Below is the exchange I had via Email with Van's builder support. I'm not sure why they didn't give a more succinct answer than "it might work".
I have of course sanded the lower edge of the top cowl horizontal as-molded fiberglas, to the point where it matches the average thickness of the cowl (I didn't mean to imply use it having never touched it). But that sanding didn't move it by any appreciable amount.
So OK, I'm intending to use the upper cowl as-molded horizontal as the split line. Note that I now reailize I have an older green cowl, not a pink cowl, however that might matter, I don't know the differences.
In basic the sequence I've used so far and will use from here, after reading about many examples of fitting up RV cowls is:
-Worked to get the front round opening to nest/mate between the upper and lower cowls
-Installed the spinner ring on the engine, set the upper cowl in place, located and held the front of the cowl 1/4" to the rear of the spinner, did the 2" measuring thing and trimmed the upper cowl to the firewall.
-From here I'll fit the lower cowl up to the upper cowl, do the 2" measuring thing and trim the bottom, refit it again and do the 2" measuring thing on the sides and trim them.
-Then install all of the Skybolt fasteners around the firewall and fit the upper and lower cowls to them.
-Then do the final work to cut the horizontal splitline, and install the Skybolt fasteners along it. The horizontal split will be the last big cut.
-Then any other fiberglas work needed to make everything look good
AC.
My Question to Van's support was:
"Gentlemen,
It appears to me, that the as-molded horizontal split line of the green upper fiberglas cowl, is meant to be the final split line between the two halves.
There is a well defined added trimline on the lower cowl that can be marked and cut to match the top cowl, once the two halves are located and fitted at the firewall.
There isn't any direct reference to using the as-molded horizontal edge of the upper cowl as the split line, in the Van's instructions. It's straight as received and looks like the intended split.
Is this what Van's intends?
The pictures show the initial fitting, the upper cowl half horizontal split has not been trimmed from the as-received molding, and the lower cowl is tucked under it at this point. I don't see why I don't use the upper cowl horizontal as the split line, and trim the lower to it. This is an older kit, that I bought from a previous builder, I believe the cowl to be from 2005.
Tnx,"
Van's Response:
"Hi Andy,
It might work as a horizontal split line. But normally, you will end up sanding the upper and lower cowling to get a good fit along a line of your choosing. Unfortunately, there really aren't any shortcuts here.
If you think the existing edge will work for you (and it is flat and straight!), you could certainly go for it.
Best Regards,
Builder Support
Van's Aircraft, Inc."
