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High CHT, 470 degrees +.


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8 minutes ago, carusoam said:

If CHT4 is the one that is only getting 220 ROP...

That would be interesting...

With the IO550... we lean in a range from 300° to 200°F... during the climb... (blue box EGT method)

If you leave the mixture in during the climb... the MP drops faster than the FF... EGTs are getting colder as you go higher...

When we drop out the bottom of the blue box, adjust the mixture to the top of the box again...

Best regards,

-a-

 

If only.  #4 is right at 300.  It has the second highest spread from rich to peak

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9 hours ago, ragedracer1977 said:

I agree.  Id consider taking it to Maxwell, but that's a 5 hour flight.  And in the current situation, I'm not sure I want to ride the germ tube back home

Please note, I suggested that it was time to go to the 'big gun' and then noted Maxwell (a big gun, but not the only one).

9 hours ago, chriscalandro said:

You want the guy to fly thousands of miles to work on one of the most generic widely used engines in the industry?

This, as you will discover at the end, is a Mooney problem, hence my suggestion that @ragedrarcer1977 get to a Mooney big gun. 

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I am not sure if you have done this but since you recently signed up for Savvy Analysis, they are probably going to request that you do their flight profile.  Have you done this?  It can be found in the help section of your Savvy Analysis Dashboard on the website.

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I am quite interested in this issue you are having because I currently am having a very similar issue although mine is with #3 cylinder in my 63 C model.  The engines are equivalent.  I have one cylinder that is crazy hot 17 hours into its break in from being overhauled (hotter than what should be expected during break in period).  It is currently back in the shop trying to trouble shoot the problem.  I will let you know what they find out.

They are currently looking at:

1: Baffling since it was all removed when the engine was removed to replace the engine mount

2: Intake/induction leak

3: Exhaust leak

4: Mags/timing

5: Remote possibility of a bad sensor

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6 hours ago, HRM said:

Please note, I suggested that it was time to go to the 'big gun' and then noted Maxwell (a big gun, but not the only one).

This, as you will discover at the end, is a Mooney problem, hence my suggestion that @ragedrarcer1977 get to a Mooney big gun. 

I think you’re wrong. This is an 0360 problem, not a Mooney problem. Hot running O360s are not uncommon. They seem to be more common in Mooneys but I think that’s likely due to the fact that Mooneys on the whole have been upgraded with more sophisticated engine monitors then other Airframes flying behind this engine.

I think these engines came with just barely adequate fuel flow from the factory.

Edited by Shadrach
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7 minutes ago, Shadrach said:

I think you’re wrong. This is an 0360 problem, not a Mooney problem. Hot running O360s are not uncommon. They seem to be more common in Mooneys but I think that’s likely due to the fact that Mooney is on the whole have been upgraded with more sophisticated engine monitors then other Airframes flying behind this engine.

I think these engines came with just barely adequate fuel flow from the factory.

We can agree to disagree. You're right in saying that these engines run hot, but they seem to run extra hot in Mooneys unless all the Mooney-specific parts (baffling, exhaust, etc.) are right.

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21 hours ago, carusoam said:


205S,


thoughts for a CO monitor will follow... :)

If you have one, did you get alerted about the exhaust leak?

Best regards,

-a-

I did not have one at the time so I did not get a CO alert. My JPI provided an alert for the high CHT so I only made one lap around the pattern and landed. However, you better believe that I have since purchased one!

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59 minutes ago, Shadrach said:

I think you’re wrong. This is an 0360 problem, not a Mooney problem. Hot running O360s are not uncommon. They seem to be more common in Mooneys but I think that’s likely due to the fact that Mooney is on the whole have been upgraded with more sophisticated engine monitors then other Airframes flying behind this engine.

I think these engines came with just barely adequate fuel flow from the factory.

A good friend of mine with a Comanche 180 has no issues with high CHT's on his Insight G2 after reworking the baffle sealing tapes.  It's the same basic engine as the C model Mooney.  I'm not sure about carburetor models but it does seem to be unique to the O-360, likely the carb jetting is too lean as both airframes have similar cowl designs.

Clarence

 

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A good friend of mine with a Comanche 180 has no issues with high CHT's on his Insight G2 after reworking the baffle sealing tapes.  It's the same basic engine as the C model Mooney.  I'm not sure about carburetor models but it does seem to be unique to the O-360, likely the carb jetting is too lean as both airframes have similar cowl designs.
Clarence
 


Indeed the carburetor is an issue. There are three different kind of carburetors. One of them is extra lean, that is the one that presents more issues. As I mentioned before you have to make sure that you have the right one.


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Full throttle gives a slight enrichment to the mixture due to the "economizer" function of the carburetor. Usually doesn't decrease temps much (if at all) due to higher power output = more heat.

Probably a dumb question- what airspeed do you climb at?  Our airplanes climb at a comparable feet per minute whether at 120-125 or at 100 mph.

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Just now, Andy95W said:

Full throttle gives a slight enrichment to the mixture due to the "economizer" function of the carburetor. Usually doesn't decrease temps much (if at all) due to higher power output = more heat.

Probably a dumb question- what airspeed do you climb at?  Our airplanes climb at a comparable feet per minute whether at 120-125 or at 100 mph.

120-125.  

Savvy seems to be suggesting not pulling back throttle, because that keeps it richer, instead just reducing RPM.

Could I put some aluminum tape over the baffle/cylinder gap seen in the photo below? I mean, I can, but is there any reason I shouldn't for a test to see if it helps?

 

20200407_121809.jpg

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+1 On improving cooling for the offending cylinder...

 

As Oscar pointed out...

Some things to consider about the Carburetor...

The M+S manual is posted around here, probably in the download section...  Marvell Schebler

There are different versions of the carb available... which are different set-ups...

One big variation is the size of the main fuel nozzle... it would be interesting to see which one you have... a serial number study is probably all it takes... going to a larger nozzle size will probably deliver more fuel...

There is a secondary fuel nozzle that opens up when the throttle is pushed beyond a limit...

With the JPI... you can probably watch the secondary nozzle open and close with the EGTs...

On the ground, you can verify the valve’s arm that operates the second nozzle... see if something is changing here...

 

In cruise flight... Most O360 pilots want to cruise WOT, but with the secondary jet closed... pulling the throttle back a small amount will do this...  Hank explains this operation often...

The secondary jet adds another 10% FF... 1-2 gph... (?)

With the FF... this should be pretty obvious as well as you dial the throttle out...

 

While checking things around the carburetor...

Verify the carb heat system isn’t adding to the challenges...

 

The delay of the two colder EGTs rising... this might be related to the secondary jet getting closed down...

 

It might be something to look forward to... getting the jets cleaned... like cleaning fuel injectors...

 

 

PP thoughts only, not a mechanic...

Best regards,

-a-

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1 hour ago, MIm20c said:

Do you have any pictures of your plane from the side showing the cowl flaps open?  Or can you measure the opening?

No, but they measure 1.5" at full open per the maintenance manual.  

I may have tried opening them wider, but it didn't make a difference.  

 

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Paul had made this comment twice (on both profiles).  Stated they wanted to avoid seeing the FF going up and down when doing the GAMI spread test.  

I'm not sure what to make of that.  Both flights I was very carefully leaning with the vernier knob. Very steady, no back and forth.

I'm not sure what he means when he says going up and down, or why it would do that.

Screenshot_20200408-191419_Email.jpg

Edited by ragedracer1977
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Here is what the baffles are supposed to look like.  Seal and gaps that you can, seal around the starter and alternator/generator, make sure that the forward lip seal engages the aluminum grooves in the nose cowl.

Make sure that the lower tie rods aren’t pulled too tight restricting the opening between the Mooney baffles and the Lycoming inner cylinder baffles.

Clarence

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8 hours ago, ragedracer1977 said:

No, but they measure 1.5" at full open per the maintenance manual.  

I may have tried opening them wider, but it didn't make a difference.  

 

That doesn’t sound right to me. The c’s have terrible aerodynamics at the front end. Add to that the oil cooler adding a slight amount of air on the wrong side of the cylinders means you need extra negative pressure to pull the air down. Are the cowl flaps flush when retracted?

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Paul had made this comment twice (on both profiles).  Stated they wanted to avoid seeing the FF going up and down when doing the GAMI spread test.  
I'm not sure what to make of that.  Both flights I was very carefully leaning with the vernier knob. Very steady, no back and forth.
I'm not sure what he means when he says going up and down, or why it would do that.

I would check the mixture cable connection on the engine. Check the arm is tight and and have a helper working the vernier knob to make sure it’s moving the arm in a continuous motion. I would also check for any fuel leaks.
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1 hour ago, MIm20c said:

That doesn’t sound right to me. The c’s have terrible aerodynamics at the front end. Add to that the oil cooler adding a slight amount of air on the wrong side of the cylinders means you need extra negative pressure to pull the air down. Are the cowl flaps flush when retracted?

It is.  It’s actually 1.1”.  

D9423B4C-2485-4F28-91B0-0DBCB809D63E.jpeg

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2 hours ago, M20Doc said:

Here is what the baffles are supposed to look like.  Seal and gaps that you can, seal around the starter and alternator/generator, make sure that the forward lip seal engages the aluminum grooves in the nose cowl.

Make sure that the lower tie rods aren’t pulled too tight restricting the opening between the Mooney baffles and the Lycoming inner cylinder baffles.

Clarence

Was there meant to be pictures?

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6 minutes ago, ragedracer1977 said:

It is.  It’s actually 1.1”.  

D9423B4C-2485-4F28-91B0-0DBCB809D63E.jpeg

Is that the same manual where the cylinder redline is 500 ish...if so you’re fine...  one inch is not enough IMO and you’ll get dead air around cylinder 4. Again just an opinion from an armchair mechanic playing with the kiddos this morning. 

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