After consulting Kerry at Sonex about my engine mount installation I concluded that the position I had it in was satisfactory. Vertical position is perfect and horizontal position is just under 1/8” forward but that is less than a lot of other builders have it, the cowl comes oversize so that won’t be an issue. So I have now drilled the mount in place, starting at 1/8”, updrilling to 3/16” and finally to 1/4”, I also countersunk the holes for the machine screws. However, I did not fully countersink the holes, it seems too much material is taken away from the attach angles if I do that. It should not be a problem, I’ve seen other builders do the same. Finally I primed the mount where the powder coating got removed and the attach angles with the green zinc oxide primer, I’ll use Duralac on the machine screws as well.
