N247BR

Engine Cowling - Engine Air Box

The original engine configuration included the AeroSance FADEC system.  The FADEC was an electronic ignition and port fuel injection system.  The throttle body for the FADEC included dual sensors for Manifold Pressure and Air Temperature.  The sensors were mounted vertically above the throttle air control which resulted in a 6 1/2 inch high throttle, much higher than the standard height.  I looked at multiple different options for an filtered air box but everything was too deep and too big.  I finally found the custom made airbox seen below.  It was the smallest filtered box with bypass air inlet that would come close to working.  Still, the overall combination caused me a lot of problems.
	The filter air box raised the filter up so that the bottom was not lower than the overall unit.  Seem like a workable solution when I ordered it.
I had already installed the NACA air inlet which was provided with the kit.  I really liked the look of the NACA inlet and wante to keep it.  BUT...isn't there always a BUT?  But the I tried to install the lower cowling it was obvious that it wasn't going to go as planned.  The bottom of the air box was lower than the lowest point of the cowling and extended well into the opening provided by the NACA inlet.
In addition to extending forward beyond the inlet, it required me to cut out the bottom.  Even cutting the bottom wasn't going to clear the air box.  It was obvious that I was going to need to totally redesign the air inlet.
I started by removing a large section of the cowling and providing a glass lip to be used for forming the new opening.  Once the opening had bee cut it was clear that the air box and filter were offset by more than an inch to one side.  It also became clear to me that mounting the lower cowling by myself was going to be a royal pain in the kiester.
I had been trying to decide where and how I was going to take off heater air for the exhaust system heating system.  Seeing the offset I came up with the idea of adding a heater air intake on the side of the air box.  The above photos show the offset and the fabricated air inlet that I fabricated from some sheet aluminum.
The combined carb air and heater air box is shown above.  The next problem to be solved is how to channel the air into the air box and to mold that into the cowling.  I also wanted to find a way help me hold the cowling in place while I made the connections at the back of the cowling.
My solution was to create a flexable sleve that would attach to the air box and would allow a molded inlet to be inserted and form an airtight inlet.  I used baffle material and aluminum angle to build the inlet sleve.  Looks like something out of a warped mind but it actually works.  It allows me to slide the cowling into the sleve and make the connections at the rear of the cowling.
After creating the sleve which was oversized to start and trimmed after I had worked with it some.  I used foam to construct a plug to fit on the inside of the sleve.  I shaped the foam to provide an opening to capture the air and route it into the airbox.  I knew the shape that I wanted to obtain and I filed, sanded the foam until I obtain the shape I was looking for.
Once I had obtained the shape and size that I wanted, I took off another 1/8 inch from the foam plug.  I covered the plug with the standard for all purposes, duct tape.  The taped over plug was then wrapped with three layers of fiberglass.  Once cured, I trimmed the resulting duct to the final shape shown above.  The remainder of the process for redesigning the cowling and the air inlet will be described in another section.
Hell, if it were simple and easy anyone could do it.  By the time I got to the point of seeing an end to this project so much time had passed that I ended up having to redo so many things and the airbox and cowling appeared to be another example.  Aerosance had been bought by Continental and the FADEC system was killed by neglect.  I don't know why they bought them but they dropped support years before and I was stuck with an orphan.  I made the HARD decision to give up on the FADEC and go with another choice.  The choice...FLYEFII Electronic Ignition and Fuel Injection System.  The OLD FADEC throttle was out and the FLYEFII throttle body was in.
So what was the difference?  The FLYEFII throttle body was more than two inches shorter.  I actually had to add a spacer to get back to the 6 1/2 inches.  The throttle valve was on the opposite side and my bracket for the throttle cables was no longer workable.  I had to redo everything.  These photos show the noew installed throttle body with the throttle cable bracket that I hand made.
Hours and hours of time and redesign could have been saved if I had made the change years before and gotten rid of the FADEC.  I just couldn't justify it at the time because it looked like the FADEC was going to be supported.  Now, even though I could have raised the airbox up a couple inches it would have required me to totally redesign everything yet again.  NO WAY I am doing that again so love it or hate it, I modified the throttle to fit the cowling.