Upper Cowl side hinge with engine installed ?

I elected to do my cowl after installing the engine and mounting the spinner back plate. I'm currently in the process of fitting the lower cowl.

Looking ahead to fitting the upper cowl, I can't quite figure out how one goes about drilling the upper half of the side hinges with the engine in place. Without the engine, it would be easy to reach through the nose of the cowl to hold the hinge in place while match drilling through the upper cowl & hinge.

For those of you that installed the cowl after installing the engine, how did you go about drilling the upper half of the side hinges?

won't be a problem

I found that the curvature of the lower cowl puts a bend (along the line of the pin) in the hinge halves. That bend does a pretty good job of preventing the upper hinge from folding inward. I was also able to get my fingers through the cooling / air inlet openings of the upper cowl to add a bit more stability to the hinge for the first drilling, then used sequential clecos from front to aft. Finally, I was very careful with my drilling technique and used minimum pressure to drill through the aluminum.

Just did this and it's easy. First, I pre-drilled the upper hinge half using my rivet fan spaced at 1" increments. Mount the upper hinge half on the lower hinge half. As another poster said, this holds the hinge up and is fairly stiff. Get your upper cowl mounted the way you want. I used a hole finder to find 2-3 holes along the hinge line and drill them. Then use your rivet fan, mounted to the holes just drilled to drill the rest. Since you used the rivet fan to pre-drill the hinge holes, it will match up accurately.