PowerFlow exhaust on Mooney M20J

[Shawn26]

Anyone recently removed the stock exhaust on a Mooney M20J for PowerFlow? I would like to hear your thoughts on the upgrade and performance! Thanks

 

 

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[Wistarmo]

1993 MSE.  No improvement.  Requires disassembly at annual.

[Shawn26]

1993 MSE.  No improvement.  Requires disassembly at annual.

That’s what I also heard. No improvement on the J. But pre J, yes!


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[philiplane]

I did an M20F and it worked very nicely, improving the rate of climb and the cruise speed just as Powerflow claimed it would. Maintenance has been minimal, using nickel anti-seize on the slip joints is the key.

[wcb]

So how about an F with RayJay Turbo?

[PT20J]

The Powerflow rep at MooneyMAX said that the J exhaust is pretty efficient and that there isn't much improvement to be had from a PF. 

Skip

[carusoam]

Generally, around here...

PF makes a great product...

The exhaust pressure drop is better than stock...
 

But... by the time the J came out...

Things were onto phase two of improvements...

1) Intake was improved significantly...

2) Exhaust was improved as well...

Then the PF was improved too...

Their second version Is a better fit of the external pipe along the the side of the plane...

 

At annual, there are lubrication points to be taken care of... if ignored something sticks and breaks...

Many people opt for the PF when needing to replace a worn or broken exhaust system...

A side issue to check on... there were discussions related to cabin heating...  the Muff may be different in size... and the exhaust doesn’t stay as hot on the inside....

Old PP fuzzy memories...

Best regards,

-a-

[PT20J]

I'm curious: Most everyone that has Powerflow grumbles about how much of a pain it is to disassemble it every year to lubricate the slip joints. Has anyone NOT done this and noticed any problem (or not had any problem)? The reason I ask is that the stock system also has slip joints. Some people don't do any maintenance on these. A lot of mechanics squirt some mouse milk or Aerokroil in them whenever the cowling is off (that's what I do) and never have a problem.

I had an issue with the tail pipe hitting the cowl flap and thought it was due to the ball joint binding. I took it apart and lubed it with C5-A (MIL-PRF-907F, latest version of what Powerflow calls for) and that made it rotate freely. Fifty hours later, I checked it and it was just as tight as before. So, I'm not convinced that the lubrication buys anything after a few hours.

The only requirement to disassemble and lubricate annually I see is in the form of an ICA ,and ICAs are not required to be complied with for part 91 operations unless they show up in a limitations supplement to the AFM. So, I'm wondering if the Powerflow really needs this extra lubrication.

Skip

[cferr59]

My Powerflow was not lubricated for the first 5 years of its life and nothing happened.  It was lubricated last annual.  I didn't personally take it apart, but it seems like it wouldn't be all that hard to do.  How long does it actually take to do the lubrication?

[adverseyaw]

I've talked with two A&Ps who run MSCs, and two current Power Flow owners about their experience with PFs installed in M20Js.

• MSC A&P #1: half of owners like them, half of owners say it didn't make any improvement and isn't worth the money
• MSC A&P #2: most owners like them
• M20J w/ Power Flow owner #1: worthwhile, especially for improvement in CHTs (see links below)
• M20J w/ Power Flow owner #2: didn't make a huge difference, not worth the hassle

From this small sample I agree with MSC A&P #1: half of M20J owners like them, half of owners say it's not worth it.

Owner #1 did a great writeup on MS a while back.

=== BEFORE ===

 

=== AFTER ===

 

[Beechbum]

On 6/4/2020 at 9:48 PM, PT20J said:

I'm curious: Most everyone that has Powerflow grumbles about how much of a pain it is to disassemble it every year to lubricate the slip joints. Has anyone NOT done this and noticed any problem (or not had any problem)? The reason I ask is that the stock system also has slip joints. Some people don't do any maintenance on these. A lot of mechanics squirt some mouse milk or Aerokroil in them whenever the cowling is off (that's what I do) and never have a problem.

I had an issue with the tail pipe hitting the cowl flap and thought it was due to the ball joint binding. I took it apart and lubed it with C5-A (MIL-PRF-907F, latest version of what Powerflow calls for) and that made it rotate freely. Fifty hours later, I checked it and it was just as tight as before. So, I'm not convinced that the lubrication buys anything after a few hours.

The only requirement to disassemble and lubricate annually I see is in the form of an ICA ,and ICAs are not required to be complied with for part 91 operations unless they show up in a limitations supplement to the AFM. So, I'm wondering if the Powerflow really needs this extra lubrication.

Skip

The ICA has an airwothiness limitation section which must be complied with even for part 91. 

[philiplane]

People use a mixture of nickel anti-seize and Mouse Milk to wick into the slip joints at every oil change. It keeps the slip joints slipping, without the hassle of disassembly.

[PT20J]

1 hour ago, Beechbum said:

The ICA has an airwothiness limitation section which must be complied with even for part 91. 

This is correct. I noted this in another thread. The FAA-approved ICA document contains the text below. It is unusual for an ICA to include an airworthiness limitation; most manufacturers avoid that. However, this one does, and, since the limitation requires inspection of the joints after disassembly, applying lubricant externally won't satisfy  the limitation. BTW, the reason for the quotation marks is that this is the exact text that the FAA requires be in an airworthiness limitation section of an ICA.

6.2 AIRWORTHINESS LIMITATIONS
“The Airworthiness Limitations section is FAA approved and specifies maintenance
required under §§43.16 and 91.403 of the Federal Aviation Regulations unless an
alternative program has been FAA approved.”
6.2.1 Mandatory Replacement Time – None. Any collector assembly that is damaged and/or
fails the pressure test described below must be rebuilt or replaced.
6.2.2 Structural Inspection Interval – At 100 hour or Annual intervals, depending on the service
regime of the aircraft. WARNING: Carbon Monoxide gas present in exhaust gases
can lead to pilot incapacitation and/or death. A damaged exhaust system has the
potential to allow Carbon Monoxide into the aircraft cabin. To prevent such an
occurrence, it is imperative that the exhaust system is inspected using the intervals
and procedures described in this report. It is recommended that in-cabin carbon
monoxide levels be measured periodically. Concentrations of greater than 50ppm

Installation Instructions and
Instructions for Continued Airworthiness
Kit: PFS-16201(-GEN2)

PFS-16150-00 Rev G Page 18 of 26 January 30, 2018
will require immediate exhaust system inspection and repair or replacement as
necessary.
6.2.3 All slip joints must be disassembled and lubricated with a high-temperature anti-seize
compound (MIL-A-907E or equivalent) at 500hr or Annual intervals (whichever comes
first). While disassembled, inspect for wear or galling. This should be performed more
frequently if headers seize between inspections.
6.2.4 Structural Inspection Procedure – See Section 6.6.

[Costa Leite]

Dear Mooniacs

 

In our 1998 M20J Allegro, s/n 24-3429, we installed in 2020 the Power Flow Exhaust System.

 

I now realized that we still have the original and complete exhaust system, removed at 1.400hrs and 22years AirframeTT.

 

Today I took the pictures in attach of the original Exhaust System that I keep in my garage.

 

Do you think this is useful to you? If so, would you like to make an offer via PM??

 

 

Kind regards

Fredi

+351 910 690 093

[jetdriven]

2 hours ago, Costa Leite said:

Dear Mooniacs

 

In our 1998 M20J Allegro, s/n 24-3429, we installed in 2020 the Power Flow Exhaust System.

 

I now realized that we still have the original and complete exhaust system, removed at 1.400hrs and 22years AirframeTT.

 

Today I took the pictures in attach of the original Exhaust System that I keep in my garage.

 

Do you think this is useful to you? If so, would you like to make an offer via PM??

 

 

Kind regards

Fredi

+351 910 690 093

I would like this. It I can’t get ahold of you with that number 

[Fly Boomer]

1 hour ago, jetdriven said:

I would like this. It I can’t get ahold of you with that number 

It appears to be in Portugal.  Most cell phones will insert all the appropriate prefix info by inputting the "plus sign".  On mine, I get the "plus sign" by holding down zero for a couple of seconds.  Then dial the country code and the rest.

[Stubby]

Hopefully I'm not beating a dead horse here, but I was wondering if anyone has any pictures of the newer style Powerflow that doesn't look quite so terrible on a Mooney. My J is in for annual right now and I'm going to have to replace the muffler and tailpipe, so I'm most likely going to replace the whole works. The cost of the Powerflow over an OEM set up is noticeable, but not terrible. I'm wondering if, since I'm going to replace everything anyways, Powerflow would be worth it. From what I've read in the numerous posts here, the performance gain on a J minimal, and there is a little more maintenance. I haven't decided either way yet and I guess I'm not even really leaning a certain way yet... What say you?

[BlueSky247]

While we're on subject - I wonder if the 390 would be a different answer for this exhaust on the J.

[201Mooniac]

I think I have the Gen 1 on my M20J but I can get a picture for you when I go to the airport later today.  I presume you are only referring to the exhaust pipe.

[Stubby]

5 minutes ago, 201Mooniac said:

I think I have the Gen 1 on my M20J but I can get a picture for you when I go to the airport later today.  I presume you are only referring to the exhaust pipe.

I should have specified that... I am referring to the exhaust pipe. From what I can see on their website, the Gen 1 and Gen 2 only differ under the cowl.

[201Mooniac]

Here is a picture I for you, if it isn't what you were looking for, let me know and I can try to get something more relevant.

[jetdriven]

I visited these guys at Oshkosh a couple of times and I’m just kind of shocked at how far down the tailpipe sticks out. Now I think the reason for it is that it comes straight out the side of the muffler and it’s bent  one time 90° and that’s the angle it’s going to exit  at.  If  you look at a stock M20J tailpipe  it has two bends in it. It has one bend that turns it aft and has another bend that turns it down. But anyway, I’m like the thing hangs out as far down as the gear door. He said well it doesn’t hang down below the airplane , but when the gear is up it  hangs down 6 inches. Then he wants to claim that it’s so the carbon monoxide can’t find its way into the cabin inlet ob the side, which I don’t understand but anyway, I just can’t get over the tailpipe  hanging down that far . 
 

[ArtVandelay]

Whatever extra power you get will be needed to overcome the additional drag by the PF tailpipe.

[BlueSky247]

I really wish we had more options in that department. A good header system tuned for our cruising/peak rpm bands would make a nice difference in performance and fuel burns.

[Stubby]

1 hour ago, BlueSky247 said:

I really wish we had more options in that department. A good header system tuned for our cruising/peak rpm bands would make a nice difference in performance and fuel burns.

I agree... it seems like if you want to go aftermarket/performance, Powerflow is the only name that comes up. I've done a little digging and can't seem to find any others. At this point it seems like overhauling the existing system or going with a new system from somewhere like AWI makes the most sense.