What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Cowling fit questions

AeroDog

Well Known Member
Friend
After sanding to the scribe marks and fitting the cowling to the airplane (engine and prop are installed) I find the front face of the cowling touching the spinner. Obviously the cowling has to move aft. Using the search function it appears that I need approximately 1/4 inch clearance. At the aft edge of the top cowling the cowling already overlaps the front top skin 1/2 inch or so. I'm guessing (can't tell from the KAI) that the top cowling should butt up against the front top skin, not overlap it at all. Any advice on all this stuff will be appreciated. Also, I'm curious how much builders are needing to trim the aft edge of the top cowling beyond the scribe line. Thanks.

Jerre
 
Cowl

It sounds like your engine is installed. The easiest method is a reference line. This is how I did my 7A.
Measure and draw a line exactly 2" from the firewall all the way around. Start with the top cowl.
Set it in place with the spinner distance you want. You also need to somehow center and level the nose bowl. The aft edge may overlap.
Measure 2" from the reference line and mark the cowl. That cut should get you pretty close to a flush fit against the firewall.
Repeat on the bottom cowl. That's the short version.
 
I did mine the same way Larry did with reference lines to get an accurate cut line. You’ll want to make your cut slightly long of the cut line and kind of ‘sneak’ up on it with a sander. Making some sort of jig to hold the front end in the right place is necessary. I use a jig that a couple friends and I bought from Fly Boys at Oshkosh:



The jig is adjusted to lay flat against the cowl where your spinner backplate will be. I set mine up for a 3/16” gap, and it worked out well.

52FA0447-2F1E-4B01-87BB-A8B2BEA39C32.jpg
 
Fitting the cowling on the older ULS RV-12

Since you have the engine installed, I would recommend following the instructions for the iS version.

The iS cowling instructions are in section 37iS/U and can be found on the Van’s website.

The iS instructions locates the front of cowling to the back of spinner.

If I had followed the iS instructions I would have had the same issue that you are having.

Brett H
Columbus, IN
 
Back
Top