OIL AND R.P.M.

NE of the secrets of winning speed events such as the Ulster T.T . rests in the increased engine speeds —in other words in the raising of the number of revolutions made per minute by the crankshaft. The successful M.G’s were “revved up” to over 6,000 r.p.m. It seems incredible that the busy little pistons could, perform such an amazing feat when it is realised that each one actually travelled up and down the cylinder bores twelve thousand times in each brief minute— transmitting the force of three thousand explosions to the road wheels and dispersing the terrific heat engendered in the process. How these pistons stood up to such a colossal task without melting or completely distintegrating for over five hours of cruel, gruelling, racing T.T. conditions passes the imagination. Even

more inconceivable is the fact that they emerged unscathed and in perfect condition at the finish.

The somewhat dull, prosaic phrase “increased r.p.m.” is a typical item in the description of modern tendencies in sports car specifications and only a few years ago 2,000 r.p.m. was considered the limit that any engine, racing or otherwise, could stand.

To-day, however, improvements in methods from which pistons and other high speed parts are made—an accurate knowledge of the forces which have to be balanced, how to balance these forces and lastly, but most important of all, the evolution by scientific process of lubricating oils which can stand up to the terrific stresses imposed, have permitted these unbelievable r.p.m. to be attained.

In this connection it is interesting to note that the Shell Company in anticipation of the increased popularity of the sports type of car and, motor cycle have produced the new type of lubricant (already extensively used) which they call Aeroshell. This new oil is really a scientific achievement ; it is produced by several entirely new processes, one of which is electrical stabilisation, which gives a far greater degree of lubricating efficiency than can be found in ordinary lubricants.

Aeroshell will be essentially an oil for the few ; it costs a little more than standard grades of oil because of the expensive processes involved in its manufacture, but for the discriminating type of car or motor cycle owner who places efficiency above everything else, Aeroshell can be recommended for serious consideration.

S. A.