Cowl fit issues

[1labelloj]

I have the horizontal (top and bottom) type cowl. I am having conflicts on top with the oil cooler ( even after I took off the top front flange edge), and with the aeroinjector air filter on the bottom. The cowl is touching in both places.

What are my options? What have others done?

[WaiexN143NM]

Hi guy,
Are you building a onex, waiex, sonex, or xenos? Also which engine?

WaiexN143NM
Michael

[jeff0196]

I'm guessing you are building with the AeroVee by the way you are describing your top mount cooler. I had/have the same problem with my vertical split cowl. I looked at the factory planes during Airventure after noting this issue on mine, and noticed that the props on them are not really centered in cowl on the ones that I saw. So the engine sits lower in the cowling. This may be intentional, or this may be because the motor mounts have sagged on them. With the prop lower, it does give a little step between the prop and the cowl, not smooth like mine. Either way, with the engine lower in the cowl, the oil coolers on the factory planes seemed to clear the cowl. I would have moved the prop lower in my cowling, except for the trimming was already done past the point that it would have made sense to do it that way. So instead I did something that I saw in a factory LSA with a rotax engine. The place where they mounted the radiator made two corners of hit contact and rub on their fiberglass cowl. They litterally just smeared red RTV on the fiberglass in the area where the cowl was hitting. I found on mine that it is fairly easy to put on an extra piece of 3x 3/32 fiber reinforced silicone baffle seal and fold it forward to be the cushion between the cowl and the oil cooler. Time will tell if that was a bone headed idea or not. Not sure about the air filter problem you are having, cannot quite picture it in my head, but I know those tubes can usually be persuaded into a better position with a little pressure.

[dtwolcott]

Good Morning
I am not sure what problem you are having with the air filter and how it is creating a problem on top but I did have a problem of the two front air filter bolts touching the lower cowling. To remedy this problem I reversed the direction of the front two bolts so the nut was on the top. This gave me a little extra room in the bottom cowling. I doubt that this extra room will translate to a little extra room on the top though.

[Darick]

Yes I did the same thing concerning the bolts. Additionally I cut off some of the intake manifold where it attaches to the carb with the flexible tubing.

[Bryan Cotton]

All,
My cowl is not very thick compared to the windscreen. I can leave it as is, lay up extra glass underneath, or put something like weatherstripping in there. Anybody have ideas, experience, or opinions?

[SonexN76ET]

Bryan,

Under my upper cowling where it abuts the windscreen, I used 1/8 silicon chaff seal from Aircraft Spruce. That helped to even up the thickness with the windscreen. I have also considered putting an extra layer of fiberglass on the inside lip of the cowling there too.

Jake

[n502pd]

Bryan, and all, I have the exact same issue with the windscreen thickness and the cowl thickness. I plan to put fiberglass pads at the appropriate screw locations, thick enough to raise the cowl to be flush with the windscreen. But, I want to get a bit more flight time before I do so. Its pretty cold even here in Texas this winter and fiberglass projects will wait for warmth and flight time. In the mean time, I am using square patches of baffle seal and/or very small OH-rings to do a reasonable job.The rubber does compress some so they are not perfect,

I have AeroVee with bottom cooler, and have the same problem with touching the bottom cowl with the air filter plate. I chamferd the leading edge of the plate to make it parallel with the fiberglass rub spot, and then put a 2 in piece of .025 Al centered over the rub spot, and riveted it on the RH half to hang over the hinge with a hump to cover the LH half of the rub spot. (Hope that makes sense!). So, with the normal oil from wherever, when the filter plate does rub, its against aluminum and is lubricated...so it don't squeak!!! And, my prop isn't centered anymore. I estimate it has dropped about 1/4 inch at 12.7 hrs TT. As long as everything else seems fine...it is...I will probably change the mounts at each condition inspection.

[builderflyer]

Bryan,

I glued a strip of cloth chafe tape (similar to Aircraft Spruce pn 09-31800, mil-c-5649) to the firewall flange. It's now been there for 13 years of flying and is holding up well. I also applied it on top of the fuel filler box to seal that area to the cowling as well.

Happy building,

Art,,,,,,,,,,,,,,,,,,,,,,,,,,,Sonex taildragger #95,,,,,,,,,,,,,,,,,,,,,,,,Jab 3300 #261

[LarryEWaiex121]

Ditto Art,

My Waiex has anti-chafe tape on the entire metal area under the cowl on the top former. Fueling area included. Its been there now for 6 1/2 years and almost 600 hours.
My poor cowl has a number of issues that will require its complete rebuild or replacement at some point in the future. I have a couple area that have "stared" or cracked the paint and gel coat. Mostly due to mis-handling on the part of the owner. :(
Additionally, I have wear spots on the front of the cowl where my oil pump housing rubs on the cowl at times. I fixed my sagging mounts with aluminum washers behind the lower rubbers. Unfortunately, that pushes the housing into the cowl. Its a never ending game.
One of my cowl tunnels begain to crack out on a back corner. Re-inforcement with aluminum sheet and some rivets fixed that one.
Yup, she has a few more parts than she started life with. Doesn't matter because my Waiex has taken me places far and wide and I love her in spite of her beauty marks.

Larry
Waiex121YX, Camit 3300, Dynon Skyview