SECTION 47: SPINNER & COWLING

Check for more recent updates here

Modifications to Consider

Hub and Blade Proxies
- For Hartzell see VAF thread 3/2024
- For Whirlwind (1.6" spacing), see 3D-printed parts.

Split Lower Cowling
- FB thread 8/2024 with a photo in the comments from Van's RV-10 with split lower cowling
- See also information about potential interference of particular skybolts with the exhaust system in this FB thread.
Cowl Paint
- Some builders paint their cowl white with two-component or single component epoxy paint to better see baffle air leaks or oil leaks. Consider these products:
  - Kirker Enduro Prime
  - Totalboat Bilge Paint
Cowl Heat Shield
- It is essential to shield the cowl from the heat radiated from the exhaust pipes. Several products are available. Builder usually seal the edges with high temp RTV. A more complete list will follow. For now, consider these products:
  - Heatshield Products 721202
  - Vans EA EXHST/COWL SHIELD
- Some put fiberfrax underneath the foil in extra hot areas right next to the exhaust pipes:
  - 1/8" Fiberfrax

Step 3: Don't assume your floor is level, better to take a tube level (any transparent hose filled with water and at least 3/8" in diameter). Can be used to level the plane spar end to spar end on the outside, and cowl corner to cowl corner.

Step 7: The kit comes with plain hinge pins however the plans show hinge pins with tabs welded on. Vans sells these special pins ($54 each):

Note: Long lead times as of Sept 2026. They are not cut to length, so 6' long, means expensive shipping

If you are using Aerosport's cowl hinge pin covers, check section Aerosport_Hints.

Some builders prefer a hidden hinge. The oil door opening however does not have a flange on the edge where the piano hinge usually goes. Cooling air can escape through that gap if you use a hidden hinge. One option is to craft an aluminum flange held by a base plate that goes underneath the hidden hinge on the cowl side. Such a base plate is about 1.6" x 4" to hold the flange and be flush with the outer edge of the hidden hinge.
Some builders prefer Hartwell latches. Those come in different variations under the same Spruce order number. They keep them all in the same box. You need to agree with Spruce that out of their stock, they pick two of the 64/1000" sub-type. There is a 64 imprinted on the underside of the moving part. You can also use other sub-types for thicker skins but then you have to shim the latches. The cutouts for the Hartwell latches is available on the CAD page.

Contents