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Posted

Does any one know why some Mooney's exhaust come with one additional slip joint on cylinder number 4?   If this additional joint on your Mooney, you'll have a clamp similar to the one shown in the picture below.  

 

image.png

Posted

I don’t know about the clamp... but...

1) is that exhaust stains of exhaust leaking out of the slip joint?   If that is an exhaust stain... how is your CO monitor doing?
 

2) what is wrapped in a fire proof sleeve that is sitting against the exhaust pipe?

The pic might be a bit misleading...

But if high temperature silicone IS sitting against the high temperature exhaust tube... that would be iladvised...

It kinda looks like it is getting cooked.... cooked rubber won’t work like new rubber...

remember those polymer discussions?

Best regards,

-a-

 

 

Posted

The picture is not from my Mooney.  I found it on Google image.  

My Mooney has a similar clamp.  My IA friend saw the clamp and commented that it look like a patch job.  A search on Google found the exhaust clamp is indeed from the factory.   

m-20_200_slip_rib_m20j_1.png

  • Like 1
Posted

Expect the slip joints to absorb the movement of all the parts when they grow with heat and shrink when they cool...

If you review each exhaust pipe they are going to absorb the change in length.

It seems each one has a different geometrical challenge...

That one got the clamp...

I bet Clarence may know the detail behind it... Invite him to the conversation if you really want to know... :)

Best regards,

-a-

Posted

Yes, I do really want to know!!   While Mooney design is old, I have found almost nothing is designed for the sake of expediency.  I'm sure there is a reason why this cylinder #4 down pipe end up with two slip joint and one of its joint has a clamp!!

@Clarence 

Posted

To get Clarence’s attention... invite @M20Doc...

He has tremendous Mooney mechanical skills and many Mooney documents... that is typical of the worlds best MSCs.   :)

Although, your pic and drawing are perfect for supporting the conversation...

Best regards,

-a-

Posted

A slip joint and clamp on the stack for cylinder 4 is factory installed.  I don’t know why it’s there on J models and not on older models, I’ve seen it come apart a few times.

The replacement system sold by Kinsey Welding does not have this slip joint.

Clarence 

Posted
28 minutes ago, 67 m20F chump said:

Hey corn flake.  What’s zip tied to your fuel line?

The photo is from a picture he found on Google and not his Mooney

Posted
3 hours ago, 67 m20F chump said:

Hey corn flake.  What’s zip tied to your fuel line?

Its looks like the power line for a heater element. Given the proximity of the thermocouple wire coming out from the cylinder above I'd think a Tannis combination CHT/Heater probe.  

Posted
1 hour ago, corn_flake said:

@M20Doc  Since you have seen few that came apart, can you share if it is a catastrophic failure to the engine operation if that happens while in flight?  

I had an exhaust riser break in flight which would be much like if this clamp came apart and it was on #4 by coincidence.  The only thing that happened was a rhythmic thumping noise that changed with a change in power (the exhaust actually exiting into the engine compartment instead of out the exhaust pipe) and it going almost silent when the power was brought to idle.  Also, the EGT's on #4 went cold because most of the exhaust was venting out by the engine and not out the actually pipe where the probe is.  But the airplane flew just fine and nothing catastrophic happened other than the bill I got to fix it. :)

#4 Exhaust failure (3).jpg

Posted
7 hours ago, Greg Ellis said:

I had an exhaust riser break in flight which would be much like if this clamp came apart and it was on #4 by coincidence.  The only thing that happened was a rhythmic thumping noise that changed with a change in power (the exhaust actually exiting into the engine compartment instead of out the exhaust pipe) and it going almost silent when the power was brought to idle.  Also, the EGT's on #4 went cold because most of the exhaust was venting out by the engine and not out the actually pipe where the probe is.  But the airplane flew just fine and nothing catastrophic happened other than the bill I got to fix it. :)

#4 Exhaust failure (3).jpg

Greg,

How long was a flight after failure?

I can see significant exhaust deposits on cylinder fins and by the spark plug.

This happened also to my 14M during the takeoff few months after purchase. We heard a pop and sound changed  and i elected to land. Cost for repair was not bad at all.

Posted
10 hours ago, corn_flake said:

@M20Doc  Since you have seen few that came apart, can you share if it is a catastrophic failure to the engine operation if that happens while in flight?  

The sound the engine makes changes, exhaust soot goes everywhere as shown in the pictures above.  Longer term I think melted wires etc and fire would be the biggest danger, but the change in engine sound should be an indication of trouble.

Clarence

Posted

Summary...


Exhaust exiting under the cowl has two significant effects...

1) 1,500°F (or so) gasses inpinging on Meltable and burnable items.... expect a fire to be a strong possibility. There are rubber oil return lines in the neighborhood... and fiberglass resin may be affected by it as well...

2) the exhaust has a fair amount of CO in it and releasing it under the cowl would be sub-optimal...

 

Signs of the leak...

1) Dusty deposits and soot in the neighborhood of the leak...

2) Change of exhaust sounds.

3) Change of EGT on the effected pipe.

 

Great discussion, and pics too!

Best regards,

-a-

Posted
20 hours ago, Igor_U said:

Greg,

How long was a flight after failure?

I can see significant exhaust deposits on cylinder fins and by the spark plug.

This happened also to my 14M during the takeoff few months after purchase. We heard a pop and sound changed  and i elected to land. Cost for repair was not bad at all.

I flew it for about 10 minutes.  I was heading to Missouri and was in the middle of no-where.  It was extremely cold outside and the CHT's were quite low.  I chose to continue to my destination because the plane was doing fine and there were no other issues.  CO monitor stayed at 0 so there was no CO getting into the cabin.  And I was joking about the cost.  It was not bad considering they had a new part made. 

  • 2 years later...
Posted

I think the reason there is a clamp comes down to the three leg stool. They don’t rock. A four legged stool will rock. The same applies to the exhaust, you can get three pipes to sit flat, but thr fourth is a problem. Mooney made the fourth pipe adjustable so all four will sit flat.

I f you need a new clamp, there is one for sale on EBay

https://www.ebay.com/itm/133891910328?chn=ps&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&itemid=133891910328&targetid=1645685074048&device=c&mktype=&googleloc=9030089&poi=&campaignid=16730423415&mkgroupid=135815925780&rlsatarget=pla-1645685074048&abcId=9300841&merchantid=109942766&gclid=EAIaIQobChMI_6v5lfaM-gIVRxvUAR0CuAltEAQYAiABEgKUafD_BwE

 

  • Like 3
Posted

My 68 G model has a clamp on one exhaust, I think #4. It came up during my annual because the IA commented it didn't look right.  Ultimately we decided since it wasn't causing a problem and there were no leaks we would leave it be.   Sounds like it's supposed to be there?  I have the O 360 A1D engine.  

  • Like 1
Posted

Per I believe lycoming, you can get the proper clamp from Napa. I just had to replace this on my J. The previous Owner or somebody before me had two host clamps safety wired trying to keep the slip joint intact. It was the most non-aviation thing I've ever seen.. And when we did a leak test, well. It was not sealed at all... 

I'll look for the doc on this, but a normal stainless steel clamp is acceptable. This is the part from lasar: https://lasar.com/power-plant/clamp-alternate-for-c10x-30cc10y-30-6c-930030-501

My mechanic had the lycoming doc that stated this. I can't find it online. so far..

 

Just a private pilot/plane owner. This may not work for you, and may be specific to my plane only...

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