Hi all!

I finally worked up the courage to fire up the dremel and start carving up my cowling.

I've attached a picture showing the bottom of the cowl with the cutout that I've made for the engine.

It is my plan to extend the opening that I have now all the way back to the rear edge of the cowl as I will have to slip it over the stock exaust to install it once the exhaust is in place.

Is this how you would do it?

David:

Unless you plan to be taking the cowl off often, I'd clean it up as it is, and secure it. And just realize I had to pull the muffler to get the cowling off.

Couple of reasons for this, not the least being strength. It's stronger the way you have it.

Just trim it to have about 1/8" or so clearance all around, and enjoy.

Bill

I think I'm going to have to make a cut-out for a couple of reasons. With the cowl in one piece, I cannot get the cowl on th efuse far enough back to provide a even gap between the back of the spinner plate and the front of the cowl. It's close, but no cigar...I've already feeled the covering off the bottom of the fuse and removed a bit of balsa. I don't want to remove any more. Opening up the back of the cowl will give me a little "give", enough I hope to allow me to get the cowl aligned perfectly.

Also, I was hoping to terminate my fuel fill line by securing it to the bottom of the firewall and leaving a little stub with a plug hanging out there.

Some folks have also said that I would need to clamp my fuel line while filling to prevent flooding the engine. This opening would give me a spot to do that too.

Finally, with the engine I am running (OS 46FX) I have no idea of how I would attach the exaust if the cowl was secured first. I would have to make holes in the side of the cowl opposite the exaust to put the screws through, I think that would be ugly.

Just got back from a long business trip and saw your post this morning. I don't know how far you have gotten during the past few days, but here is my nickel-

I recently completed the cowling on my Nobler, which looks similar to the one you are working on, and I also fitted an inverted 46FX. This was my first cowling and I am quite pleased with it.

I had the same problem with the tight fit but kept at it and eventually managed to get the cowling to slide around the firewall leaving an adequate gap in front for the spinner. And I do think that leaving a cowling material all the way around the firewall adds strength, but I made the hole quite big to make sure I had adequate cooling. I drilled two small holes just large enough to get an allen wrench through to enable removal of the muffler. I don't think they detract from the way it looks. I also drilled a small hole to enable adjustment of the low speed screw on the carb.

I used a 3-tube tank setup with a filler valve functioning as a fuel dot. The inverted engine does tend to flood if I am not careful, but I found that if I stop filling the tank as soon as the level reaches the overflow (tubing to the muffler), that there are no problems- no clamp is needed. I first try to start the motor by hand before putting the electric starter to it, just to make sure. Once started it runs great- it actually runs smoother than my other two 46FX's for some reason.

I have at least two dozen flights on the plane and haven't had a need to remove the cowling since the initial setup. There are some pics in my gallery if you want to take a look.