ON A COLD AND FROSTY MORNING.
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Seasonal Suggestions from our Driver and Mechanical Readers.
THE RECENT cold snap—which may . still be continuing when these lines appear in print—has given the demon of difficult starting the chance for which lie has long been waiting, and many a driver of a 40 h.p.• four-or-fivetomer has had cause to rack his brains for some expedient by which the hard labour of persuading his sulky engine to get a move on may be lightened, and much time saved. The following hints on easy starting, therefore, besides being seasonable' are also likely to be welcome to many adriver.
The first letter we reproduce almost verbatim. It is written by " J.W.„ of Westminster, and, although it is only likely to be of direct service to those readers whose lorries are equipped with Zenith carburetters, we have decided to award this contributor the Ifis. prize this week.
Most readers," he says, " are familiar with the habits of the Zenith carburetter on cold mornings. Having had casion to make a thorough investigation of the " innards " of this carburetter, when I discovered that the "starting" part of its works really consists of a miniature carburetter which has two air ports which are quite distinct from the main air intake, I decided to experiment on my own, and see if I could not make some use of this information.
"I tried first the effect of a slip of wet paper, which, when starting, I temporarily pasted over these two small
holes. The effect was miraculous. I
decided to try to make an engineering job of this device. In this I was successful, as the following description and the accompanying sketch will, I think, demonstrate.
" Above these two ports is a small screw, thepurpose of which is to facilitate adjustment of the slow running jet. I cut a spade-shaped piece of brass (see sketch), slotted it in the handle portion so that it would slide up and down on the screw, and shaped it so that, when in the top position it covered the two 'holes, and when lowered as far as it would go it uncovered them. I drilled a small hole in the top for the attachment of a Bowden wire, the other end Of which was located in the driver's cab.
"When starting, the slide is drawn up to cover the ports, enabling an easy start to be made.
"A small spring, washer from a sparking plug electrode, fitted under the screw, serves to hold the slide against the body of the carburetter, firmly enough to ensure the exclusion of air from the ports when it is in use for its proper purpose, but not so tightly as to prevent its dropping down again when the cord is released."
" G.F.A.R." begins a rather breezy, letter in this way : "I have just been reading what a lot of trouble " G.T.," of Glo'ster, is to himself on a frosty morning, when he has to start his vehicle.
"It used to be the same In our garage, too, but nowadays those quirks and gadgets are relegated to the scrap heap, in favour of the following method, which has been applied to all the machines under my charge. " A 1-in copper pipe is led from a union on the top of the inlet pipe to a suitable pet cock, mounted on the dash so that it is accessible from the driver's cab. The best type of cock is one which is fitted with a funnel top, as shown in the accompanying sketch. .
"Now, whenever a driver is putting his vehicle up for a winter's night,. he fills this funnel, before switching off, with paraffin. The cock is then opened, and the paraffin sucked into the engine, being distributed throughout the four cylinders in fairly equal proportions. He then immediately switches off. The result is that next morning the handle can be swung without any trouble whatever."
" W.C.S.'s" idea is good, but his method of putting it into practice is crude. It is only of value, too, in connection with those engines which have no covers over the valve gear. He cuts four rectangular washers, so thick, that when inserted between the valve tappets and the exhaust. valves they will just prevent the valves from closing. A. small hole drilled in each washer serves asmeans of attachment for a piece of string. When ready to start he slips the washes under the valves, when they act as a half-COMpression device. He turns the handle, starts engine, and then, by pulling on the string, removes the washers.