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Extending intake on a composite cowling

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D_limiter

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I had to put a new motor mount on my light sport, due to finding a broken weld during the annual. When it arrived, we found the that oil cooler mount was pushed back on the engine mount struts about 1" or so (seemingly to avoid an abrasion issue with some hoses). However, that means the side intake tunnel on the cowling for the oil cooler now is about 1" shy of reaching the oil cooler. The plane flies, but oil temps are a bit hot and we have to climb out at a faster airspeed to keep the temps down. I would like to extend the intake to direct all the air to the oil cooler.

What would be an efficient/easy way to do this? With the top half of the cowl off, I can reach in and tape cardboard templates to the vent that would give me the extension I need. Should I just lay carbon over the cardboard? fill the cardboard with foam and put carbon over that then dissolve the foam? Any thoughts welcome before I roll up my sleeves and epoxy myself into a corner.

Cowl is fiberglass with a layer of carbon on the inside, weird as that sounds.
 

Victor Bravo

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I would put something other than cardboard between the intake scoop and the oil cooler.

If you put plastic Saran Wrap over the oil cooler first, you can use oil based clay, sticking it to the intake scoop on one side, leaving a blob between the scoop and the cooler, and leadng it in to the oil cooler.

Then, you can carefully take the cowling off, leaving the plastic wrap stuck to the clay and no longer sticking to the oil cooler.

Once this is done you can sculpt and smooth out the shape of the clay for the best airflow.

Then you can put three or four layers of fiberglass on it all, overlapping the (previously sanded and solvent-wiped) intake scoop by an inch or two.

Then when it's all cured and hard, you can scoop out the clay.
 

Vigilant1

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Would some rubber flashing do the trick? My local Rural King sells rubber that is meant for making/repairing farm conveyor belts, it is sturdy stuff and they sell it by the foot. Or get some stiff weatherstripping rubber. Test whatever you get for heat tolerance. If there's a way to rivet it to your existing duct you could bridge the gap. Going with something pliable like this allows you to get very close to the oil cooler without risk of abrading it.
 

wsimpso1

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I am a fan of sculpting the shape out of foam, finishing with clay and then packing tape. The important thing is getting a smooth shape from existin inlet to the HX that you can encase in composite, including connections with the cowling and HX.

Sounds like a fun project to me
Billski
 

D_limiter

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Thanks for the ideas, everyone. My cardboard suggestion was simply to make a template for the amount of extension I need, but the foam/clay ideas are great. I'l try to get pictures this weekend when I am in the hanger.
 
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