Baffle Seal Help

I am just about through with the baffles on my IO-320/9A.
My problem area, not exactly sure how to cover, is the spot on the front baffle.
The area where the baffle, after going across the front of the engine,
turns back toward the front and the cowl air inlets.
How do you seal the gap between the top of air inlet on top cowl and the center
front baffle. The air inlet ramps on the top cowl are very close.
A nudge on what to do here greatly appreciated. Plans don't really give
a good explanation, at least to my warped eyes and brain.

On my 7 I made 4 pieces of baffle
With the cowling in place I marked both inlet cowl scoops on to the metal that goes up the sides outside the starter ring

Then I added the baffle material from where the rear of the fiberglass cowling splits around the prop shaft back to the area where it would overlap the baffling material on behind the starter ring. I mounted it down 3/4 inch from the inlet scoop line and ran it up diagonally till it overlapped the back starter ring baffle

Starter ring baffle
I ran two separate pieces on each side of the baffle ring back metal each one ran up to the metal baffle support which I notched out of the rubber so these two rubber baffle could overlap by 3/4 inch. I mounted mine on the aft side of the metal baffle.. I have seen them mounted both ways but for the rubber to bend backwards was just more natural


I put the cowling back on and made sure that the side rubber baffle would be on the outside of the back ring baffling... Like you stated I only have about a 1/4 inch max between the inlet scoops and the metal baffling around the prop extension. But with a little marking I got the dog ears to over lap so the side rubber would push up on the back rubber....
I am on a trip flying and do not have access to any pictures at this time.

Jack

I had to extend the upper fiberglass ramps inboard several inches so the baffle material had something to lay/push against. I used blocks of blue foam glued in place, I glassed the entire side as well just because. Pic shows the extra glass, again the extra glass perpendicular to the inlet ramp isn't necessary.


Line drawn on the outboard ramp shows the position of the metal baffling. If I would have originally positioned the ramps further inboard I probably wouldn't have had to the the glassing on the inboard side.


Baffle material.

Not a -9 but maybe these will help

I am not familiar with exactly what the -9 does in this area, but here's a few shots of what I ended up doing on my -8. I agree that the plans give very little guidance in this area, particularly as to how to deal with the ramps.

To start with I could not visualize a way to get the baffles to seal against the ramps, so I decided to take the baffles all the way to the cowl. To do this I cut away portions of the ramps both at the rear, and at the front where it joins the inlet. Only the rear has been cut in this photo...



I then used card stock to make templates. It takes a while to visualize what needs to happen. Make sure you get the laps the right way. Clecos won't fit so I held them in place with the 2 leg style paper fasteners.

When I was satisfied, I used the paper templates to lay out the patterns on the baffle material. There's not much extra so lay them all out before you start cutting...



This is what it looked like when I installed the baffles...





It's a bit of a fiddle to tuck them up in place when you install the cowl, but once you get used to it it's no big deal. Seems to seal well...

Hope this helps...

Thanks But Still Not Sure

The rubber on the outside baffles, when it get near the front by the
upper cowl air ramps...is it supposed to layover and seal against
the air ramp?
The middle front baffle...the rubber on the two sections that turn
toward the front of the cowl...does that rubber lay and seal against
the air ramp there too.
Man I just can't get this in my head how to seal off the two areas.
ANY explanation for a dummy would be super appreciated.

Bayou Bert said:

The rubber on the outside baffles, when it get near the front by the
upper cowl air ramps...is it supposed to layover and seal against
the air ramp?
The middle front baffle...the rubber on the two sections that turn
toward the front of the cowl...does that rubber lay and seal against
the air ramp there too.
Man I just can't get this in my head how to seal off the two areas.
ANY explanation for a dummy would be super appreciated.

Click to expand...

Yes.
The baffle material on the engine baffles need to curve into the engine so the incoming air can push them into the top of the cowl. The sides and bottom of the cowl air inlets are sealed with the baffle material that is attached to the lower cowl inlet.

Thanks Andy But

At the front, both on the sides and at the center......
is the rubber supposed to seal by sealing against the two glass
Air ramps on the top cowl or.....
Go beside them and seal against the cowling itself?
My rubber now lays over a part of each air inlet ramp...
Darn I hate being dense

You can build it either way, it may take several tries but use poster board/pop+beer boxes to simulate the baffle material. As long as the incoming air pushing against the baffle material makes a seal and not a leak you're good.

I sealed mine on the air ramps. To help me visualize how to seal these I placed just the top cowl in place over the bare aluminum baffles. I taped a sharpie to a popcicle stick and traced a line where the center metal baffling meets the top cowl and top air ramps. In my case I had to extend the edge of my upper fiberglass ramps inboard so the rubber baffle material had something to push against. Kinda hard to see in the pic but if your imagine an arc from the top inboard corner of the air inlet on the upper cowl and trace along the inboard horizontal edge of the upper inlet ramp where it meets the top cowl, that is where my baffle material is sealing (riveted to the inside edge of metal baffling and curving into the engine and air inlets).

Couple more pics.
If you look close you can see the pice of baffle material that is connected to the lower cowling inlet (just like the plans). There is a little ear (forward most baffle material) the small part tucks in behind the cowl and the larger ear pushes against the upper air inlet ramp. The incoming air pushes the material against the lower metal inlet ramp, sides of the metal inlet ramps, against the top fiberglass inlet ramps, and further back the material is pushed against the upper cowl.

Bert,
I think you are asking the right question.
I have actually seen it done both ways.
I chose to have my inner seals fold over and seal against the ramps and not go beside the ramps and seal against the cowl.

Edit: Andy beat me to it. His last pic shows how how they both fold over toward the inside.

Go On Andy

I sure appreciate you sticking with me on this.
Those show EXACTLY what I needed to see.
The rubber has to be lower on the sides of the center baffle in the
front to match the angle of the air inlet ramp. The rubber on the lower
cowl over laps and is held in place on the vertical by the ring gear by the
062 alum band and on the outside over the ramp then past the opening
into the little area of the outside points of the cowling.
Man oh Man you don't know how much I appreciate the pics.
Thank You

Anytime!!!