Early race cars are featured at the WeatherTech International Challenge at Road America

A 1916 Hudson on display at the WeatherTech International Challenge at Road America, Saturday, July 13, 2024, near Plymouth, Wis.

A 1916 Hudson is a blur of action around turn 3 at the WeatherTech International Challenge at Road America, Saturday, July 13, 2024, near Plymouth, Wis.

Jeff Miller (0) waits to enter the track in his 1977 Lola T496/Kohler car during the WeatherTech International Challenge at Road America, Saturday, July 13, 2024, near Plymouth, Wis.

The instrument cluster on a 1917 Hall-Scott on display at the WeatherTech International Challenge at Road America, Saturday, July 13, 2024, near Plymouth, Wis.

The overhead valve motor of the 1920 Lexington Minute Man Six Special on display at the WeatherTech International Challenge at Road America, Saturday, July 13, 2024, near Plymouth, Wis.

A 1920 Lexington Minute Man Six Special touts its wins at Pikes Peak while on display at the WeatherTech International Challenge at Road America, Saturday, July 13, 2024, near Plymouth, Wis.

A 1920 Duesenberg 8 race car exits turn 3 at the WeatherTech International Challenge at Road America, Saturday, July 13, 2024, near Plymouth, Wis.

A detail shot of the 1917 Hall-Scott at the WeatherTech International Challenge at Road America, Saturday, July 13, 2024, near Plymouth, Wis.

A 1917 Hall-Scott on display at the WeatherTech International Challenge at Road America, Saturday, July 13, 2024, near Plymouth, Wis.

Eric Ramos 1916 Romano-Sturtevant Special exits turn 3 at the WeatherTech International Challenge at Road America, Saturday, July 13, 2024, near Plymouth, Wis.

The 1916 Romano-Sturtevant Special exhaust pipes curve out of the engine bay as the car is on display at the WeatherTech International Challenge at Road America, Saturday, July 13, 2024, near Plymouth, Wis.

The 1916 Romano-Sturtevant Special on display at the WeatherTech International Challenge at Road America, Saturday, July 13, 2024, near Plymouth, Wis.

The Boyce Motometer radiator cap on the 1914 REO Speedster on display at the WeatherTech International Challenge at Road America, Saturday, July 13, 2024, near Plymouth, Wis.

A 1912 Packard “30” Racers on display at the WeatherTech International Challenge at Road America, Saturday, July 13, 2024, near Plymouth, Wis. The car was found in Argentina in the 1950s, in racing configuration. It is believed to be the oldest surviving Packard race car.

The 1912 Mercer 35J of Herbert A. Lederer (35) corners turn 3 at the WeatherTech International Challenge at Road America, Saturday, July 13, 2024, near Plymouth, Wis.

Brian Blain grips the steering wheel of his 1911 National around turn 3 during the WeatherTech International Challenge at Road America, Saturday, July 13, 2024, near Plymouth, Wis.

Dan Rhodes (34) leads a pack of cars around turn 14 during the WeatherTech International Challenge at Road America, Saturday, July 13, 2024, near Plymouth, Wis.

Chris MacAllister (5) talks to a crew member before going out on the track during the WeatherTech International Challenge at Road America, Saturday, July 13, 2024, near Plymouth, Wis.

Charles Test leads in his 1916 Hudson over Chris Helling in his 1912 Packard “30” Racer around turn 3 during the WeatherTech International Challenge at Road America, Saturday, July 13, 2024, near Plymouth, Wis.

Jeff Miller (0) enters the track in his 1977 Lola T496/Kohler car during the WeatherTech International Challenge at Road America, Saturday, July 13, 2024, near Plymouth, Wis.

A view of the tent where the Ragtime Racers were kept between their appearances on the track at the WeatherTech International Challenge at Road America, Saturday, July 13, 2024, near Plymouth, Wis.

A detail of historic motor items in the tent for the Ragtime Racers at the WeatherTech International Challenge at Road America, Saturday, July 13, 2024, near Plymouth, Wis.

A 1915 Stutz Bearcat on display at the WeatherTech International Challenge at Road America, Saturday, July 13, 2024, near Plymouth, Wis. A group of early race cars, called the Ragtime Racers had a display of the cars at the track for the weekend.

A view of a 1912 Packard “30” Racer 430 cubic inch “T” head 40-hp motor at the WeatherTech International Challenge at Road America, Saturday, July 13, 2024, near Plymouth, Wis.