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  #41  
Old 03-13-2019, 06:15 AM
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DanH DanH is offline
 
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Scott, later in the process you'll be adding baffle sealing rubber. If you expect it to lay and seal tightly, now is the time to adjust the relationship between the cowl and the baffle tin.

For example, across the lower segment of the opening, the rubber will be fastened to the underside of the fiberglass, and extend rearward over the top of the aluminum, just in front of the filter opening. To put the cowl on there must be enough clearance for the rubber flap to be popped into place, past the aluminum. So, the underside of the glass should be about an 1/8" above the aluminum after the engine mount has settled a little, and the horizontal gap should be about 1/2". To gain the gap you can shorten the aluminum or the fiberglass. I usually say shorten the glass, because doing so moves the ramp forward in the upper cowl.

The outboard baffle wall should probably be moved inboard a 1/4" or so, again to get that optimum 1/8" between the backside of the fiberglass and the face of the aluminum.

Please excuse me if it was just an interim photo with the adjustments still to come. The point is that it is real important to get baffle fit correct at this point in the build, or you'll have trouble later.
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  #42  
Old 03-13-2019, 06:55 AM
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Quote:
Originally Posted by Paul K View Post
I started out doing what you did to make it fit but was so totally turned off by the results that I tossed it in the junk and built one from scratch.

Beautiful work Paul.

It's generally easier to start from scratch with a foam form, and the results are better.
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Last edited by DanH : 03-13-2019 at 06:59 AM.
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  #43  
Old 03-13-2019, 08:53 AM
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On X it is for structural support to tie it all together. I am aware of a decrease in the perceived inlet area from the X portion. Do note that it is above the filter with a gap, permitting full air flow to the filter. Also photo is in progress. About 1/4 ? removed from cowl and rubber attached as well as a taper in corner for cover to match cowl curve. Rubber fits great this side, right had a wrinkle that needed a slit.
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  #44  
Old 03-13-2019, 09:43 AM
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Default Mine fit

IMG_8523 by Ed Fleming, on Flickr
IMG_9039 by Ed Fleming, on Flickr

IO-360-M1B Supplied by Vans.

Note the part number. The-2 would suggest that there may be up to 3 iterations of this part. Mine was delivered late 2017.
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  #45  
Old 03-13-2019, 05:54 PM
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Quote:
Originally Posted by Z-EDD View Post
IMG_8523

IO-360-M1B Supplied by Vans.

Note the part number. The-2 would suggest that there may be up to 3 iterations of this part. Mine was delivered late 2017.
This is how mine fits as well, more or less, and I also have a -2 snorkel and same engine. It seems that the outside edge of about 1 inch too far outside (same with the inside edge); I would expect that the duct would fit nicely along the flat part of the cowl. This one rides up on the outside curve of the inlet, and comes close to the edge of the horizontal ramp and to the vertical part of the baffle just inside the right edge of the inlet. No real room for a conical piece here help seal the lower cowl rubber, or nice edge distances otherwise (See DanH's earlier response)

Is this what "normal" looks like? Seems consistent with Ed's:

Front view:



Side view:

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Last edited by wjb : 03-13-2019 at 06:04 PM.
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  #46  
Old 03-14-2019, 12:41 AM
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Quote:
Originally Posted by wjb View Post
This is how mine fits as well, more or less, and I also have a -2 snorkel and same engine. It seems that the outside edge of about 1 inch too far outside (same with the inside edge); I would expect that the duct would fit nicely along the flat part of the cowl. This one rides up on the outside curve of the inlet, and comes close to the edge of the horizontal ramp and to the vertical part of the baffle just inside the right edge of the inlet. No real room for a conical piece here help seal the lower cowl rubber, or nice edge distances otherwise (See DanH's earlier response)

Is this what "normal" looks like? Seems consistent with Ed's:

Front view:



Side view:

Just to be clear Bill, I am happy with the position of my snorkel. I don't think it would have been possible to move it any further inboard. Note my case baffle seems further outboard than yours, and there is only just room for the forward screw. A conical gusset may be possible, slightly covering the corner of the filter, but I plan on fitting the baffle seals first to see how things work out.

In my experience the filter is just slightly too big for the inlet ramp, requiring modification of the baffles in all directions, incuding fore and aft, but that is certainly easier than major surgery on the snorkel.

I do wonder though what part number the OP's snorkel had, and anyone else who had to modify the snorkel?
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  #47  
Old 03-14-2019, 06:26 AM
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First get the cowl completely fitted and detailed. Hinges, Skybolts, screws, seam gaps, inlet spigots, everything.

Then get the aluminum dead on. There is no reason to believe the ramps and walls will be in the right places if clecoed together right out of the box, just like snorkels don't always fit right out of the box.

Then do whatever is needed to the snorkel, which includes just fabricating one which fits your particular combination of parts.

We're not talking wing spars here. Forget part numbers. Build something.
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  #48  
Old 03-29-2019, 07:46 PM
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Default Harley style baffles

Finished up baffles after snorkel fit- besides the inlet adaptations I used backing plates with nut plates to seal all rubber to baffle aluminum for no seepage gaps. I struggled with my 9 to seal bottom edges when attached with just rivets. Then painted high temperature flat black and baked in oven. With the chrome valve covers and stainless screws I like the Harley biker look. Also reinforced the oil cooler mount to rear and side and added a oil cooler shutter.


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  #49  
Old 03-30-2019, 01:29 PM
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To Scott especially, but everyone really --

On the intake flow into the filter, you really want to avoid sharp edges on plates that the flow has to go over as it turns down into the filter. Ideally you would want to have a radius lip all around the perimeter of the filter. This is difficult because the filter is using almost all the available space. But the big filter isn't helping much if the flow is restricted getting into it.

When flow goes over a sharp edge, it separates. The best-possible result is that the flow just goes straight, as if the sharp edged plate was literally a stencil for the allowed flow area. In reality, the effective flow area is reduced even further beyond just the 'stencil' projection. Do a google-search on 'vena contracta'.

The installation that Paul K posted in the Picasa gallery is better, with the doubler/cover plate with the bend-down transition edges. Even better would be to roll those edges in a circular radius down, rather than just an angle bend.

It would also be OK/helpful if you can install semi-circular lip radius around the filter perimeter that projects above the plane of the baffle and filter. Any smooth radius transition is better than sharp edges.
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  #50  
Old 03-30-2019, 02:15 PM
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Quote:
Originally Posted by scsmith View Post

On the intake flow into the filter, you really want to avoid sharp edges on plates that the flow has to go over as it turns down into the filter. Ideally you would want to have a radius lip all around the perimeter of the filter .
Noted, I don't disagree but lot of things require compromises when building. We will see by my empirical testing in flight. My cover installation was to tie the snorkel, baffle assembly together as a solid unit with too little real estate to fit the filter. The x gave it the strength for a thin sheet to conform to the complex shape without buckling. I agree a sharp edge will not promote laminar flow but will act as a weir causing some turbulence. The question is does that cause any effect to the engine's needed airflow. In flight the inlet is pressurized so worse case is wide open throttle at redline during initial climb out. I believe there must be substantial excess flow capacity and area since the same filter is used for the 360 and 540 with two more cylinders by Vans web site.
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