A64Pilot said:

EGT / TIT may be coolest on short final due to the engine not being under load, but I doubt that large oil cooled chunk of iron has cooled yet, it’s oil cooled and that takes time. Unless there is a thermocouple measuring center section temp which I’ve not seen, I’m going to be skeptical that the center section actually heats up during idle after landing, or cools that quickly. EGT sure, but not the center section. No other turbo works like that

On edit, what is in the POH, and or what does the engine manufacturer say?

Uh oh. Here we go.

ROP LOP  Bladders reseal.........hehehe

Edited April 14, 2022 by Mcstealth

[A64Pilot]

Carusoam

 The article you referenced shows EGT / TIT, and lots of irrelevant data like fuel flow and CHT, but none of that data is relevant.

It does not show turbo center section temp, and is therefore not worth much, the only relevant number, center section temp, is missing, and it’s incredibly easy to get, a simple thermocouple connected to the center section and a multi-meter and you have relevant data, but that wasn’t done. Why?

Why do you think Hartzell went through all the trouble to make that Video? I can tell you why, it’s because of people like you linked to getting people to not follow the manufactures instructions nor the POH. Why else would Hartzell bother?  They did it to prevent premature Turbo failures is why

I’m glad he’s not destroyed a turbo, but that doesn’t mean he has a working system anymore than the guys I know that regularly slip a Cessna with flaps.

Sure if you come out of the flight levels at low power and never go back to cruise power, then sure the center section is probably cool, but notice in the video Hartzell points out that if you go above 1200 RPM even for a short time, the clock resets. 1200 RPM is very low power, not nearly enough to maintain flight 

So how many people actually shoot the entire approach and landing at very low power, never increasing it? Power lower than a 1200 RPM idle.

What is it with people who think the engine manufactures are fools and their favorite internet social influencer is the one with the real knowledge? 

Every Farmer, OTR Truck driver etc knows to idle to cool the turbo, more modern cars don’t need it because their center sections are water cooled and never get hot enough to need it, but aircraft are not of course.

Oh, LOP EGT is usually higher than ROP EGT, so running LOP isn’t helping to cool the turbo

Edited April 15, 2022 by A64Pilot

[carusoam]

20 minutes ago, A64Pilot said:

it’s because of people like you linked to getting people to not follow the manufactures instructions nor the POH.

I almost feel insulted… 

But, I know my writing skills are still getting practiced…

I’m guessing you didn’t understand what I wrote… (most likely my fault…)

So….

Let’s clean things up a bit….
 

You might want to read what I wrote this time…

1) Follow the POH….

2) Find the engine manufacturers guide for the engine…

3) Find the logic that explains this in layman’s terms…

 

And… for following my guidance…

Know that I’m only a private pilot trying to link people to various sources of information and other resources…

I’m not a mechanic or engine builder…

 

But, I do like your idea of adding a turbo temperature probe…

Why isn’t that normal for people that have a JPI900 or so?

 

Something is missing, and can be done better…

Or should I just toe the aged company line with no further detail?

 

Best regards,

-a-

 

[A64Pilot]

I don’t mean to insult, but by now you know that I simply lack social graces.

Put it this way, you can’t go wrong following the POH, if there is an accident of any kind and you were following the POH you’ll come out OK, if you weren’t then it might be tough explaining to the FAA and your insurance company why not. There is really other than an Emergency no justification for deviating from the POH

If you have a Turbo failure and follow the POH, then you have a much better chance at Warranty than if you admit that you didn’t,that you were following some internet advice instead.

Turbo center section temp isn’t usually monitored because if you follow POH procedures it’s not necessary, but if I ran a Turbo I think I would temporarily install one just to gather data, to satisfy my curiosity. I’d also likely install overheat sensors permanently as it’s my understanding that exhaust system failure on turbo aircraft isn’t unknown, and I’m sure I could get a field approval as something that doesn’t interfere with any system but improves safety is usually easy to gain approval, AOA sensors as an example. There is a AC covering that but it been a long time since I’ve seen it, but it streamlines approval.

I’m actually surprised there is no STC for one, seems it would sell?

Then lastly Joe Brown who owns Hartzell is no fool, I know him well, if there was a better procedure I’m certain he would have his Engineers investigate it, in fact I’d bet lunch they already have and that might be why the Video was made. Joe has been very successful in Aviation at a time when most are losing their pants. He’s also a very Ethical business man, where most aren’t.

He flies around in a TBM by he way, or used to anyway so he can’t be all bad. Don’t remember the N number but the last two are HP of course.

Edited April 15, 2022 by A64Pilot

[carusoam]

2 hours ago, A64Pilot said:

I don’t mean to insult, but by now you know that I simply lack social graces.

Some time you may recognize…

Not everyone here is as skillful as you are…

Some people make mistakes… and it is OK.

 

The objective of MS… is to keep everyone involved… get everyone up to their next level… comfortably… casually…

Soooo many people start out looking for guidance on basic things…

New to aviation, new to plane ownership, new to Mooneys, new to being on MS….

Looking for guidance on… engines, props, alternators, AC compressors, voltage regulators, or what does this switch do?  How to fly, how to fly a Mooney, how to fly a turbo’d Mooney… how to go LOP in their 252 in the flight levels…

 

We kinda want to keep from accidentally driving people away with petty spats… my plane is faster than yours…. Because I have more money than you… or I spent decades in the air force and you didn’t…

Each time we drive somebody away… they miss a discussion like what DA is in the summer…. Or how to do the T/O calcs in an easy way…

By not taking the time to be nice… there will be a dozen new MSers that will be afraid to ask a simple question that may save their life…

 

Fear not…

I have a writing handicap…

People usually send me a private message when I make mistakes…

Take a look at my post count… just based on numbers… there may be a mistake in there somewhere… every day…

If I say something incorrect or incorrectly… I want to know….  I can learn from it, and fix it….

When you put me in a category with other people…. “People like you” you will quickly realize… there are not a lot of people like me…. I have met a few though… here on MS.

Try to be nice to everyone… you never know who is going to be able to help up you out when you need a hand… oddly, I have received plenty of help from MSers over the years…

There isn’t a special prize for being the most ignored MSer…

 

The worst part… you have good input… every day… 

When you write in an abrasive way… people click the ignore button on you… all that writing, falling on deaf ears… kinda defeats the purpose…

Write friendly!

It is worth it…

Best regards,

-a-

[carusoam]

My only run in with Joe Brown of Hartzell…

A decade ago…

I had to buy a new prop for my plane…

The spinner came in the wrong dimension…

They didn’t have the right dimension to match the Mooney cowling…

Hartzell told me they would let me know when the right one was available…

I can hardly wait to find out if that will be covered under warranty or not…

Mooneys are all about aerodynamic efficiency… from nose to tail…

Mine starts out with a 90° step right on the nose… about 1/4”…

It’s lovingly referred to as the Hartzell step…

 

Soooo…..

If you know Joe Brown…

Casually ask him if they ever got a spinner about a 1/2” larger in diameter for the Long Body Mooney’s…

Its a bit annoying at pre-flight time… it doesn’t look right… it’s not aerodynamic…

It looks like a sag, but up close everything is nicely aligned… 

 

My contact at Hartzell was Mike Trudeau… 

Project was about a decade ago…

The words “built on honor” make me want to finish this project…
 

Best regards,

-a-

[Yetti]

there are strap on thermocouplers.  the Dynon EMS has extra inputs for extra thermocouplers.   I hooked one up and left it behind the panel to see what the heat is.   you could put it on the side of the big chunk of turbo metal.   I would see it like this.   Lots of airflow through the low pressure part of the cowl while flying.  Not so much when on the ground.   Even my non turbo F POH says to do things if you stay on the ground after run up.  

[Fly Boomer]

16 hours ago, A64Pilot said:

LOP EGT is usually higher than ROP EGT

Can you elaborate on this?  I would expect more burning fuel in the exhaust (ROP) to be hotter than less (or zero) burning fuel in the exhaust (LOP).

[Hank]

1 hour ago, Fly Boomer said:

Can you elaborate on this?  I would expect more burning fuel in the exhaust (ROP) to be hotter than less (or zero) burning fuel in the exhaust (LOP).

Most people seem to fly 10-25 LOP, versus 50-100 ROP. So LOP is 25-90° warmer.

[A64Pilot]

2 hours ago, Fly Boomer said:

Can you elaborate on this?  I would expect more burning fuel in the exhaust (ROP) to be hotter than less (or zero) burning fuel in the exhaust (LOP).

Hank got it, temp is temp.

Way back in the late 70’s I used to build and drag race turbo bikes. One trick I learned was to dial in a lot of valve overlap, we could do that easily as motor was twin cam and we adjusted cam timing by slotting the chain sprockets that drove the cams. This caused fuel and air to be blown into the exhaust and at first glance would seem to waste boost, but fuel burning in the exhaust system, plus the engine was a lot more burning fuel, which made the turbo spool up much faster.

It literally fried the chrome on the exhaust, burning fuel in an exhaust isn’t normal, at night I swear you could almost see through the headers.

 Prior to that I experimented with Nitrous oxide that would be turned off with a pressure switch once boost built.

As you can imagine cool down on a turbo drag bike wasn’t happening so we ran a special pure synthetic oil, at the world finals in Mississippi we broke a chain and that broke the case dumping the special oil, so I built the motor that night and not having anything else used Castrol 20w-50, well guess what? the Castrol showed less wear on the center section bearing, I’d take apart the turbo after each race weekend and replace the bearing, which was easy and cheap, but once the bearing wore, then the compressor would make contact with its housing, trashing both. We ran almost zero clearance between the two, clearance was adjusted by shim washers under the compressor wheel

https://www.dragbike.com/star-racing-george-and-jackie-bryce-build-a-small-motorcycle-speed-shop-into-a-drag-racing-institution/

It was Star Cycle back then and our expertise was in building Kawasaki Z1 turbo bikes, I was there 79 and 80.

Point of this is to try to say I like turbo’s and have a little experience with them

Edited April 15, 2022 by A64Pilot