Now that I had set the top cowling's height in relation to the prop spinner, I needed to devise a way to block that cowl half so that it stayed at the perfect height. After measuring the gap between the small stainless steel fuel lines running from the engine's top-mounted fuel injection spider, I used 3/4" wood boards that sat on top of the engine lifter lines but under the fuel lines. I screwed a block of 2"-by-4" wood onto the forward ends of the boards and butted the boards back against the engine case aft end.
I was using a sheet of 1/4" thick oak vaneer (from the Home Depot Aviation Supply Warehouse) acting as a spacer between the prop spinner backplate and cowling forward edge. I had already marked reference lines on the prop spinner backplate to show where the forward center cowl flange edges should align when the cowling is at the proper height. The "proper height" included allowance for future engine sag. I then started the process of: - removing the cowling - sand down the two blocks a little at a time - reinstall the blocks atop the engine - reinstall the cowling and check the alignment and height - repeat... - repeat again... - ...until the cowling sat at the proper height with the forward flange edges aligned with the prop spinner backplate.
I checked again, this time with the 1/4" oak veneer spacer removed from behind the prop spinner backplate. PERFECT alignment, height, and spacing.
