Cowl Fitting and Sybolt Kit Question

[JVolkober]

Two separate questions here:

What is the best way to align the cowl for triming at the firewall? With the engine at an angle, it seems to me that I should align with the spinner plate with the result that the firewall end will be cut at a slight angle. Is this the way to go? The alternative, as I have read in other posts, is that the spinner and cowl will be out of alignment.

Second, I received my Skybolt delivery with only the aluminum strips. I want to start fitting those this weekend. Is there a preferred pattern to mounting the strips to the firewall; e.g. mount one from center top of firewall around to the side and use part of another to complete the side, or mount one across the top of the firewall and the continue with strips to complete the top and sides? Note I not using hinges to attach the top and bottom sections.

[BigglesRV7A]

The cowl needs to align to the spinner you have or are using. Yes the engine is offset and not only would it look shocking to not have the cowl aligned with the spinner, it would change the flying characteristics of your plane in a negative way.

The skybolt system I used didn't come with the metal strips and I had to fabricate my own. I used two strips running from right of centre at the top rear of the top cowl around and then down the sides. As long as the join line is not where you want to place a C/loc fastener, it will all work out fine.

Just my .02c worth.

Greg RV-7A FADEC

[RV8R999]

I recommend you find some short bolts that fit your flywheel and ensure you mount the backplate with all holes tightened (not torqued, just a bit tight) to ensure the backplate is flat when you are fitting the cowl.

I cut a 3/16" round spacer from some Home Depot luan and taped it to the backplate. Then I used my table saw to cut a piece of wood exactly 3" wide. I screwed a piece of .032 alum scrap to one edge and let it overhang the bottom of the block of wood about 1/16". I used this to trace a reference line 3" aft of the forward edge of the firewall skin by using the overhanging alum as a guide while sliding the wood along the firewall and marking with a sharp pencil. Then with the top cowl aligned with the backplate and taped into position I placed the block of wood back on the line with the alum strip along the pencil line and marked a line on the cowl using the wood edge as a reference. This provided me with a .032 gap along the perimeter of the entire cowling (although I ended up with more after some sanding and other issues). It worked well for me. Others may have a better technique.


Of note with the skybolt system. I'm using Skybolt for the entire cowl (no hinges). One thing I've noticed is due to the nature of the floating fasteners (the ones along the firewall) it appears the cowl is never EXACTLY aligned the same way twice. The variance is very small but will be noticeable if you are attempting a very small gap all around. At least this has been my experience.

This is my opinion only, but I think drilling the adjustment holes were a waste of time. The locking band can be easily reached from the backside of the fastener barrel with a scribe. I drilled them for the top cowling then stopped doing that for the rest. Not a big deal either way, just thought I'd share

Ken