The Napier Sabre was a British aircraft engine developed during World War II. It was a unique design, featuring a sleeve valve system that allowed for better airflow and efficiency compared to traditional poppet valves. The engine was primarily used in the Hawker Typhoon and Tempest fighter aircraft, providing them with significant power and performance. With a power output of up to 2,500 horsepower, the Sabre was one of the most powerful engines of its time. Its innovative design contributed to the success of the aircraft it powered, making it a key component in the Royal Air Force's efforts during the war.