For DRIVERS, MECHANICS & FOREMEN.
Page 21
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A PRIZE OF TEN &BILLING'S is awarded each week to the sender of the beat letter which we publish on this page; all others are paid for at the rate of a penny a tine, with an allowance for photographs. All notes are edited before being published. Mention your employer's name. in confidence, as evidence of good faith. Address„ D., M. and F., "The Commercial Motor," 7-15, Bosebery Avenue, London, KC. 1.
Lamps Alight.
On' Saturday, March 29th, light your lamps at 6.55 in London, 7.38 in Edinburgh, 7.1 in Newcastle, 7.7 in Liverpool, 7.2 in Birmingham, 7.5 in 'Bristol, and 7.51. in lhlbliii. From midnight on March 29th the Summer Time Act comes into force so that the foregoing times should be advanced by one hour.
Useful Tools When Dismantling Pistons and Gudgeon Pins.
The sender of the following communication has been awarded the las. prize this week.
[l956] " H. J.0." (Chiswick) writes : —" The accompanying series of sketches show four handy tools for use when dissembling pistons, gudgeon pins, and connecting rod bushes. They are (1) a split pin remover, (2) a special spanner for removing the screws which are fitted to prevent gudgeon pins from turning, (3) a gudgeon pin extractor, (4) a connecting rod
small-end bush extractor. They are simple in construction, and I think no supplementary written description of them is necessary, the sketches being sufficient in themselves to enable any mechanic to make the tools.
"The following are rough particulars as to the size and strength of material which might reasonably be employed in connection with, say, a 3-1 in. piston. The split-pin extractor (No. 1) can conveniently be made from in. square steel. It would be about 67, ins, over all. The points should be hardened. The special setscrew spanner (No. 2) had better be made from--111in. or -4 in. round bright steel. The spanner end of this, too, needs to be hardened. For No. 3 the gudgeon pin extractor, the band which passes round the piston should be about 1i in. wide and /tin. thick. The hole in the centre, of course, needs to be sufficiently large -to allow of the gudgeon pin passing through. The crossbar, which carries the
forcing screw should be the same width as the band, and about in. or I in. thick, tapped at the end for
in. screws. The forcing screw itself is in. Whit., sufficiently long to enable it to go right through the piston, whilst a little of it still projects on the outside of the crossbar. No. 4 for removing the bush from the small end of a conne-cting rod, could be made from either a forging or a malleable iron mating, whichever can be most conveniently obtained, it should be made plenty strong enough. The mechanic who makes this will be well advised not to cut the weight down. Very frequently these connecting. rod hushes are put in very tightly, and cause a lot of trouble, when they have to be removed. A in. screw ia needed for this as for tool No. 3. The. points of these screws, of course, must be case-hardened. "A few words may be necessary with regard to the two small fittings marked A, and which might be called adapters. These adapters are necessary in the case \of hollow gudgeon. pins, and they are also essential for tool No. 4. In the former ease the small diameter of the adapter must be an easy fit in the bole in the gudgeon pin. The outside diameter
should be in. leas than the gudgeon pin diameter. Similarly -with that for the connecting rod bushes ; the small portiex should be an easy fit in the bush itself ; the outer diameter should be slightly less than the hole in the connecting rod itself. These adapters, of course, should be case-hardened all over, and when in use a spot of oil on the end of the screw or in the cup of the adapter greatly facilitates the working of the tool."
A Winter's Tale.
[1957] " W.G.11." (London) writes :—"Taking & hint from your editorial suggestion which appeared on the
' and _F.' page of your issue of February 27th, I have pleasure in submitting the following story of what happened to me on a recent journey from Bedford to London with a Burford 2-ton lorry.
"On this trip I invariably take the road through Luton, as I am convinced it is the best and quickest, although perhaps a little longer, than some other routes. On the occasion to which I refer the roads were suffering from the effects of a heavy fall of snow, followed by a quick thaw, then heavy rain. The result was that in many places floods had occurred, and parts of the road were actually under water. However, I had negotiated several watersplashes' without trouble, and was not unduly perturbed when warned by a carter of the existence of a particularly deep one which, he said, I should find a little further along my way. When I did arrive at the particular place to which he evidently referred, I was taken aback to find that another motor lorry had already got stuck in the water, which was over 2 ft. deep. He had got water on his magneto, and had evidently attempted to cross the stream with a rush, but unsuccessfully. I therefore decided to adopt different tactics.
"I first of all made good. use of some water-proof paper which had served as a wrapper for some spare parts. I carefully wrapped the paper several times round the magneto. I then handed a towing chain to the man in the water, who hitched it to one of his front springs. I then drove slowly into the water, hitched up to the other man's lorry, and proceeded, pulling it out after me. "On examination I found that the water had actually been on the outside of my extemporized magneto cover, but had not penetrated it. Now I always take care to have a stock of that paper by me."