Yet another head scratcher from an "extensive" annual.

[ragedracer1977]

When I bought my plane, I took it to a place with what I thought had a good reputation.  I told them "leave no stone unturned".  Basically gave them an open checkbook. I've detailed here before the shoddy work done (if it was done at all).  Today, I found more.  

They logged in my books (and charged me for) shimming the engine up.  I've noticed recently that it seemed to be sagging more.  I looked through the logs and couldn't find that new engine mounts had been installed since overhaul in 1989.  Sorta surprised they didn't change them when they had the engine off for what was basically an IRAN in 2012, but whatever.  They did note it was shimmed when reinstalled.  Since it was shimmed in 2012 and ostensibly again in September 2017, I figured it was time to go ahead and replace the mounts.

Well, I seriously have my doubts that they were shimmed in 2017.  Why? Well, first of all, there was only one 1/16" shim on each lower mount. Further they were full shims, only able to be installed by completely removing the engine mounts. If you've ever done the lower mounts on a Mooney C model, you know how much work it is.  If 2 years ago they removed the mounts entirely, when they had an open checkbook,  why would they reinstall mounts with a cure date of 5/1988..... 31 years old.  

And, in my estimation, there's not a chance in heck they looked fine then and look like this now....... Both lower mounts looked like that.

At any rate, I'm really happy it's done, and my spinner lines up great now!

[carusoam]

That is a beautiful pic, Brice!

its all about the smooth lines of symmetry.   

Best regards,

-a-

[RLCarter]

i would say it was time... I replaced mine 3 yrs ago and they are a pain to do

[ragedracer1977]

For reference if you don't know, this it what they look like new.

 

 

[MB65E]

Wow, I’ve never seen one that blown out!!

-Matt

[Don Heene]

I replaced mine, major pain.  When removing the old ones I saw they didn't even line up the pins with the holes for the Lord mounts.  My screws for the spinner were hitting the cowling, that's how i noticed it.   

[larryb]

When I had my J I had the mounts replaced and the vibration in flight was noticeably improved. I did it because they were old, not because of a sag that could not be shimmed. I think there are a lot of airplanes flying around with poor engine mounts because the owners don’t recognize the very gradual deterioration.

[ragedracer1977]

Minor update.  On the post maintenance run-up, we discovered that with the engine in the correct position, the mixture would no longer go to ICO.  The lever hit the sheath on the mixture cable (ran out of travel) about a 1/4" short.  Seems counterintuitive that the bottom of the engine being farther forward would have this result, but it did! 

[N201MKTurbo]

Brice,

The cable should be mounted to something on the engine. I can't tell for sure, but it looks like it may be mounted to the engine mount. If so you need to change this. If it is mounted to the engine mount the mixture will change with engine motion in the mounts.

[Guest]

Brice,

It also looks like there may not be a check nut on the throttle cable rod end.

Clarence

[ragedracer1977]

8 hours ago, N201MKTurbo said:

Brice,

The cable should be mounted to something on the engine. I can't tell for sure, but it looks like it may be mounted to the engine mount. If so you need to change this. If it is mounted to the engine mount the mixture will change with engine motion in the mounts.

Interesting. I believe it is secured to the engine mount.  The cross bar that activates the cowl flaps I think.  

And @M20Doc I'll have a look at that too

[Skates97]

11 hours ago, N201MKTurbo said:

Brice,

The cable should be mounted to something on the engine. I can't tell for sure, but it looks like it may be mounted to the engine mount. If so you need to change this. If it is mounted to the engine mount the mixture will change with engine motion in the mounts.

I would like to see a pic of where and how it is supposed to be secured. My AP/IA replaced all my old control cables earlier this year. I will have to look but I think the mixture cable is secured with a clamp at the firewall but nothing else between it and the carb. This is the clamp he used at the firewall. 

https://www.aircraftspruce.com/catalog/appages/cablesafe2.php?clickkey=19457

[jetdriven]

ThOse  look pretty slick with but the aluminum melts quickly,  not really firewall standard 

[EricJ]

1 minute ago, jetdriven said:

ThOse  look pretty slick with but the aluminum melts quickly,  not really firewall standard 

I think they're made for firewalls.   Should hold up longer than red RTV, I'd think, which seems to be very common for plugging firewall holes.

Edited October 14, 2019 by EricJ

[Skates97]

9 minutes ago, jetdriven said:

ThOse  look pretty slick with but the aluminum melts quickly,  not really firewall standard 

The description says they are for the firewall and was what my AP/IA had me buy for him to complete the install. If it is getting hot enough at the firewall for that to melt it is going to be a really bad day.

 

[ragedracer1977]

3 hours ago, jetdriven said:

ThOse  look pretty slick with but the aluminum melts quickly,  not really firewall standard 

My whole engine is made of aluminum.  Same as basically my whole airplane.  If an aluminum cable clamp is getting hot enough to melt on the firewall.... Well, it's a really bad day

[jetdriven]

The firewall is stainless steel.  It’s designed to last against a direct flame for 20 minutes.  Putting holes and aluminum fittings in it, compromises it. Some of those aluminum fittings melt in one minute. 

[N201MKTurbo]

43 minutes ago, jetdriven said:

The firewall is stainless steel.  It’s designed to last against a direct flame for 20 minutes.  Putting holes and aluminum fittings in it, compromises it. Some of those aluminum fittings melt in one minute. 

What you say is true, but my 201 has a giant aluminum cannon plug with a plastic pin holder. 

I wonder how long it would take to burn through that? 

[jetdriven]

The factory wrapped it with fire sleeve and tied the end down with safety wire.  They did a lot of things back in the day.  Olde Mooney’s like mine have a mechanical oil pressure and fuel pressure gauge with the hose behind the panel. I did convert it to the electric oil pressure gauge and rid myself of that line. 
 

A firewall is for safety.  It could be improved upon, yes, but adding holes and non-steel fittings compromises it.  The previous installation of an engine monitor used a rubber grommet and some red permatex silicone.  The new JPi I’m installing runs the wire through a steel eyeball fitting. 

[ArtVandelay]

What you say is true, but my 201 has a giant aluminum cannon plug with a plastic pin holder. 

I wonder how long it would take to burn through that? 

I got to believe the fuel hoses have melted, the fiberglass cowl is in flames, and by then the breaching the firewall through a small hose will be the least of my concerns.

[N201MKTurbo]

Just now, ArtVandelay said:

I got to believe the fuel hoses have melted, the fiberglass cowl is in flames, and breaching the firewall through a small hose will be the least of my concerns.

The cowl will not burn, the antimony trioxide works well. 10 years ago when I was rebuilding my cowl I laid up a test piece and attacked it with a propane torch. It would not burn, it just turned into a carbon fiberglass char.

[Skates97]

"We now return to your regularly scheduled programming..."

If someone has a pic of how/where the mixture cable is mounted I would love to see it. The parts catalog that I have doesn't show anything there.

[EricJ]

2 hours ago, Skates97 said:

"We now return to your regularly scheduled programming..."

If someone has a pic of how/where the mixture cable is mounted I would love to see it. The parts catalog that I have doesn't show anything there.

 

Is 17 not it?

Edit:   Oh, duh, the rest of it...

Edited October 14, 2019 by EricJ

[jetdriven]

3 hours ago, ArtVandelay said:

I got to believe the fuel hoses have melted, the fiberglass cowl is in flames, and by then the breaching the firewall through a small hose will be the least of my concerns.

Fire sleeved hoses meet the same spec.  Cowling doesn’t matter, the airplane can fly with a meting cowl.   But any breach in the firewall with fresh holes cause by an unapproved part installation can be the reason the cabin fills with smoke and noxious gases, which leads to incapacitation and a crash. You really don’t have much time anyway. I can’t believe the pushback and excuses in getting on this. 

[EricJ]

31 minutes ago, jetdriven said:

Fire sleeved hoses meet the same spec.  Cowling doesn’t matter, the airplane can fly with a meting cowl.   But any breach in the firewall with fresh holes cause by an unapproved part installation can be the reason the cabin fills with smoke and noxious gases, which leads to incapacitation and a crash. You really don’t have much time anyway. I can’t believe the pushback and excuses in getting on this. 

From what I can gather firesleeve is good to 500F continuous, and SCAT is similar.   Even the lowest temp aluminum alloys don't melt until about 900F, and some alloys and pure aluminum are as high as ~1220F.  Given that there's some decent mass to that part (i.e., it's not foil or thin material) and it's plugged into a stainless heatsink, I'm having difficulty seeing why the part in question would be an issue, given the general number of other holes in the firewall and the stuff that's usually connected to them.   As others have mentioned, I think if you get to the point where that thing melts and creates an issue it's unlikely to add significantly to your problems at hand.

But if you really don't like the aluminum one, you can use a plain Bowden clamp:

https://www.aircraftspruce.com/catalog/appages/bowdenclamp.php

Or put some red rtv on it, supposedly good to 600F, better than firesleeve!

Just my dos centavos, ymmv. 

Edited October 14, 2019 by EricJ