Lower cowling air intake hose

[isaacpr7]

On my 68C, between the landing light and oil cooler intake, there is small (about 1") round intake hole that has an orange duct connected to it on the inside of the engine compartment. This hose is not connected to anything. I asked a buddy of mine who also owns a Mooney and he says that his aircraft also has the disconnected hose. Does anyone know if this hose is supposed to be connected to something or is this just for getting air into the lower back portion of the engine compartment?

[cbarry]

I believe it's there for cooling purposes. I formerly had an F model on which this type of smaller scat tubing was positioned to cool the engine mounted fuel pump.

[isaacpr7]

I believe it's there for cooling purposes. I formerly had an F model on which this type of smaller scat tubing was positioned to cool the engine mounted fuel pump.

Was it attached to the pump or was it just laying inside the cowling in the general vicinity of the pump?

[mike28w]

My '63 M20C  also had this opening and scat hose......   I have heard three explanations and don't know if any are correct.....

 

Answer #1.  " It's supposed to go all the way back , behind the engine and blow air on the mags".  ( I couldn't find any kind of shrould to direct the air)

 

Answer #2. It's supposed to go to a shroud that surrounded the generator, to help cool it.  ( Mine had already been converted to an alternator, so no shroud)

 

Answer #3.  Supposed to go to some sort of shroud that directs the air to the mechanical fuel pump on the rear of the crankcase.  ( again , I could find no shrould or any other thing to connect it to.)

 

 After having read articles that speak to how the older cowl openings were actually too large and created too high a pressure in the bottom of the cowl anyway......   I simply removed my scat hose and covered the opening with a piece of clear tape.   It's been that way for almost 10 years now with no apparent detrimental effects.

 

  Disclaimer:  I'm not a mechanic and don't know what I'm talking about.  Hopefully someone more knowledgable than I will chime in.     mike

[pirate]

The hose you are describing goes to the Alternator / cooling. At least on my aircraft is does.

[piperpainter]

It should be attached to your generator if you have one. They had a 1" line that went to them to keep them cool during operation. However these days we have alternators and they don't run nearly as hot so the alternators do not require the 1" cooling vent. When I changed from a generator to an alternator I had worked with my mechanic and put a patch on it. Looks much better than with the hole! Hope that helps. 

[orionflt]

It should be attached to your generator if you have one. They had a 1" line that went to them to keep them cool during operation. However these days we have alternators and they don't run nearly as hot so the alternators do not require the 1" cooling vent. When I changed from a generator to an alternator I had worked with my mechanic and put a patch on it. Looks much better than with the hole! Hope that helps.

+1 unless you have a generator or an older style alternator that required cooling you no longer need that tube, I did how ever keep ine attached when I first installed my alternator and had the blast air directed at it. I have since removed it because it was unnessasary duct work just taking up space.

[carusoam]

65C....generator has the matching 1” connection...

-a-

[Shadrach]

IIRC and your cowl is at all like my F the hose you describe is the fresh air inlet for the cabin heat exchanger. Look at the heater shroud and see if the inlet is missing a hose. the Fuel pump blast hose come off the research baffle wall. The generator cooling hose is to the right of the generator.