From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Discussion with Packard on engine design ideas, including injection engines and bore/stroke ratios.
| Identifier | ExFiles\Box 178\2\ img050 | |
| Date | 26th March 1940 | |
| Serial No. 53 OY 13/D/Mar.26.40 Handwritten: Ev{Ivan Evernden - coachwork} Please circulate to design office & keep in your files Rolls-Royce, Ltd. Derby, England March 26, 1940 Hives Packard Ideas (March 25, 1940) Injection engines Stroke-bore ratio Con. rods Automatic gearbox Had a talk with Walter Griswold of Packard yesterday covering various matters amongst which:- Starting Injection Engines Is not familiar with the problem as applied to safety fuel and injection on intake or in manifold. On Packard diesel, however, glow plugs were used for starting. These took 150 watts each, but only for a few seconds. Were extremely satisfactory on the diesel, using diesel fuel. Engine Development Packard engine has 6" bore (actl. 6⅛" stroke, I believe). W.R.G. thinks engines can be increased in power better by increasing bores than by multiplying cylinders. On car work is urging square engines, and on high power engines for boats, etc., is urging stroke/bore ratios of .9. (A similar movement is going on in development of light plane engines.) Believes we have been unduly scared of large bores and that with careful study of heat flow in pistons, adequate oil cooling of underside of head and (possibly) reversion to semi-zephyr type, bores can be increased beyond 6¼", as high perhaps as 7", without trouble. Radial engines are already leading the way to higher bores. The enormous percentage of big end loading which is due to inertia, is all in favor of relatively shorter strokes. Also the consideration of frontal area. When multiplication of cylinders leads to master rod and articulated rod construction, with its certainty of big inertia loadings and rough engines, he feels there is the strongest possible urge to | ||