Another day working only on the air filter box, and some suprises on the way.
First I begin by doing what I should have done yesterday, i.e make a template for the upper plate.
Here it is on the right with the original plate on the left. It show that the holes for the bolts are shiffted to the right.



Once all installed on the plane, there is a problem. As the bolts are no more at the center of the box, they are no more at the center of the filter. The top of the filter interfers with the two left bolts. Some builders have to modify their filter due to an interference with the carburetor, this technique is described so I will apply it : cut the top of the filter and the creat a new seal with some proseal.



Before cutting the filter, I verify that all the parts fit and that the gap with the moving parts are wide enough.
This is the mixture control arm with the hardware nedded to attach the cable. All looks good but I will have to check again the gap between the bolt and the cowl once everything is in the final position.



Then I make the cuts at the front of the box. The box is too long and would hinder the lower cowl removal. The picture shows the plate allready cut, but the cut on the fiberglass part is still to be done.



Then it's time to cut the top of the air filter. The picture shows the two cuts, and the good surprise is that the seal is still a seal, I didnit to cut completely through it so I won't have to redo the seal.



Then I install the alternate air door. This door can only be opened in flight to ensure air supply to the engine should the main air supply be blocked (by snow, ice or any other object). The opening will draw unfiltered air from the engine compartment.
Once open, it is supposed to be left that way and only closed on the ground



And to finish, I riveted the lower plate to the air box. The rivets used are small round head rivets used for the first time since the beginning of the building.
I now have to cut the upper plate according to the template and extend the scoop on the lower cowl toward the front of the air box.