THE SPORT AFLOAT

TH SPORT AFLOAT

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M R. GAR WOOD resembles Capt. Sir Malcolm Campbell in that he is never too old to have another cut at a coveted record.

Thus, on Friday, March 20th, at Indian Creek, Miami, Gar Wood regained for America the world’s motor boat speed record with a mean speed over two runs of 102.156 m.p.h., and thus beat the record which the late Sir Henry Segrave set up in tragic circumstances, last June. The same boat, Miss America IX, was used in Gar Wood’s successful attempt as had been used when he established a world’s record previous to that of Segrave’s, but the engines (two Packards) have since then been supercharged.

Great ‘Britain’s defender, Mr. Kaye Don, is due to make his attempt in a day or two (at the time of writing), but it is reported that the Rio Parana is rather full of driftwood and although extensive clearing operations are in progress, is will make Don’s attempt more hazardous. We can, however, wish him the best of luck, while Kaye Don himself is confident that he can exceed the speed put up by Gar Wood, whose record he regards as lending more spice to his own attempts.

Straight from the” Sea-Horses” Mouth.

News has just come to hand that there are to be some material changes in Johnson outboard motors for the coming year. The particular engines of the Johnson range that have received attention are not indicated, but from the changes enumerated below, it would appear that the racing models are the ones M question, and if this is so we can confidently look forward to a general revival in the sport, when the largest individual manufacturers of outboards perparesomething new. Alterations are being made in the compression ratios

which are being raised, while both pistons and cylinder heads have been redesigned. Those motors that last year had carburettors working on the venturi principle are to have the more common float feed type of instrument for 1931. The most important modification of all, and one which definitely ranks the Johnson as something different, is the adoption of force feed lubrication by mechanical pump.

Points for Mechanical Oiling.

If, as I hope, the lubrication of the 1931 Sea Horses is solely by pump, then Johnson’s will have established a precedent as regards the two-strokes, which are, at present, supreme in the outboard world. Why the idea should have taken so long to catch on is a mystery, for it is not new, and in the only other sphere where the two-stroke is at all prominent, that of motor cycling, petroil lubrication is the exception rather than the rule nowadays. With an engine designed for petroil lubrication, it is obvious that where the oil goes, so may the petrol also, with detrimental results. Further, the lubricant has to find its way into a bearing from the outside and as it is much easier for the oil to travel up the transfer port, an excess is needed in the crankcase to ensure that an adequate supply goes the way intended. Again, it will be obvious that the thickest of blue smokes behind the motor is no guarantee that each bearing is securing a requisite amount of oil. The excess of oil, however, contaminates the charge, with consequent loss of power and renders it impossible for the plugs to last long, and thus the reliability factor is reduced. The ratio of oil to petrol is not constant and the fact that the high revving, large capacity motors use more gallons per b.h.p. does not alter the necessity of increasing the proportion of oil in the petrol. A point which has, no

THE SPORT AFLOAT—continued.

doubt, prevented many a prospective purchaser from buying, is the messiness of outboard motor boats : this mess is of oil left by the petrol evaporating from the overflow of petroil mixture when the carburettor is flooded, or from the blow-back through the air intake. With forced feed lubrication all these disadvantages are remedied. The lubricant reaches the bearings through drilled oilways and only the slight oozing of oil from these bearings reaches the crankcase, enabling a very pure charge to be induced each revolution, and

giving the plugs a much happier time than is their lot with petroil. Of course, the mess of petroil lubrication is absolutely eliminated because only clean petrol which soon evaporates drips from the flooded carburettor. How much the absence of that oily bilge washing about the bottom of the boat would be appreciated ! 1931 Johnson owners will not be seen carefully measuring out a quantity of oil, tediously pouring it into a petrol tin, and then shaking furiously, a proceeding which is too common to be humorous any longer.—F.M.