Badland Part 103 Pilots and Builders Forum

No progress on Polini startup. Saturday was grandson's HS graduation day. However, this morning a friend showed up and lent a set of badly needed hands to the cowling fitting effort. He pretty much held the beast in position while I used my only 3 long neck cleco spring clamps to fine tune the location of the cowling. We then drilled the mounting holes thru the fiberglass (with 0.016" tabs fiber-glassed-in) So now I have the cowl attached to the frame usinbg 6 of the 8 mounting tabs. I used the aluminum 10-32 nutserts and stainless 10-32 wood-bearing washers and machine screws.

The cowl bulges slightly at the transition from the vertical too the horizontal sections where Chris has provided an additional welded tab. I'll add a spacer between the tab and the cowl skin to complete the mount at those two locations. I do have a slight bit of trimming to do on the starboard-side exhaust cut-out ... only about a quarter of an inch.

Front view:



Port-side ... slight trimming at upper left is required.


Starboard side:


Port-side "ear" mount:


Port-side vertical mount (typical):


Also, here's the location of the USB GPS antenna. It is attached to the USB charger and I'll only need to see the small blue light to note that it has a strong signal lock.

This is turning out great.

Looking at the cowl, I think I might be able to remove the bumps without too much difficulty, smoothing out the cowl. Along with that, Since my carbs on the F-23 will stick out like the carb on your Polini, I'm thinking it would be easy enough to create intake scoops off the cowl to direct air into them.
I think with the scoops, the air pressure is above atmospheric all around the intake to the carb. When flying without a scoop, the air passing the intake will cause a negative lower air pressure than atmospheric. Not saying this is an issue. I'm just looking for maximum efficiency. The question comes in, is the extra weight of the scoop(s) worth the increase in performance of the engine?

As always Kurt, it's looking really good.

Todd

Kurt, you are doing fantastic work. It looks great. I suspect that Todd is correct; that the humps might be easy to remove if one desired a "cleaner" look.

At any rate, it looks like you got a handle on doing fiberglass work pretty quickly!

As an old P&WA guy (still like those round engines), I like the bumps-look. With my interminable fiberglass efforts, I don't think the work required to remove these small bumps is worth the effort.

Aa predicted, thw rains have come so no progress on engine start.

Now if only someone built a little round engine that fit under that cowl! Now THAT I would be interested in, as I am also a fan of those round engines. There is nothing sweeter to me than the sound of one starting cold.

Rain again? We finally got some sun over here...sort of. June gloom has arrived!