Rolls-Royce R engine was invaluable in the subsequent development of the Rolls-Royce Merlin engine and the Spitfire. A de-rated R engine, known as the Griffon, was tested in 1933, but it was not directly related to the production Rolls-Royce Griffon of 1939, of the same exact bore/stroke and resultant displacement figures as the "R" design. Three examples of the R engine are on public display in British museums as of 2014. Rolls-Royce realised that the Napier Lion engine used in the 1927 Supermarine S.5 Schneider Trophy winner had reached the peak of its development, and that for Britain's entrant in the next
Rolls-Royce/MAN Turbo RB193 Rolls-Royce/MAN Turbo RB193 The Rolls-Royce/MAN Turbo RB.193 is a vectored thrust turbofan engine designed and manufactured by Rolls-Royce and MAN Turbo in the mid-1960s. The engine test flew in its sole application, the VFW VAK 191B VTOL fighter aircraft but production did not follow after cancellation of the associated aircraft project. The RB.193 was a joint development project by Rolls-Royce/MAN Turbo originally designed to meet a requirement for the VFW VAK 191B project, design work commenced after a contract from the Federal German Ministry of Defence was signed in December 1965. Bristol Siddeley (from 1966 part of Rolls-Royce) were sub-contracted