Vent tube position?

[Joe Larussa]

Does the angle of this vent tube look correct to you? Seems to be interfering with my cowl flap closing all the way.

[PT20J]

Do you have the flat left cowl flap or the curved one that's shaped like the right one? My 1978 J had the flat flap and if I recall, the flap did touch the breather tube. My 1994 J has the curved flap and there is plenty of clearance. With a flat flap, you might adjust it to have a 1/2" or so gap when closed. Bob Kromer claims that this actually creates slightly less drag.

Skip

[Joe Larussa]

15 minutes ago, PT20J said:

Do you have the flat left cowl flap or the curved one that's shaped like the right one? My 1978 J had the flat flap and if I recall, the flap did touch the breather tube. My 1994 J has the curved flap and there is plenty of clearance. With a flat flap, you might adjust it to have a 1/2" or so gap when closed. Bob Kromer claims that this actually creates slightly less drag.

Skip

Good question. I’m not sure. It’s a 77 M20j 201.

[EricJ]

10 minutes ago, Joe Larussa said:

Good question. I’m not sure. It’s a 77 M20j 201.

Even in 77 it seems that some of them may have gotten the flat cowl flap and some with the bend.    Mine is an early 77 (sn 24-0077) and it has the flat flap.   I found this recent pic when I was measuring the lengths of the actuator rods that shows how my vent tube is attached and pointed.   It points straight toward the tail of the airplane, but it appears to be mounted to the middle screw rather than outboard like yours is shown.    My fuel pump vent (the rubber line) was out of the way at the time, but only needs to be generally pointed to where it'll drain.

[Joe Larussa]

39 minutes ago, EricJ said:

Even in 77 it seems that some of them may have gotten the flat cowl flap and some with the bend.    Mine is an early 77 (sn 24-0077) and it has the flat flap.   I found this recent pic when I was measuring the lengths of the actuator rods that shows how my vent tube is attached and pointed.   It points straight toward the tail of the airplane, but it appears to be mounted to the middle screw rather than outboard like yours is shown.    My fuel pump vent (the rubber line) was out of the way at the time, but only needs to be generally pointed to where it'll drain.

Does it matter which direction the hole in the breather tube faces? 

[cnoe]

Your upper adel clamp may need to be rotated 180 degrees. Mine also points straight back as shown. ‘78 J. The vent hole should align properly if the tube points rearward. 
 

[201Steve]

77J. SN 141

[carusoam]

The case vent has some specific dimensions that are known to work….

Then there are issues that are known not to work….

Position and length of the vent tube, and location and orientation of the whistle hole get covered around here often…

Doc probably posts the MM drawing often…

Great pics everyone!

Go MS!

Best regards,

-a-

[EricJ]

I found a much better pic of my installation, including the ice hole that was added (not required).   Mine fits under a flat cowl flap.

[cnoe]

Following up…

Eric’s installation has the lower bolt further inboard one hole with the adel clamps rotated opposite of mine. That would likely put the tube ~1” further towards the center which might help your clearance.

I can’t state how it left the factory 40+ years ago and my manual doesn’t contain an accurate depiction but it appears either setup above would work. 
 

FWIW I too have the flat cowl flap on the port side.

CNoe
 

[Joe Larussa]

You guy's rock! I knew something on mine wasn't right.

[Joe Larussa]

And fixed! Looks like I’m a flat flapper.

[cnoe]

Joe, not to nitpick but if not already done, you may want to tighten up that jam-nut at the top of your cowl-flap adjustment rod. I can't believe Clarence didn't mention that already!

CNoe

[Joe Larussa]

1 hour ago, cnoe said:

Joe, not to nitpick but if not already done, you may want to tighten up that jam-nut at the top of your cowl-flap adjustment rod. I can't believe Clarence didn't mention that already!

CNoe

Lol! I appreciate the extra eyes. I readjusted the cowl flap after fixing the vent tube.

[Mcstealth]

On 7/19/2022 at 8:49 AM, Joe Larussa said:

And fixed! Looks like I’m a flat flapper.

I had an old girlfriend like that

Not @Marauder though.