1931 Franklin Series 15 Deluxe Custom Roadster

'Highest horsepower per cubic inch! - It's a claim many would like to have made and Franklin could say it in 1930, and again in 1931 for a non-supercharged, American engine. This was the second year for Franklin's 'airplane-type' engine with 'side-draft' cooling and improvements due, primarily, to higher output through a camshaft change and a redesigned cooling fan which now consumed only 4.5 horsepower.