M20J Muffler shot - AME says its because I fly LOP

[PTK]

Sorry, PTK, but Weber gas grills are made in china starting about 2007.

They are still far better than the others offers, though.

Byron, I have heard that before. But before I bought it I called Weber. They assured me the high end Webers are made here.

[Guest]

Sorry, PTK, but Weber gas grills are made in china starting about 2007.

They are still far better than the others offers, though.

Weber Broil King BBQ headquartered in Waterloo Ontario Canada, with manufacturing in both Canada and the US. The owners are clients of mine, with yes a Mooney, say that they also have to build in China only to match the low end market of their competitors.

Clarence

[DS1980]

I'm still trying to figure out when this thread went from exhaust to grill.

 

Oh, its PTK. I should have known. He's the guy that didnt believe Camguard when they said they were now required in rebuilt Continentals. Where did that get him? Oh yea, to the truth.

[jetdriven]

Hi all, total time is 1350 since new. Maybe it was just time. It was pressure tested 38 hours ago and was fine - now it's got a big hole in it - hence the questions.

so how was it operated during the whole 1350 hours? LOP? ROP?

[yvesg]

My previous BBQ grill burner lasted only a few years. I got a new one this year using my Visa card points. In order to make it last longer shall I stop running it LOP?

[drbob]

Anyone aware of Inconel (625) being used for replacemant headpipe/muffler replacemant parts?

   

  Newer cars use it,

                           IIRC Mooney uses  321 SS where the Lead, heat & vibration degades -with subsequent cracking.

Smith aAerostar Piper PA 602,use Inconel in their exhaust system,

Lycoming also use Inconel/sodium  for HD (parallel valve) 320/360 supercharged exhaust valves.

   I asked a large AC exhaust sys rebuilder if this could be used at (my)  xtra expanse, NOPE was their reply.

Saw a relatively low time extensive/expensive system OH by this same shop cracked before 50Hrs in service!

 Hoping to recruit comments from the Brain trust here!  Comments--- 

                                                                                                      drbob

[carusoam]

Inconel is a brand name for a supplier of different types of stainless steel. Expect the alloy for sheet metal may be different than machinable parts. (Not always true).

In the chemical industry their alloys are used for high temperature and chemical resistance.

Getting the proper resource is key to defining the solution to your mission.

An aviation exhaust expert with a history of wide experience will be helpful...

For the C, it won't be as critical as a TC'd Bravo.

For me and my old C, my mechanic sent it out to be welded. Often your MSC is a resource for parts like these. The exhaust system is also the heat system and has a tendency to wear out every 40years or so.

Are you looking to build a nice new one?

Best regards,

-a-

[drbob]

Yes,

         Inco (Inconel) is branded and owned by Special Metals Corp. --originally developed for the Whittle (jet) in the '40s.

mostly Ni and Chrome.

The HD valves for the  0360A, --fairly heavy and non magnetic except for the 1 3/8" near the tip,

prob how the sodium was included to the valve.

  Inco 625 --- the weldable one & Burns & IIRC Wolfe aircraft make the tubes, indeed 5 new head pipes would be optimal.

    The inconel sheet i'v worked with is non manetic, heavy and quite tough.

An associate & fellow Mooney driver  is [ DER] and we work on Mooney related projects.

                                                                         drbob

[Bolter]

Yes,

         Inco (Inconel) is branded and owned by Special Metals Corp. --originally developed for the Whittle (jet) in the '40s.

mostly Ni and Chrome.

The HD valves for the  0360A, --fairly heavy and non magnetic except for the 1 3/8" near the tip,

prob how the sodium was included to the valve.

  Inco 625 --- the weldable one & Burns & IIRC Wolfe aircraft make the tubes, indeed 5 new head pipes would be optimal.

    The inconel sheet i'v worked with is non manetic, heavy and quite tough.

An associate & fellow Mooney driver  is [ DER] and we work on Mooney related projects.

                                                                         drbob

 

Inconel *was* a trademarked brand name, back when it was invented as a high temperature nickel alloy, but is now a standard name for this alloy.  It was the enabling alloy for the beginning of the jet age, and is still used throughout many jet engines.  You can source Inconel from many places here and abroad against several standard specifications.  AMS 5662 and 5663 are common ones.  If you are getting Inconel parts from China, be careful to specify standard they are making it to.  The Chinese equivalent for many alloys are much looser than the AMS/ASTM/SAE equivalents. 

 

It is denser than typical steels (.300 lbm/in3 vs .283 lbm/in3, typical), has much higher fatigue properties than most steels, and a significantly higher temperature range.  There are cast and forged variations of the alloys.  The most common in my experience (not necessarily a fact) is IN718 for bar stock, and IN713 for casting.  

 

-dan

[DAVIDWH]

Not sure about you guys, but I bought a Mooney to go fast, NOT TO SAVE MONEY. Love ROP.

 

Now the expenses involving the golf cart to move it in and out of the hanger, that is a story for another time.

[drbob]

Maybe Weber can get their Chinese grills made with Inconel parts,

    how cool would that be? 

                                                      drbob

[jlunseth]

LOP lowers CHT but raises EGT.  If you fly 125 ROP, an equivalent setting LOP might be 30 degrees LOP.  That difference is EGT.  Degrees ROP or LOP means that the EGT's are that many degrees cooler than peak EGT.  So in our example if your EGT when you are flying 125 ROP is say 1450, that means that peak EGT is 1575.  So if you fly the equivalent power setting of 30 LOP, the EGT's are 1545, or 90 degrees hotter than if you were 125 ROP. 

 

When I run ROP, my EGT's are generally in the range of 1450 and the CHT's are about 380.  CHT's depend a little on altitude, the higher air being less good at cooling the cylinders, so the CHT's may be a little higher or lower depending on alt.  When I run LOP my EGT's are around 1550 but the CHT's are cooler, around 320.

 

Which do you want, cooler valves and exhaust system, or cooler cylinders.

[jetdriven]

Actually they did a study back in the 1940s and peak valve temperatures were found at 40 ROP.

[231LV]

At my 50 hour inspection the AME reported that the muffler is shot and pieces of it is actually gone. He asked if I fly LOP - I said I do on occasion. He said that's the reason. Anyone else have an opinion in this regard?

 

50 hours ago the muffler was pressure tested and found to be fine - now it's a mess.

Bwhahahahah! Get a new mechanic!

[philiplane]

If your mechanic doesn't understand the effects of LOP vs ROP on all components, then you need a new mechanic. 

 

Exhaust systems fail due to age and thermal cycles. Peak EGT operations are what kill exhausts early.

 

Any piece of metal exposed to 1400-1500 dF temperatures for over 1000 hours doesn't owe you a thing.

[aaronk25]

2gallons per hour is $12 per hour. In 333 hours I could replace a complete power flow exhaust with the money saved.

If it makes it 1,000 hours that's 3 times....

[jetdriven]

We have ran ours 600 hours. LOP including the occasional LOP takeoff and the muffler is still good. Not to mention it was old when we bought the plane.