Transition Turbo pipe crack

[Houman]

Hi,

After my little worries couple of weeks ago with the Rocket, I had my trusted mechanic take a complete look at the engine, good news is that engine is fine, bad news is we found 2 issues, 1st is an oil leak from the quick drain plug and more serious is a small crack in the Transition Turbo pipe...

The crack is half of an inch at a join, my mechanic says that the whole pipe is one piece and needs to be replaced or repaired...

I already called Rocket Engenierring this morning, but I guess they are still a sleep on the west coast, but was wondering if anyone has seen this and what kind of cost figures am I looking at.

Thanks for any opinions...

[aviatoreb]

Not the exhaust pipes but a turbo pipe?

[Houman]

Yeah, going from the engine right Under the cylinders to the turbo...

[aviatoreb]

Oh - I don't know anything about that.

 

I asked if it was exhaust since I had an exhaust crack about 3 years ago - actually we found it by my CO monitor.  I checked my airplane into the mechanic when my airplane started reporting 50-70ppm of CO in the cabin whereas it was previously in the 0-2ppm reading range (and it is again).  No other indications of problems since this was an early indicator of a developing problem.

 

Turns out I had a crack in the exhaust.  Rocket said send them the exhaust system and they would replace at a reasonable cost - which they did - they wanted to do that instead of having me repair the crack which was permitted since at some point they realized that there were too many cracks occuring in general so they were upgrading to thicker stock materials.

 

So.....I wonder if the same is true for your pipe crack - wherever it is.  When was the conversion done.  I wonder if it is pre or post thicker stock?

[Houman]

Not sure if it is the thicker stock or not, since I have nothing to compare it with. From the mechanic's indication, it is the Transition Turbo pipe, it's like a spyder 6 path metalic tubes that leave the engine and join up to go to the turbo and also the exhaust, so not the exhaust it self, but just before.

 

Thanks for the info, maybe Rocket can do the same for us, not sure how long it would take... Can you tell me here or IM me on what was the turn around time and cost...

 

Thanks !!!

[Skywarrior]

Had a similar problem discovered during the Pre-buy when purchasing my Bravo. The transition pipe was severely pitted (from excessive heat). Shop sent the transition pipe to a company in Canada, who welded over the pits and sent it back.

 

$5,000

 

New would be better than repaired.

[Houman]

Had a similar problem discovered during the Pre-buy when purchasing my Bravo. The transition pipe was severely pitted (from excessive heat). Shop sent the transition pipe to a company in Canada, who welded over the pits and sent it back.

 

$5,000

 

New would be better than repaired.

5000$ for the repair ???

[aviatoreb]

Hi Formation,

 

I will say here so the others know - I don't remember how much it cost.  It was a pretty quick turn around like a week or two. I don't remember specifically as it was a few years ago.  The cost was surprisingly reasonable in my opinion but the overall cost was pretty expensive since the parts are in the heart of the engine areas and it is a very tight space to work in to do a major repair - so the hours was pretty high.  I want to say it was something like 4 or 5k total incl labor.

 

Now - remember I am not a mechanic - so I do not even know if your part is connected to the big pieces I had replaced with thicker stock - or maybe you already have it - in which case maybe you send your parts in for welding repairs.

[Houman]

Hi Formation,

 

I will say here so the others know - I don't remember how much it cost.  It was a pretty quick turn around like a week or two. I don't remember specifically as it was a few years ago.  The cost was surprisingly reasonable in my opinion but the overall cost was pretty expensive since the parts are in the heart of the engine areas and it is a very tight space to work in to do a major repair - so the hours was pretty high.  I want to say it was something like 4 or 5k total incl labor.

 

Now - remember I am not a mechanic - so I do not even know if your part is connected to the big pieces I had replaced with thicker stock - or maybe you already have it - in which case maybe you send your parts in for welding repairs.

Ok, thanks, I hope it is not as major, too bad it can't be welded in place...

[Houman]

Just talked to Lyn from Rocket, very nice and helpfull guy, now we are off to see if we had the AD applied and see if we had the old or the newer piping... The fun begins...

[carqwik]

Not sure if this is the same as I had, but last annual Top Gun found a small crack in the "exhaust collector" which I think is the same thing you're describing...it's where the exhausts from each bank of cylinders comes into one unit prior to the hot side of the turbo.  They removed this part with the flange and sent it to a shop in San Diego area to be rebuilt...total cost was very reasonable (< 1 AMU).

[carusoam]

In the event of TC failure to operate....

At what altitude does the lower CR TC'd engine restart?

This is a question that comes up after a recent engine out of a TC'd plane at 17k', combined with known (mis-used) exhaust clamp issues on the Bravo.

Is there an emergency restart procedure for low compression engines with TC inop?

Either way, be aware of the critical nature of the pipes leading in or out of the TC.

We love to save Mooney Money. Just be aware of the technical details...

This is intended to be informational. Not confrontational.

Best regards,

-a-

[jlunseth]

Yes, that is the "collector" on a turbo.  If Rocket fails you and you can't find a used part, that may be something that can be made up for you under the "owner fabricated part" rules.

 

Don't dismiss the quick drain issue lightly though.  I once did an emergency descent and landing from 19k in the dark over Canada, descending through IMC, because of a leaking quick drain.  We had blown all the oil out during about 2 1/2 hours of flight from KFCM and over Lake Michigan.  Running the engine pressurizes the crankcase and if the quick drain is not sealing it will blow oil out.  It takes very little to stop the quick drain from sealing completely.  In our case it was a tiny sliver of plastic about 1/16th inch thick but long, that passed through the quick drain inlet but would not pass through the valve at the bottom.  You can get a kit to redo all the seals on a quick drain and I would highly recommend having your A&P do that.  Another word of warning is that I found from regrettable experience that A&P's are fairly dismissive of quick drain issues, I had my quick drain checked by one immediately prior to the fateful flight and he said a little leakage was "normal."  Leakage of any kind from the quick drain is not normal and is a sign of a problem.

 

carusoam -  My 231 POH says restart is after (lower than) 12,000, and if it has been a long enough cold descent there are issues with power up immediately.  The engine must be warmed at low power first, I believe the primary issue is low oil temp especially at the TC bearing.  According to my POH, cold oil temp can cause engine stoppage if high power is applied.   

[jojogunn]

Give Dawley a call.  They are a first rate outfit in Wisconsin.