FORD' VAN POINTERS.
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By R. T. Nicholson (Author of "The Book of the Ford ").
THERE WAS a time when I believed in taking the silencer apart and brushing out the accumulated sot from its " innards." I used to do this, say, every ,Ijet0 mites, and was regularly rewarded by greater power after the operation..
But it is a pretty big job to take the silencer apart and Put it together again, so I looked for an easier way of getting the same result in improved running. Here is that easier way :—
299.-Scavenging the Silencer.
Tap right along the exhaust pipe and then over the silencer with a light hammer. Cover as much of the surface as possible with your taps, the idea being to dislodge the soot inside. You can tap pretty' hard on the exhaust pipe, but do not tap the silencer hard enough to -dent it.
The soot loosened by the tapping will be blown out by the exhaust when the engine next runs. I do not claim that this plan is as thorough as that of taking the silencer apart, but it is quite effective, and I am pretty sure that you will find your engine running better after you have done the job—especially if the exhaust pipe and the silencer werehadly sooted,. . so that there was a good deal of back pressure. Of course, you have to get under the van to do this job, though, if you drive a new model Ford, you can cover most of the ground by lifting up the footboards. . You will then be, able to work from above, instead of frOra below. It is one of the advantages of the new model that you can now do a good many little jobs "from above," instead of from below on your back.
Very few drivers realime the importance of keeping the exhaust passages—that is, the exhaust pipe and the silencer—free from accumulated soot. If they are not GO kept clear, back pressure against the, engine will be set up, and that, of course, means .much loss of power, to say nothing of excess petrol consumption, over-heating, and other evils.
It iloc-.s_ not do to let. the Soot go on accumulating for ever. I have shown you an easy way of loosening it and getting rid of most of it. As a sooty chimney won't draw, no a sooty engine . won't pull. Same thing in a different way.
300.—The Foot Switch.
.I have been asked whether any harm is done if the foot switch is trodden on accidentally when the engine _ is running. (I refer, of course, to the starter switch on the new model.) . Being where it is, it is pretty certain to get trodden on at times, and some drivers think that it would be better if it were placed somewhere else. Most power-starter systems have the starting switch on the dash, where it is. depressed by hand, and cannot get trodden on. While I do not believe it is good practice to tread on the foot switch., and so to throw the starting pinion into gear with the. flywheel, no particular harm is done by an occasional little mistake of this kind. The starting pinion is thrown into enga,gement with the flywheel teeth, it is true, and there is just the Slightest grating at the moment of engagement ; but the rotatmg flywheel at once throws the pinion out, and the clashing is very slight. Still, as T have said, it is as well to keep the feet .awayi from the foot switch—'if for no other reason than that there is loss of battery current every time the switch is depressed.
301.—Running on Three Cylinders, •
There are times when the driver has to get home on three cylinders. The journey in such circumstances is a jerky business, and it is a mistake to run any distance with one cylinder cut out, because it means a considerable strain on the transmission.. Sometimes however, the thing has to be cl.orte,, simply because the fourth cylinder cannot be got to fire by roadside attention.
In such circumstances, you will reduce the strain on the mechanism if you do as follows :— First find out which cylinder is faulty. There are various ways of doing this, but perhaps the simplest way is to have the engine running, and then to lift each coil unit in turn, replacing each in position after lifting, if its lifting, slows the engine. The unit which, when lifted, makes no difference to the running of the engine is the one corresponding with the faulty cylinder. Keep that unit lifted by packing under it with a wa.d of paper. Next trace, from the back of the coil that you have just lifted, the thick high-tension cable to its sparking ping. That sparking plug will, of course, lie in the faulty cylinder. Remove that plug. You will now find that the van will run much less jerkily than it would do if you had not done this. Do you see why ?
Removal of the sparking plug has relieved compression. Much of the jerkiness that arises when the engine is running on three cylinders is due to the resistance of compression in the cylinder which does not fire. Not only does that cylinder not help to turn,' the engine—it positively resists the turning of the engine. If you take the plug but, you cut out that resistance, by making a hole in the cylindcr—the hole that the sparking plug previously occupied. So you get comparatively smooth running—not, of course, as smooth as if all four cylinders were firing, but much smoother than you would expect.
But why lift the coil unit corresponding. with the faulty cylinder? Ha 1—that is rather a nice point. You lift the unit and pack paper under it to prevent the low-tension current (from the magneto or battery) passing through it. In any event, as the cylinder in Question will not fire, the coil unit in question cannot
. do any good. tut if were down in its regular working position, the low-tension current might still pass, though the high-tension spark did not appear at the plug. Now, this might quite well mean a serious internal strain an the coil unit. Any interruption in the high-tension circuit when the low-tension circuit is working means 'strain on the coil. So we lift the coil to throw the low-tension current out also.
Of course, the lifting of the coil unit does not contribute to the smoothness of the running ; it is the removal of the sparking plug that governs that. But you do not want to strain your coil unit when running in such circumstances. Therefore, lift as described. When back in the garage, the real cause of En trouble must be located and removed.
302—A Few Driving Hints.
You get round corners most easily if you use the oariaber of the road properly. For instance, in taking a left-hand corner, get your van well over to the left of the road, so that the right-hand wheel, will lie higher than the left. You will then find yourself swinging round much more easily than if you took the corner on the crown of the road. I should like to go on to say that, in taking a right-band corner, you should get well over to the right of the road; .butthere is some danger in this, unless you can see well round that said corner. The point that I want to bring out is that you should make use of the road camber to direct your van. You can do so even when it is not a case of cornering. For instance, when the road curves, you will find yourself running mach more easily if you let the camber help you along the curve. This is, of eourse, a tip not for the traffic driver but for the driver on the open road round. The traffic driver has to drive where the road is clear—not where it best suits him. The reason why it pays to make use of the road camber is that such use makes little call on the differential. There is no differential in a railway' locomotive; therefore,. they camber the corners, raising the rail on the outside of the track. For the same reason. you can get round a road corner if you lower your inside track and raise your outside track, without calling your differential into play—always providing that tire raising and lowering are sufficient. True, the differential does not use up much power but it uses up some power, whenever it comes into ; play ; and it comes into play whenever it becomes a question of driving one bath wheel faster than the other—in cornering, or curving ; but the better use you make of the camber, the less use you make of the differential. So you run that much the more easily. The point is of special importance in hill-climbing. If you are going up a steep hill which the van will only just climb in the most favourable circumstances, you will find that it makes quite a difference whether you use the camber or not. Irthe hill is straight, run the van right at the top of the camber—on the crown of the road. If it curves to the left, run it slightly to the left of the crown; if it turns to the right, get on to the right Bide of the camber. You will soon be able to judge how far you ought to get over to right or left if you study the point. You will get " horse-power sense." tvery time you can, by this plan, prevent the differential from coming into play, you will save horse-power, and will climb hills so much the more easily.
Another Hill-climbing Tip.
You can often " steal " up the last few yards of a very steep hill by closing the throttle, instead of continuing to run with it full open. This may seem strange, but it is true, Try it. What happens, I think, is this : Your engine gets pretty hot in running up a long, steep hill. The ingoing mixture is expanded a great deal, and compression, therefore, gets a bit too high to be comfortable for the engine. By closing the throttle a little, you reduce the amount of mixture admitted to the cylinders, and so lower the compression. Compression is simply a sprat to catch a whale. If you use a whale to catch a whale, you do not do much good, and if you use a whale to catch a sprat you are B2 well out' of Pocket! In other words, compression always uses up some power from the engine momentum ; but if it does not use too much you get more power back from the explosion under compression. If, however, your compression gets too high, you do not get the power back in the explosion ; you lose some.
That is why the partial closing of the tkrottle at the top of a hill, when the engine is very hot, may help you over the top. I
303—Carburetter Control.
I have just seen a home-made gadget which strikes me as being quite a good thing. Drivers of the new model will know that the carburetter control on the clash is none too get-at-able. It lies deep down below the instrument board, well out of sight.
The gadget in question consists of an upward extension of the carburetter control, so that the adjustments can be made from the instrument board, instead of from the dash.
The extension consists of a rod passed through the instrument board, in which a hole is cut for the purpose near the air throttle centre! button. The lower end of the rod si turned over into an eye, go as to pass through 'the loop of the standard control. The top end can be similarly turned into a loop ; or a brass disc can be attached to the rod after the manner of the old carburetter adjusting rod head, a file mark being made on this disc to indicate the normal running position.
As the new rod is turned, bv means of its loop or disceathe lower (standard) rod is, of course, also turned, for carburetter adjustment. With the new adjuster, you can both see and feel what you are doing, and keep the carburetter setting 'just right "—and it is very important that you should keep it "just right" for efficient and economical running.