The cowling is still a work in progress, I purchased the universal horizontal split cowl from Sonex. Mine was about 1/8" short on the bottom and 3/4" short on the upper. Plus mine fouled on top of the oil cooler...grrrr! The bottom one went on pretty easy, the tricky part is getting started and holding the hinge halves in position until you can get a couple of clecoes holding them on. I have enlarged the hot air outlet. If you only cut out what is specified, a lot of the hole is obstructed by the engine mount and the exhaust pipes. So I have made darn sure that I've got at least the minimum required area clear of obstructions. I used the off cuts of fibre glass to make the outlet fence and extend the bottom half of the cowling. It was a quick and easy way of making it longer. Everything needs to a bit of filling and sanding to finish off. I didn't want to finish this until the engine cooling baffles are done in case of stuffing things up.
I didn't have any release agent and I was looking around my shed looking for inspiration as to what to use as a mold to make the cowl longer. I used a scrap bit of 6061, I even left the plastic on as I figured that it would help and a worse case scenario would mean peeling the plastic off of the metal to pull it apart. It turned out to be the best idea I've had for a while. As I pulled the clecoes out, it just simply fell away from the new fibre glass, no sticking or anything plus it was pretty smooth as well. I had to do a happy dance after that one.
This is the cowl roughly trimmed to shape and sitting in position. As you can see there remains just a few hours of filling and sanding still do.........nobody should say 'just a few' when it comes to fibre glassing!
The last picture shows the two cowlings sitting on the aircraft. I haven't installed the mounting screws as of yet. You can see the hump that needs to be made to clear the top of the oil cooler. I have just rested the prop hub in position to check that it all fits. At this point I'm feeling pretty proud of myself.