Pierce-Arrow Model 66 – 13.5-litre straight-six
Despite its reputation, the Royale cannot lay claim to the largest engine fitted to a production passenger car. That honour goes to a now largely forgotten American automotive pioneer, Pierce-Arrow with their Model 66 and its 13.5-litre straight-six engine meaning each cylinder displaced two and a quarter litres.
Originally a bird cage manufacturer – which led to a nickname of ‘Fierce Sparrow’ – the Pierce-Arrow was an early innovator, the first to introduce power brakes and steering, hydraulic tappets and light alloy construction. Launched in 1910, the Model 66 was held as the pinnacle of US automotive engineering against its rivals such as Packard and Peerless (together the firms were known as the ‘3Ps’ of American automotive luxury). Originally displacing a mere 11.7-litres the straight-six produced 66 horsepower, hence the name. Enlarged to 13.5-litres added an additional 100PS, the name remained unchanged but the car was now capable of 80mph, despite being clad in one-eighth inch thick cast aluminium panels. Of the 1,250 examples hand built between 1910 and 1918, only 14 are known to survive.
Main image by Jayson Fong, Cadillac and Pierce-Arrow image courtesy of Bonhams, TVR image courtesy of Motorsport Images.