I don't care about the plane itself but engine it has is wonderful piece of machinery.
Cylinder had a sleeve inside it which was both rotating and moving up/down and thus opening exhaust/inhaust ports in cylinder.
Engine could stand more rpm than ordinary engine with valves but it needed good oil, lots of "TLC" (tender, loving care") and it had to be warm before start.
In France Tempests/Typhoons, powered by Napier Sabre with similar sleeve valves, had problems after cold nights 'cause sleeves were stuck because lubricate oil was too stiff when it was cold.
Solution: Mechanics did start engines once or twice in night...