Why does my Rocket have a dent in its exhaust?

[SpamPilot]

OK, so I finally had the lower cowl off of my new-to-me Rocket, and I discovered this:

What's up with that?  Does anyone else have this mod?

[RLCarter]

Looks like it got dropped at some point

[Shadrach]

2 hours ago, SpamPilot said:

OK, so I finally had the lower cowl off of my new-to-me Rocket, and I discovered this:

What's up with that?  Does anyone else have this mod?

Is it a dent? It looks like a flat spot.

[takair]

Is the discoloring powdered?  Be sure you don’t have a pinhole leak there.  Alternately, do you have cool air blowing on that spot through the cowl?  Variation in local temperature will tend to change the color of the exhaust.  

[Hank]

18 minutes ago, Shadrach said:

Is it a dent? It looks like a flat spot.

It looks concave to me, as if something hit it (but not the floor). 

[FoxMike]

Someone might had a problem getting two parts of the exhaust  to fit and decided to use some brute force with a hammer.  Watch that for leaks.

[M016576]

Almost looks like someone hit it with a peen-

the discoloring could be a “chicken or egg” discussion- maybe the heat caused the discoloring and the indentation?  Maybe the indentation caused the localized heat, discoloration?  Just guessed on my part- I’m no expert in this arena

Edited January 2, 2019 by M016576

[EricJ]

2 hours ago, Shadrach said:

Is it a dent? It looks like a flat spot.

Shoulda raised the flaps on touchdown.    Wait, wrong thread... 

[jetdriven]

That dimple can erode from the inside and leak. A large leak on a turbo airplane can be very serious. It may torch anything in its path. 

Edited January 2, 2019 by jetdriven

[Yetti]

In big pipelines they call those anomalies. Reading accidents reports, you learn that being on the turn in the pipe is where things erode quicker and cause things to go boom.  In the cessna 400s they replace the exhaust tail pipes on time because if they leak, there is a wing spar that will melt.  Also don't think those oil lines should left to rub on the engine mounts.

[R.May]

I second Yetti above.  That exhaust needs to be looked at.  Pulling the exhaust, while a supreme pain, will let you rest at ease that there are no unseen cracks elsewhere.  You would be surprised...

I flew (2) Rockets for work for over 1000hrs.  Good plane.  I assisted with lots of maintenance and worked through many issues.  You MUST keep an eye on the exhaust.  We would crack the cowl for a look:

-within 1hr of annual maintenance or any heavy engine maintenance; and,

-every 25hrs.

ALWAYS be on the lookout for exhaust dust on or around the exhaust manifold.

Below is one of my photos of exhaust.  No dent.

[Guest]

5 hours ago, R.May said:

I second Yetti above.  That exhaust needs to be looked at.  Pulling the exhaust, while a supreme pain, will let you rest at ease that there are no unseen cracks elsewhere.  You would be surprised...

I flew (2) Rockets for work for over 1000hrs.  Good plane.  I assisted with lots of maintenance and worked through many issues.  You MUST keep an eye on the exhaust.  We would crack the cowl for a look:

-within 1hr of annual maintenance or any heavy engine maintenance; and,

-every 25hrs.

ALWAYS be on the lookout for exhaust dust on or around the exhaust manifold.

Below is one of my photos of exhaust.  No dent.

Sure looks like a dent to clear the lower engine mount tube?

Clarence

[Cody Stallings]

My Mooney has the same dent just outside of the Turbo.

 

R.May is that some type of sleeve on the motor mount tubing?

I could sure use whatever that is, my engine mount is showing some signs of COOKING in that same area.

[FloridaMan]

On 1/1/2019 at 7:09 PM, SpamPilot said:

OK, so I finally had the lower cowl off of my new-to-me Rocket, and I discovered this:

What's up with that?  Does anyone else have this mod?

Is there a cable in the vicinity that somebody could've done this to create clearance for something? it's not unheard of. 

[FloridaMan]

[thinwing]

I’d think the rocket folks could answer this dent question

[Guest]

8 hours ago, Antares said:

Based on many twin Cessna airplanes I’ve worked on, I would say that your tail pipe “vee” clamp is grossly over torqued.  I’ve never seen one so tight that the clamp ends touched.  If the ID tag is still on the witness wire, it will specify the torque valve, this is of course based on the correct nut and bolt being installed.

Clarence

Edited January 4, 2019 by M20Doc

[gsxrpilot]

You really gotta be careful posting pictures under the cowl of your Mooney on this site. @M20Doc or @Yetti or someone will discover some issue you weren't even asking about. And now there's a whole new issue to keep you up at night worrying while it lightens your wallet.  

[Guest]

1 minute ago, gsxrpilot said:

You really gotta be careful posting pictures under the cowl of your Mooney on this site. @M20Doc or @Yetti or someone will discover some issue you weren't even asking about. And now there's a whole new issue to keep you up at night worrying while it lightens your wallet.  

It’s an advantage to seeing many different types of airplanes pass through the shop.  More than a one trick pony.

Clarence

[gsxrpilot]

Just now, M20Doc said:

It’s an advantage to seeing many different types of airplanes pass through the shop.  More than a one trick pony.

Clarence

And a HUGE benefit to those of us on the forum.

[RLCarter]

@M20Doc does have eagle eyes or better. My IA is the same way (must be part of the training), but in all honesty I wouldn’t have it any other way, much easier to fix on the ground than deal with it in the air 

[ohdub]

My J is in the Doc's shop right now for her annual. Like every year, I really hope that there is nothing wrong for his eagle eyes to see, but if there is, I'm glad that it'll be fixed!

[RLCarter]

3 minutes ago, ohdub said:

My J is in the Doc's shop right now for her annual. Like every year, I really hope that there is nothing wrong for his eagle eyes to see, but if there is, I'm glad that it'll be fixed!

Yep
Me: Give me the bad news
IA: this ??? needs fixed
Me: Ok, now the good news
IA: I fixed it

[Guest]

47 minutes ago, ohdub said:

My J is in the Doc's shop right now for her annual. Like every year, I really hope that there is nothing wrong for his eagle eyes to see, but if there is, I'm glad that it'll be fixed!

A little something I built for your new EDM install.  Transducers and wires on top, hoses in the bottom.

Clarence

[ohdub]

31 minutes ago, M20Doc said:

A little something I built for your new EDM install.  Transducers and wires on top, hoses in the bottom.

Clarence

Looks awesome, thanks Clarence!