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Overhauled Engine Math


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At some point in the future, I'm sure that I'll need a new-to-me or overhauled engine.  In looking on line at Air Power and others, I see that there is a $17k credit for returning the old engine.
If a factory overhauled engine is about $45k and if I could find/buy two more IO360 AIA engines on birds that haven't flown in 10 years and won't fly again, wouldn't it be nice to buy those for (say) $1,000 each, ship those back and get a new-to-me engine for a net $0 cost.

Dave windfield.farm

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One important thing at the middle of the unknown engine block….

The crankshaft… it is a very expensive piece of metal…

When sending the engine in for OH… the pricing will probably depend on a few measurements regarding the reusability of the crank…

PP thoughts only, not a mechanic…

Best regards,

-a-

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On 7/3/2021 at 6:54 AM, 211º said:

At some point in the future, I'm sure that I'll need a new-to-me or overhauled engine.  In looking on line at Air Power and others, I see that there is a $17k credit for returning the old engine.
If a factory overhauled engine is about $45k and if I could find/buy two more IO360 AIA engines on birds that haven't flown in 10 years and won't fly again, wouldn't it be nice to buy those for (say) $1,000 each, ship those back and get a new-to-me engine for a net $0 cost.

Dave windfield.farm

They are very specific in what they'll take as a core.

https://www.lycoming.com/sites/default/files/Lycoming Engines Exchange Engine Core Policy.pdf

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On 7/3/2021 at 6:04 PM, N201MKTurbo said:

Have you looked at price of a new IO-360? They are like 98AMUs

Do you have a link or reference?

I brought that up at breakfast and everyone threw the BS flag, but I suspect your correct. With a new 172 being a half mil, why wouldn’t 20% of that cost be engine?

I can tell you that for a crop duster that the engine cost is 40% and that’s OEM cost, which is way less than you or I would pay.

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1 hour ago, A64Pilot said:

Do you have a link or reference?

I brought that up at breakfast and everyone threw the BS flag, but I suspect your correct. With a new 172 being a half mil, why wouldn’t 20% of that cost be engine?

I can tell you that for a crop duster that the engine cost is 40% and that’s OEM cost, which is way less than you or I would pay.

https://www.airpowerinc.com/productcart/pc/TLEngineDetail.asp?catID=33&prodID=9064

 

Look at the list price. The actual price is quite a bit lower.

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1 hour ago, N201MKTurbo said:

https://www.airpowerinc.com/productcart/pc/TLEngineDetail.asp?catID=33&prodID=9064

 

Look at the list price. The actual price is quite a bit lower.

Seems a little suspicious, though, as I thought Lycoming stopped shipping anything with dual mags, either new or rebuilt/overhauled?

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My DIY engine rebuild is running just fine. It is still running hot. I wish it wasn’t. I have told a few here that they just have to wait until it gets broken in. It runs cooler on every flight. On this mornings flight cylinder 1 never got over 400 in cruise. That’s better than 435 in cruise. 
 

On the up side, it runs smooth as silk, and if I give it full power, it is a beast! Some day it will break in enough that I can run it at full power at cruise. So far it hasn’t  used one molecule of oil. 
 

I have high hopes for it.

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On 7/11/2021 at 4:04 PM, N201MKTurbo said:

My DIY engine rebuild is running just fine. It is still running hot. I wish it wasn’t. I have told a few here that they just have to wait until it gets broken in. It runs cooler on every flight. On this mornings flight cylinder 1 never got over 400 in cruise. That’s better than 435 in cruise. 
 

On the up side, it runs smooth as silk, and if I give it full power, it is a beast! Some day it will break in enough that I can run it at full power at cruise. So far it hasn’t  used one molecule of oil. 
 

I have high hopes for it.

Rich,

This is interesting data point for me.

I have only 2h on my rebuilt engine (single flight) and CHT seem to never reached 400F. During the second hour my max CHT3 was 355. This was at 75-80% power, at 6-7 deg C warmer that standard day at 2600' as displayed on my engine monitor and fairly rich (12-13.5 gph). I'll have to download data from the monitor . Also, Lycoming test run the engine in the test cell (1h?). I always read about engines running hot after OH but mine just didn't.

Not sure what to think about this...

 

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4 minutes ago, Igor_U said:

Rich,

This is interesting data point for me.

I have only 2h on my rebuilt engine (single flight) and CHT seem to never reached 400F. During the second hour my max CHT3 was 355. This was at 75-80% power, at 6-7 deg C warmer that standard day at 2600' as displayed on my engine monitor and fairly rich (12-13.5 gph). I'll have to download data from the monitor . Also, Lycoming test run the engine in the test cell (1h?). I always read about engines running hot after OH but mine just didn't.

Not sure what to think about this...

 

Feel lucky. I'm not sure exactly what is causing it. Tight rings, tight bearings? I miked all the bearings and they were right on spec. I bought cylinder assemblies and assumed the rings were fitted properly, maybe they are a bit on the tight side. Not much to do about it except fly it until it settles down. The baffling is all new and fits well.  

The first engine I did was about 25 years ago. It ran hot for the first 10 hours or so and then settled into a fine engine. I hope this one does the same.

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On 7/11/2021 at 7:04 PM, N201MKTurbo said:

My DIY engine rebuild is running just fine. It is still running hot. I wish it wasn’t. I have told a few here that they just have to wait until it gets broken in. It runs cooler on every flight. On this mornings flight cylinder 1 never got over 400 in cruise. That’s better than 435 in cruise. 
 

On the up side, it runs smooth as silk, and if I give it full power, it is a beast! Some day it will break in enough that I can run it at full power at cruise. So far it hasn’t  used one molecule of oil. 
 

I have high hopes for it.

There are all kinds of statements from lycoming about one running hot during breakin.

Thsts not been my limited experience though, what’s your GPH on takeoff?

Sometimes rings have to be fitted by filing, my last ones didn’t, New Millennium cylinders and pistons on a 540.

That motor I could and did run at full throttle for break-in, but it was a 235 HP 540, so full throttle was only 2400 RPM and not really stressing anything either, not like an angle valve motor.

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Just now, A64Pilot said:

There are all kinds of statements from lycoming about one running hot during breakin

Thsts not been my limited experience though, what’s your GPH on takeoff?

Not sure, my FF hasn't worked since the overhaul, I've been spending all my spare time on the 172, so I haven't got it working yet. trouble shot it down to the flowscan. I need to get a new one. That might explain the takeoff and climb numbers, but the cruise numbers are not affected by that. I fly LOP and limit the temps by TIT. right now I can get up to 1475 without the cylinders getting too hot. When I can get to 1550 I'll be happy. Even at that power setting, it is still doing a respectable TAS.

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I had forgotten you were a turbo, for a NA motor on break-in flights I stay full rich and down low, well below 5,000 to keep the power up high, so doing that full rich fuel flow matters. I don’t have turbo experience

A couple hours of that and they are broken in, meaning oil consumption has stabilized, usually to about 1 gt in 10 hours.

‘My current motor which is a 400 hour Gann overhaul I believe is burning less than 1 gt in 10.

I think I would run it rich and as high power as I could and not exceed 400 myself, and decreasing power for a while to let it cool, and go again?

Is the oil temp normal or is it high too? High oil temp could come from tight clearances 

 

Edited by A64Pilot
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