PA-22 Chin scoop baffle seal

[walt.buskey]

Oops... already ordered it, early this morning. Don't know what the deal is for returning, etc., but it does gall me to a certain extent to have to buy another $200 part....

So you're saying you don't have that scoop installed now? (Any issues?)

[Subsonic]

I don't have that scoop installed. It wouldn't fit properly. No issues with the way my TP runs. I have a 58" prop on it and it will easily exceed redline of 2700 rpm if I let it running flat out at sea level. I've flown at 1820 pounds gross over the top of Lake Tahoe and Half Dome at 12,600' and still had climbing capability if I needed it. I'm wondering if some Tri-Pacers had the scoop as original equipment and some did Not. ?? I know my intake does not line up with the front strut and the scoop is constructed as if everything is in line with NO offset. Now that I'm thinking about it, it may be due to angular offset of the carb due to tolerances. I didn't try to loosen the carb bolts and rotate the carb on its vertical bore axis, but that's all I can think of that may cause the misalignment. That is, if it's really supposed to be in there. My PA22 is a 1956. What year is yours?

[andya]

Oops... already ordered it, early this morning. Don't know what the deal is for returning, etc., but it does gall me to a certain extent to have to buy another $200 part....

So you're saying you don't have that scoop installed now? (Any issues?)

Walt, I have been able to return items to Univair, I told them my part for whatever reason didn't fit.

[walt.buskey]

Subsonic -- yes, mine's also '56, SN 3868.

1) When I get Univair's, I'll see how it fits. If it's OK, I'll be in touch to see about buying yours and sending Univair's back.
2) If it has the same alignment issues, I'll leave it off and again contact Univair about a return. (Thanks, Andy.)

I'm not aware of any cooling issues the PO had with it in the 6 years and several hundred hrs he flew it, but I'm really trying to make this plane right.

Walt

[Glen Geller]

My guess is >75% of the Tri-Pacers out there do not have the air inlet scoop.
And it probably has a very minor impact on performance.
Most IA's are not aware of it's existence and would not notice if it's there or not.
I went ten years without one, but about six years ago I bought NOS and had to tinker to get it to fit right (reverse the overlaps, replace round rivets with flat and install from inside out, etc., and snappy black paint finish.)
Making a strip with rivnuts to clamp it to aft face of airbox flange is a good trick: install bolts from inside Brackett housing, thru airbox flange, thru scoop flange, to nuts with big washers or a strip with rivnuts. Because its hard to reach thru the cluster and hold all the parts and nuts/washers.
It will not work if you try to sandwich it between the Brackett filter housing and fwd face of airbox.


Here's some comments and pics from that "other" Shortwing group:
https://forum.shortwingpiperclub.org...ffles-and-such

[walt.buskey]

Thanks, Glen -- good pics there! I never thought to check with Precision -- I've bought several parts from them in the past.

Guess I'm like that poster on SWPC: I'm also not convinced it makes a huge difference, but I'm just trying to do the right thing to my poor old bird.... which has suffered from quite a bit of "Well, that's good enough for an old airplane-itis" over the years.

[Subsonic]

It will not work if you try to sandwich it between the Brackett filter housing and fwd face of airbox.

Ok...I tried to sandwich it. I may have to try it again.

[walt.buskey]

So I need to trim my aluminum strip back a half inch or so, but here's what my lower baffle looks like so far. I'll use bucked rivets to attach... and this is after spending an hour+ removing old paint, tapping bumps down, sanding and re-painting.... amazing what some clean-up & paint will do. (Nose gear is next!!)

Using some McFarlane "Cowl-Saver" material. Will test fit, then decide if I need small pieces on the sides or not; there's not a lot of open area below the sides on mine anyway, and only about 1" of space beneath the straight horizontal center section.

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[andya]

nice work Walt

[walt.buskey]

Thank you! It sure does look a lot better, and I think I'm getting the hang of my ATS 3X rivet gun (at least until I screw it up again...). Not too shabby, if I do say so. With all the things I've repaired over the years with rivets, I should have had one of those YEARS ago. (And who among us can resist "Just one more tool, sweetie!")

Test fit the piece, and I will add two small sections of baffle seal to the short side sections -- there's enough of a gap there that I know I can improve it.

BTW -- I have this "mystery scoop" inside my chin cowl; anybody know what it's supposed to do? I haven't been able to find anything about it in my parts book.

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