Chapter 23 – Top cowl aft edge retrim

Today was yet another lighter build day.  I started working out again and between that and all this vehicle registration and some minor repair stuff, I was lagging on the power meter.

I grabbed a shot of the spinner and flow guide installed with the top cowl original aft edge in place…

It looks pretty darn snazzy compared to what I had before but there’s just not enough clearance between the top cowling aft edge and the spinner/flow guide.  Although I do like how much of the flow guide is covered here.

In addition, the original aft edge of the top cowling just isn’t straight.  Obviously there’s no “rule” that says it has to be, but since I’m trimming the top part for clearance I decided to trim the outboard edges to straighten up the top cowl aft opening line.

After spending a good bit of time measuring it all up and using the laser to ensure it was a straight line, I cut the aft edge of the top cowling… again!  As in Part deux.

I will note that the outboard edges are straight, while I did leave just a bit of aft slant in the part that curves up, over and around the spinner/flow guide.

I then mounted the spinner and flow guide into place.

Now, I was shooting for 3/8″ (0.375″) clearance, based on the plans stating to have at least 0.4″ clearance between the cowling and the flywheel.  I’ll admit that this configuration here only gives me just at 1/4″ clearance.  I will work the inside edge of the cowling around the spinner/flow guide which will essentially make it rather sharp, but should give me at least another 0.030″ of clearance.  I will also “thicken” the cowling at the final 1/2″ during finishing to allow me to sand a bit more of the underside away and give me at least another 0.030″ in clearance (about 1/16″ extra, 5/16″ total min.).  I’ll then assess from there.

Again, here’s Dave B’s spinner and cowling, which is what motivated me highly to add back a bit more of my original top cowl edge to make mine not look so funky.  I think his still looks better than mine, but I am a VERY close second!  haha

And with that, I called it a night folks!

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