Vent ports on M20K footwell

[HawkGT]

Are the three ports on the passenger side footwell vent lines in the below pic?  What do they vent?  I dont see them on the IPC.  Scanning the internet I see some M20Ks have these and some don't.  Thanks!

 

Jason

[1980Mooney]

That is all part of your Mod Works Thunderbird 261 conversion.  You posted the STC on MS back in the spring.  It was modified with a Garrett turbocharger (you can see Garrett in your pic).  And your other STC matches a TurboPlus intercooler but the ducting looks different.

1980 Mooney M20K 231 for sale (hangar67.com)

 

[Jim F]

My 1981 M20K has them and i am stock.  I would guess they are for fuel flow setup and adjustment so you can close the door or not feed fuel line through the wing window.  make sure you have caps on one side or you have a CO leak.

[HawkGT]

5 hours ago, 1980Mooney said:

That is all part of your Mod Works Thunderbird 261 conversion.  You posted the STC on MS back in the spring.  It was modified with a Garrett turbocharger (you can see Garrett in your pic).  And your other STC matches a TurboPlus intercooler but the ducting looks different.

1980 Mooney M20K 231 for sale (hangar67.com)

 

I understand two STC have been installed in my airplane but I dont understand the purpose of the three ports in the footwell. The Turbo plus web page has pictures with and without those ports.  Are they vents/drains?  Are they bulkhead connections for test gauges, doesnt look like it?  Are you saying it was part of the TurboPlus STC that was abandoned when the ModWorks conversion was done?They appeared to be plugged with RTV and before I do anything I want to understand what they are for.  Thanks!

PS- yes the baffle/cowl seals look like trash and I plan to replace them asap.

[Fly Boomer]

6 hours ago, Jim F said:

My 1981 M20K has them and i am stock.  I would guess they are for fuel flow setup and adjustment so you can close the door or not feed fuel line through the wing window.  make sure you have caps on one side or you have a CO leak.

I read somewhere (probably MS) that your explanation is exactly what they are.  I thought they only showed up on later M20Ks, but that's clearly not correct.

[1980Mooney]

7 hours ago, Jim F said:

My 1981 M20K has them and i am stock.  I would guess they are for fuel flow setup and adjustment so you can close the door or not feed fuel line through the wing window.  make sure you have caps on one side or you have a CO leak.

 

2 hours ago, HawkGT said:

I understand two STC have been installed in my airplane but I dont understand the purpose of the three ports in the footwell. The Turbo plus web page has pictures with and without those ports.  Are they vents/drains?  Are they bulkhead connections for test gauges, doesnt look like it?  Are you saying it was part of the TurboPlus STC that was abandoned when the ModWorks conversion was done?They appeared to be plugged with RTV and before I do anything I want to understand what they are for.  Thanks!

According to the Service Manual early K's (SN 25-0247 to 25-0835) had the 3 holes in the firewall footwell to route hoses for test gauges using an adapter (050006-501)  Later K's had an access cover.  So it was not modified as a part of the Mod Squad 261 Thunderbird modification. - but they probably needed to use the access to set up the engine after the modification.

It is odd that the test gauge access starts with 25-0247. I wonder how they ran the test gauges before 25-0247 ... Perhaps Mod Works 262 and Mod Squad 261 would just punch holes in the firewall footwell on the earlier models. 

Yours is 25-0280.  I don't think there is any reason to do anything with them - just make sure they are sealed well.

Edited October 24, 2022 by 1980Mooney

[kortopates]

I think Mooney dropped the firewall fittings non-sense because there is absolutely no reason to run the gauges into the cockpit.  

If that's a recent pic @HawkGT watch out for the unsecured air filter clasp. When secured, those should be safety wired too.

[1980Mooney]

Here is a picture of the right footwell on M20K 25-0762 which had a Mod Works 262 conversion.  The fittings look like they are piped and flanged ready to connect to gauge hoses.  I wonder if they protrude the same way inside the footwell.

BTW @HawkGT - the footwells on your plane in the pic above look shinier than the soft sheen of the aluminum on the firewall.  They don't seem to match the original firewall material.  They look like they might have been changed by Mod Works with a different material (stainless steel?) and shape/size vs the standard K.

 

[HawkGT]

13 hours ago, 1980Mooney said:

Here is a picture of the right footwell on M20K 25-0762 which had a Mod Works 262 conversion.  The fittings look like they are piped and flanged ready to connect to gauge hoses.  I wonder if they protrude the same way inside the footwell.

BTW @HawkGT - the footwells on your plane in the pic above look shinier than the soft sheen of the aluminum on the firewall.  They don't seem to match the original firewall material.  They look like they might have been changed by Mod Works with a different material (stainless steel?) and shape/size vs the standard K.

 

 

I also noticed that mine is polished versus most of the other pictures I have seen which are not.  No clue why or when this was done.  I agree it's likely when the -MB engine was added.

Your picture clearly shows more threads sticking out on the engine side for the female adapter to connect.  That's part of what was confusing me on mine as there wasn't enough sticking out to connect gauges or lines.  Likely just how they are adjusted/installed.  Thanks for all the help!