Sam Swift of Nashville, Tennessee has some nifty cooling ideas on his Pitts S1-D race plane.
One of the more obvious are interchangeable engine air inlets. Designed in SOLIDWORKS by Brian Kelly (the radial engine RV guy) the inlets allow Sam to trade drag for cooling air as the racing situation allows.
The change evolution couldn’t be easer. The inlets simply slide into the cowling and are held by tape (racers love tape). When the weather is cold—defined by Sam as 50°F or cooler when it comes to Reno racing—he can run the smallest aperture inlets. They measure 2.5-inches of inlet opening and do the most to reduce cooling drag.
As the weather warms Sam finds the medium sized 3.5-inch inlets necessary, and that’s what he’s running right now at Reno. He’s also spritzing spray bar water on the cylinder heads, so keep that in mind as well.
The big openings measure 5-inches and are what Sam runs generally when not racing, flying cross country and generally chasing himself around the sky.
If you’re interested in these inlets for your application Sam suggests speaking with Brian Kelly directly at email@example.com.