This is what the cowl looks like installed on someone ELSE'S bird. Again, look carefully at your Goggled Evolution images and the image below, looking carefully at the air inlet under the nose. See the difference? If you are like me, then you may suspect that this installation will be... faster. The inlet is more aligned with the local streamlines around the nose, I think!
OK so here is my cowl. Look below to see how much the lower half of the cowl weighs. I am holding it a few inches off the ground with ONE FINGER. (and this is before the peel-ply is pulled out and the edges trimmed, which will cut the weight down a lot more!)
Now we want to trim off the edges of the cowl where the carbon-fiber went off the edge of the mold. All carbon fiber parts are shipped with just a little extra loose carbon fiber fabric where it ran off the edge of the mold, and we always trim that extra material off so the part fits our airplane perfectly. Below, I put on some tape, nice and stright, to mark the edge that I will trim off to give me perfectly-sized cowling lower and upper halves.
And then, with a little spinning spiky wheel, run by air pressure, trim right through the carbon fiber to get a perfect straight edge!
And, after trimming, see how stright the edge is? Then I will just peel off the tape to have a perfectly straight cowling edge!
(OK, maybe not PERFECTLY straight, but a nice long sanding block will take care of that).
As well, when done, the cowling makes a very nice formal-wear evening-dress for Cone-Heads!
Then, of course, you have to make sure that the top and bottom are perfectly ROUND where they come together!
So, you simply drill little holes in top and bottom pieces, cleco them into place to hold them, and measure the left-right and top-bottom dimensions to make sure they are exactly the same at the front of the cowling! If they are not, then you need to trim or add a little so the top and bottom pieces fit together perfectly to be perfectly round at the front (to fit the spinner) and perfectly fit the aircraft body at the back (to fit the airplane!)
Ah yes! Round! This is nothing more than an upper and lower carbon-fiber cowl cleco'd together, while I sand around the interiror edges to make it perfectly round on the inner diameter as well. The whole cowling weighs only a few pounds. No more than cardboard. But stronger than metal.
Now this piece goes INSIDE the cowling to let air into the engine. I am pointing along the direction of airflow now. You will see that the entrance is sort of SMALL, but the interior air duct gets much WIDER as it flows aft. This is good because it will slow the air way down and raise it to a higher pressure... a very simple ram-air turbo-charging that will also lower drag inside the engine air inlet and oil cooler because the air will be going much SLOWER after the duct expands it. People SEE the outside of the airplane, but the inlet and cooling drag matter just as much! This inlet gets it RIGHT!
And this is how we get the edges really straight... a long sanding block! Really easy! This peice will fit INSIDE the cowl to decelerate the air smoothly, a lot, for ingestion into the engine and oil cooler.
And then finally the lip that goes on the leading edge of the cowl, heated to keep ice from forming on it. I sand the trailing edge here so it is nice and precise and fits in place perfectly.
And this is what it will look like on the nose of the plane, under the spinner:
When done, this cowl MAY have lower drag than the standard cowl... we will see! (by comparing the speed of my plane to other Evolutions at exactly the same torque and rpm) Wanna race?
Before you take my bet to race me, be sure you read the section on engine-installation coming up. You may guess that my engine is... not normal.
Oh yah... it fits!