BriSCA Formula 1 Stock Cars is a class of single-seater stock-car-racing in the UK with custom-built cars, with races conducted on walled oval tracks of either shale or tarmac of approximately a quarter-mile in length. The cars are of an open wheel design. The cars may be of any horsepower and drivers can use any engine they choose, with Chevrolet based small or big block V8 engines being the most popular. The season runs from March through to November, with occasional meetings during Christmas time.