I'd bought a cowl from Brian Alley back in September 2009 (The cowl arrives) and it has been stored in its shipping crate since then. Today I decided to make a start cutting it to fit. The first job was to get the join at the front to fit and cut out for the prop extension. Lots of sanding and use of a rotary burr on the inside angles got this to a good fit. The inside of the air intakes and the front of the sides were then match drilled together to fix the position of the joint between the cowl halves. Then the spinner backplate was installed on the prop drive extension to set the length for the cowl and first the lower cowl and then the upper cowl cut roughly to length. Temporary aluminium strips were clecoed to the firewall top, sides and bottom. Then the lower cowl was positioned and drilled and clecoed to the side and bottom aluminium strips. The upper cowl was then positioned and the correct overlap between the back of the upper and lower cowl established and the two halves match drilled and clecoed together. Then it was a case of marking minor changes to the rear of the two halves to centre vertically and horizontally the spinner backplate in the cowl opening and to ensure that there was an even gap of about 3/16" 
between the front of the cowl and the rear of the backplate, removing the cowl, making the adjustment, rechecking and repeating and repeating and repeating.....Eventually a good fit had been established and it was time to take some pictures despite dusk falling. The next jobs are to properly cut and make the side joins, to fit the airscoop which will feed air to the carburettor, and to match drill and rivet permanent mounting strips to the firewall which will carry the cowl mountings.
I hope the pictures show what a super product Brian has produced. His cowl carries the lines of the fuselage perfectly and then blends them into the spinner surround. It also fits perfectly width-wise at both the top and bottom. Of course the overlap of the sides can be adjusted to make them fit perfectly as well. Using my O-235-C2C engine and a 4" propellor extension I had to cut off about 1-1/2" from the back of the cowl.
