Announced in 1929, the magnificent Phantom II served the role of Rolls Royce s flagship model for six years and set the standard for other manufacturers of luxury motorcars the world over. Central to the new car was a new six cylinder engine that shared only the bore and stroke dimensions with the outgoing Phantom I unit. Key developments included a crossflow cylinder head, separate inlet ports, improved exhaust manifolds and a bump in compression that released an additional 20 horsepower.