Nappier versus Rolls-Royce

Napier versus Rolls-Royce

Sir; I read with interest Mr. J. P. LaT. SheaSimmonds’ letter in the De.cember issue and Air Commodore F. R. Banks’ comments in

February regarding the above and in particular the figures relative to the Merlin and Griffon engines.

For many years I was associated with the Derby concern and still have extracts from a paper read by Mr. A. C. Lovesey in the late ‘forties covering this subject. Mr. Lovesey stated that in 1937/8 a Merlin III with strengthened pistons, gudgeon pins and connecting rods achieved 2,160 b.h.p. at 27 p.s.i. boost on special fuel, (Did Air Commcidore Banks develop the fuel?). This engine was produced to attempt the world’s air speed record in a cleaned-up Spitfire but as I recall the attempt was called off as the Germans put it out of reach. In 1944 a 2-speed, 2-stage Merlin of tb 66-70 Series was able to operate in

at 25 p.s.i. boost giving 2,050 b.h.p. ,,n 150 grade fuel and short endurance tests u, water injection at 36 p.s.i. boost gave 2.o Is. b.h.p. (BMEP 404 p.s.i. and IMEP p.s.i.). The Griffon 57 stihl in service Shackleton gives a take-off figure witl

injection at 25 p.s.i. boost of 2,500 !-•.

Johannesburg J. B. WATER’ :01.M’.