I was very interested to read, in the November Motor Sport, how the Sunbeam company obtained detailed information on the 1913 3-litre Peugeot racing cars. You state that the engine was bench-tested at the Sunbeam works, but does anyone have first-hand knowledge of this appraisal?
Other sources have quoted 90 b.h.p. at 2,900 rev./min. for the 3-litre Peugeot engine, which agrees on a b.h.p./litre basis with the “just under 100 B.H.P.” which your informant Mr. Mitchell remembered in connection with the 3.3-litre Sunbeam derivatives.
With regard to the engine of the 1914 TT Humber, this differed from the Henry concept in at least one important detail. The included angle between intake and exhaust valves was 90 degrees whereas the 1913 and subsequent Henry designs all used a 60 degree valve angle. I am indebted to Kenneth Neve for confirming this fact and I enclose prints of the cylinder block and piston drawings which I copied from Mr. Neve’s own drawings earlier this year. You will note that the piston crown has a pronounced dome, whereas on a 6o degree valve angle design the use of more nearly flat-topped pistons would be expected.
Still on the subject of the 4-valve per cylinder concept, I wonder how many of your younger readers are aware that the twin-overhead camshaft 4-valve per cylinder layout preceded the “hemi”.
Can anyone enlighten me on the Frontenac conversion for the Model-T Ford? It is well known that the Frontenac (or Monroe) engine which powered the 1920 Indianapolis winning car was of strictly Peugeot layout. Was the same manufacturer’s conversion a central spark plug 4-valve design and did it have o.h.c. or pushrod operation?
Rye. BRIAN PRITCHARD LOVELL