Generator blast tube

[Embmech]

Hi fellas,

 

We just acquired a G-model Mooney and getting things fixed here and there. I seem to be missing a blast tube from the generator to the cowling. The hole on my cowling has a patch riveted over it. Was there a mod or service letter to do this? 

[carusoam]

Welcome aboard Emb...

The generator required it...

If your alternator has a fan attached to the front of it, you probably no longer need the bent tube...

If  not sure, feel free to post a pic...

Are you sure you still have a generator?

PP thoughts only, not a mechanic...

Best regards,

-a-

[Embmech]

Yes sir it is a generator. Just odd that someone would take the time to rivet a plate over the hole in the cowling. The pic inside the cowling isn't all that good but can see a blanking plate installed over it. 

[N201MKTurbo]

So what they did was probably not a bad thing. The front of the generator is in the high pressure side of the baffling and the vent pipe is in the low pressure side of the baffling. If you were to connect the vent pipe to the hole, it would put the front and back of the generator at about the same pressure. This would reduce the cooling flow through the generator.

I wouldn't fix it.

[ragedracer1977]

At least they didn't hook up your generator cooling port to your carb heat discharge like someone did on mine. 

[Prior owner]

The scat from my front cowling is directed to the underside of my engine driven fuel pump. The blast tube on my generator is not attached to anything...there are no provisions on the back of my doghouse for another scat tube either... I am not sure if this was the factory arrangement in 1964. 
Does anyone know?

[47U]

6 minutes ago, PilotCoyote said:

I am not sure if this was the factory arrangement in 1964. 
Does anyone know?

No provision for generator cooling in my ‘63 C.  My ‘62 Cherokee had a 1” blast tube pickup off the front baffle running to the generator.  When I overhauled my generator some 7 years ago...

[Mooney-Shiner]

Seeing this legacy thread, I checked the blast tube connection to my Delco generator and found out that it is missing. After two annuals and one prebuy, we totally missed the fact that this ram port was never connected to the generator on my 67F. 

[47U]

1 hour ago, ukrsindicat@yahoo.com said:

missed the fact that this ram port was never connected

Not being familiar with the F model… is the ram port for generator cooling or engine driven fuel pump cooling?  Your induction ram air goes where the fuel pump cooling air inlet was on earlier C models… just asking the question.   

[Mooney-Shiner]

11 hours ago, 47U said:

Not being familiar with the F model… is the ram port for generator cooling or engine driven fuel pump cooling?  Your induction ram air goes where the fuel pump cooling air inlet was on earlier C models… just asking the question.   

I do have a separate blast SCAT tube going to engine fuel pump, but its on the LH side. No issue there. 

The above posted port is on the RH side.

Edited November 7, 2022 by ukrsindicat@yahoo.com

[carusoam]

Interesting…

The ram air door is in the same place about…where the carbureted M20C has the same round 1” hole for the generator cooling air….

Oddly… the unconnected hole is supply air pressure to the lower half of the cowling… interrupting airflow from top to bottom for cooling cylinders….

 

So…. If you connect the hose, or block the hole… you might notice better CHTs….  

Its a small hole, so don’t expect huge changes…. But, people go out of their way to update seals around alternators and starters for the same issue…

 

PP thoughts only, not a mechanic…

Best regards,

-a-