Mooney M20C Air Box Woes

[jghyde]

I have a 1964 M20D that the factory converted to an M20C "Frankenstein" after an incident on the year it was born. It has an E model gear and an O360-AID with the fancy prop.

Flew it out to Florida to have the Power Flow installed on it. Got here and the air box basically was disintegrated along with the accordion flexible coupling. It passed inspection during Feb 2022 annual and I've been flying a bunch of hours on this plane.

No one has air boxes like these. Mine is a waste of time to repair I think. Too many problems. Laser has an aftermarket air box that may work for $2200. The exact part is special order for $2500 from Laser. This is too many AMUs and delivery time too long. I need to get the air box replaced and the Power Flow installed and back to Texas this week. 

I found an M20G air box that I think will work. Also found a J-model accordion flexible coupling. We will see if I can Frankenstein this thing back to life. The stuff is supposed to arrive Wednesday via FedEx from all over the country. Will keep you updated.

Edited January 10, 2023 by jghyde

[Jim Peace]

sent you a PM

[jghyde]

17 minutes ago, Jim Peace said:

sent you a PM

Thank you! Will keep you updated.

[Igor_U]

That's a big crack, it has been there for a while and then fell apart. Perhaps you can find used part, C of that age should be reasonably easy to find? I would be surprised that J "accordion" intake duct would fit as looking at pictures, seems different size. 

Good luck 

[Mcstealth]

Did yhe parts show up?

[jghyde]

2 hours ago, Mcstealth said:

Did yhe parts show up?

Parts arrived. Praying they work. Someone quoted me $600 for that accordion. I'm trying the j-model version first.

[Guest]

J model doesn’t have an intake coupling.

[carusoam]

If ever there was a part that could use factory support to ‘Re-design’ (change the material) a new one…

The air intake made from ‘60s materials would be it…

The 60s materials physically can’t last long enough.

People that make modern engine intakes are pretty easy to find…. Well, a little more challenging lately. (There is an MSer that builds modern intakes for various planes and cars, document a few times around here)

0.6 AMU for a part that is expected to have holes worn through it in a few years, and have the owner annoyed by dirt entering downstream of the filter without much warning until the next annual…

 

How would you get that on the priority list at Mooney…?

They are still in the spare parts business.

Kind of low hanging fruit for the remaining engineers…

High benefit for the customers…

 

Right up there with donuts for the Mite community… none available anywhere…

I’m sure selling the old style intake at 0.6amu isn’t going to keep Mooney spare parts business alive…

if it does… they should have plenty in stock or on demand…

PP wondering out loud only… somebody could send a request / fyi over to @ jonny….

Best regards,

-a-

[Sabremech]

7 hours ago, M20Doc said:

J model doesn’t have an intake coupling.

I wonder what the logbook entry for this maintenance is going to look like? 

[Guest]

7 hours ago, jghyde said:

Parts arrived. Praying they work. Someone quoted me $600 for that accordion. I'm trying the j-model version first.

Don’t throw the old one away, it’s repairable.

[FlyingDude]

Can't your AP just build a replica? AMTs are required to know sheet metal working... Will definitely cost you multiple hours of his time but better than grounding the plane or scavenging just-as-old parts...

Just thinking out loud...

[N201MKTurbo]

I have a friend who makes custom turbo and exhaust systems for race cars. He could fabricate one of those air boxes (and he is an A&P).

I'm wondering how many could be sold and how much you'll would be willing to pay for one? It might be worth the effort to get a PMA if a few hundred could be sold for a couple of AMU each.

There is a lot of welding on that airbox. I'm thinking a good fast welder will take an hour or more to weld one of those. With a couple of more welds it could be made without a stamping die. If I was going to go the PMA route I would use a little thicker material.

[jghyde]

Can't your AP just build a replica? AMTs are required to know sheet metal working... Will definitely cost you multiple hours of his time but better than grounding the plane or scavenging just-as-old parts...
Just thinking out loud...

I’m not at home station. I need to get this done quickly. Nonetheless found a G-model air box circa 1968 that appears as good as new.


Sent from my iPhone using Tapatalk

[jghyde]

I’m not at home station. I need to get this done quickly. Nonetheless found a G-model air box circa 1968 that appears as good as new.


Sent from my iPhone using Tapatalk

Sent from my iPhone using Tapatalk

[jghyde]

I wonder what the logbook entry for this maintenance is going to look like? 

I honestly don’t know what model Mooney that accordion came from. It was found in storage at Ranger Aviation in San Angelo. They used to be an MSC I think. The guy told me he thought it was for a newer Mooney like a J model. But Js are fuel injected.

The final verdict is the accordion was the exact part.


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[jghyde]

If ever there was a part that could use factory support to ‘Re-design’ (change the material) a new one…
The air intake made from ‘60s materials would be it…
The 60s materials physically can’t last long enough.
People that make modern engine intakes are pretty easy to find…. Well, a little more challenging lately. (There is an MSer that builds modern intakes for various planes and cars, document a few times around here)
0.6 AMU for a part that is expected to have holes worn through it in a few years, and have the owner annoyed by dirt entering downstream of the filter without much warning until the next annual…
 
How would you get that on the priority list at Mooney…?
They are still in the spare parts business.
Kind of low hanging fruit for the remaining engineers…
High benefit for the customers…

 
Right up there with donuts for the Mite community… none available anywhere…
I’m sure selling the old style intake at 0.6amu isn’t going to keep Mooney spare parts business alive…
if it does… they should have plenty in stock or on demand…

PP wondering out loud only… somebody could send a request / fyi over to @ jonny….
Best regards,
-a-

Carusosm— your best pontification yet! I wonder if old C models should start using the circular air box for the O360 on the RV-8


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[mike20papa]

I rebuilt mine, but not near as deteriorated as the one on your AC.  I had a crack along the width of the box, on top,  I formed a new piece of aluminum and made new carb heat "apparatus".   My welder told me the box was loaded up with so much intergranular corrosion that made the repair extremely difficult.  Aluminum oxide melts at such a higher temp than raw aluminum, it will drop out like water.  Unless you've welded aluminum, it's difficult to explain.  My repair included new MacFarlane bearings (non ingestible needle bearings) and more.  Best of luck.  

[Sabremech]

3 hours ago, jghyde said:

I honestly don’t know what model Mooney that accordion came from. It was found in storage at Ranger Aviation in San Angelo. They used to be an MSC I think. The guy told me he thought it was for a newer Mooney like a J model. But Js are fuel injected.

The final verdict is the accordion was the exact part.


Sent from my iPhone using Tapatalk

Pretty straight forward with the right parts. Going off what you originally posted was going to be interesting. Sounds good though now. 

 

[carusoam]

11 hours ago, jghyde said:

Carusosm— your best pontification yet! I wonder if old C models should start using the circular air box for the O360 on the RV-8


Sent from my iPhone using Tapatalk

hmmmmmmm….

Something to add to the list for @Sabremech…

His cowling project has improved cooling that was inspired by other modern planes… (possible RV?)

An improved intake might be a relatively straight forward add on…  (not easy, straight forward) 

The cowling project is covered by all the proper documents… (SabreMech has the complete skill set…)

Best regards,

-a-

[N201MKTurbo]

1 minute ago, bluehighwayflyer said:

I don't need it right now and probably never will if I were to acquire a PMA'd spare such as this, Rich, but count me "in" if you and/or your friend were to ever undertake such a project.  We need more people like you and @Sabremech who are willing and able to take on such projects to support our aging fleet.

Unfortunately, I'm super busy right now and don't have any bandwidth to do this stuff. I was going to retire last april, but was poached at the last minute for a number I couldn't refuse. I think I will get this (work, not airplane) thing to market and then take the money and run.

These airplane projects would be fun retirement projects.

[Jim Peace]

On 1/10/2023 at 1:31 PM, jghyde said:

Thank you! Will keep you updated.

I thought you had to leave ASAP back to Texas....did you test fly it?

[jghyde]

14 minutes ago, Jim Peace said:

I thought you had to leave ASAP back to Texas....did you test fly it?

Not yet. I also put on a Power Flow and that took a little longer. However, the Air Box was a blocker to even beginning the PF. I’ll fly out at 0800 Saturday. Air Box woes extended my stay 2 days! 

[Jim Peace]

1 hour ago, jghyde said:

Not yet. I also put on a Power Flow and that took a little longer. However, the Air Box was a blocker to even beginning the PF. I’ll fly out at 0800 Saturday. Air Box woes extended my stay 2 days! 

Wish I had the time to drive up and say hello and to see your plane.  Work keeps getting in my way..

Post your results with the power flow....very curious about real world performance...

[cliffy]

Did you use something other than plastic zip ties to secure the boot to the air box?

[jghyde]

18 minutes ago, cliffy said:

Did you use something other than plastic zip ties to secure the boot to the air box?

Temporary fix until i get back to Texas. Don't shoot!