FORD VAN POINTERS.
Page 23
Page 24
If you've noticed an error in this article please click here to report it so we can fix it.
By R. T. Nicholson (Author of "The. Book of the Ford ").
IASKED where the sixth mavietizing coil could be found in the new model Ford (in addition to the four in the coil box, and the one in the horn). The answer is that there is one—there are, indeed, two—in the cut-out. '
356.—That Question to the Brainy.
The cut-out acts thus:—
When the generator begins to deliver current, that current flows from the generator terminal through the base of the cut-out, and round a coil, passing thence back to the generator.. This is known as the voltage coil. The coil runs round a pole piece of soft iron, which is magnetized by the passage of the electricity, so as to pull towards the pole a hinged arm, bearing a contact piece. This contact piece is thus pulled into touch with a fixed contact piece, and the generator current. then flows through both contacts, and through a heavier, coil, on its way towards the ammeter, and to the battery. This' is the cut-in action—which always takes place when the engine is started, and the ammeter registers " Charge:" When the engine slows down far enough, and the ammeter ceases to register " Charge," there is cutout action. The object of. the cut-in is, of course, to connect up the generator with the battery and the object of the cut-out is to disconnect the battery from the generator. (Without this last action there would be chronic drain on the battery current whenever the engine stopped.)
The heavier coil—the current coil—acts as a magnetizing coil after the cut-in connection has been established, and so keeps the contact points touching. So the flow from generator to battery is continuous as long as the engine is running fast enough.
When the cut-out action takes place, it is because the battery current tries to get back to thei generator (through the closed points), but is met by the generator current trying to get through to the battery. There is, therefore, a point where the two currents balance, and the magnetism of the current coil then " comes unstuck," and the points separate, so that there is no longer any connection between battery. and generator, or vice versa.
357.—The Red Dragon Oil Filler.
This is a, useful fitment. It is really an oil funnel which can be attached permanently to the Ford engine. Any user can fit it. It is solidly made, and has no loose parts to rattle or wear loose.
The advantages of such a fitment are obvious. Your " target,' instead of being a small filler-pipe is a huge gape, so that you score a bull's-eye every time, and every drop of oil goes into the engine. So you not only save oil, but you keep your oil off your ignition wires, your timer, and your fan-belt. It is fitted with a searching strainer (really needed). With it installed, you can slop it in any old how '—even in the.. dark.
Price 10s. (l08. 6d. carriage paid in the U.K.). Manufactured by the patentees, Messrs. Meekan Rose and Co., automobile engineers, Bristol.
358.—Foul Plugs and the Causesof Pouting.
Why 'in the world I have suddenly been snowed ruder with correspondence about foul plugs, I do not know. Stop a bit. I'm not so sure that I cannot guess. At the time of writing, " summer is a comin' in," and oils that are suitable for winter use are by no means the beat for summer use. Maybe some of my correspondents have been using too light an oil, and that is the reason why the plugs have had more than their share of. lubricant.
But when the question of ". dirty plugs" is raised, I wish my correspondents would'distinguish between oily plugs and sooty plugs, for the cause of troabie may be entirely different in the two cases. Oily plugs are due to oil getting up into the combustion chamber ; sooty plugs are due to imperfect combustion of the mixture. Either may, of course, cause rnis-firing, but it is. important for the doctor to know just what the patient's secondary symptoms are.
Over-rich Mixture.
When your plugs, get. what may be called "dry carbonized," you, may be pretty sure that your mixture is over-rich--that you do not cut down your spirit to the proper point. This is particularly true when you use benzole. With a new model Ford there is a temptation for the driver to overlook the carburetter hajustment on the dash, for it is tucked .away out of sight below the instrument board—and " out of sight, out of mind." The setting of the carburetter adjustment which best suits the start by no means suits all-day running. When the engine is well warmed up, the carburetter adjustment ought to be turned down until the charge will just not misfire. I rather like driving an engine that tends to pop back, because then I know that I am not fouling my engine.
Of course, you will always get some sooting of your plugs, do what: you 'will; but you ought not to have the trouble described by one correspondent, who has to clean his plugs at least once every 50 miles. My own rule is to give one plug a paraffin
'bath • once a week, swilling out with petrol afterwards. It is a good tip to lay the plug in paraffin all night, swilling out in the morning. Thus, each plug has a bath once every four weeks (which would be a pretty poor allowance for the driver; by the way !).
Oily Plugs.
, Oily plugs are another story. Oil gets on to the plugs for all sorts of reasons, of which I may name the chief, as follow :— (1) Over-oiling.—Most drivers carry their oil level too high. For the first 500 miles in the life of an engine I would deliberately carry the level up that of the top cock, knowing all the time that I was over-oiling. I should do that seemingly silly thing, because
the working parts of a new engine ought to run simply soused in oil ▪ That
helps them to run in. But, after 500 miles' running, I should begin to cut the level dawn to, say, half-way between the two cocks. After 1,000 miles' run
ning, I should lower it to near the level of the bottom cock. I should not, of course, expect to drive the van for 75 miles without more oil, but I would first.. give it a 25 miles' run and then turn on the lower cock to see if the oil would still flow. If so, I would let the van run for, say, another 10 miles, and then test again, replenishing with a little oil—a pint or so—till the oil did just comfortably flow—not merely drip —out of the bottom cock. I will say more on this point presently.
(2) Unsuitable oil.—Your engine ought to drink a heavier oil in the summer than in the winter. A clirtY oil
ranks as unsuitable oil, net so much because it is dirty as because dirty oil is pretty sum to be stale--,:worn out—and stale oil is as thin as water.
(3) Worn piston rings, pistons, or cylinders.—Not to be suspected as guilty of plug fouling unless the engine gets overheated, when running and develops poor power.
(4) Downhill " coasting " with ignition switched off.—This sucks up the oil past the piston rings and splashes it on to the plugs. The practice is quite harmless when an extra air attachment: is, fitted, because then no vacuum is set up inside the combustion head to suck on the oil supply round the walls of the cylinder.
Soot.
Now, let me ge back on myself and deal, first, with the nature of soot on plugs ; and, second, with that over-oiling question. Plugs will soot, but there it, soot and soot. It your mixture is right or nearly so—as nearly so as you can get it without "extra air "—the soot on your plugs will have, a yellowish tinge, and be dry and " bloomy "—not black and glossy. A black and glossy dry soot indicates the habitual use of overrich mixture
The Ford is properly oiled when the oil in the crankcase is circulating. It is over-oiled when the oil is heavily splashed about by the.flywheel as well as circulated. Most of the. splashing that goes on in the Ford engine should be done by the big-ends. The flywheel, however, has its job, too, for it canies the magnets on its rim, and the magnets pick up little loads of oil for delivery into the funnel near the top of the flywheel as each comes round. It is.. the .magnets that start the oil circulation—not the flywheel itself. The flywheel makes a lot of fuss in the oil sump, but the magnets are the workers.
Now, if the oil level is up to the height of the lower petcock, the magnets will dip all right and C24 will each get its little burden of oil. That is all that is, needed. If the level stands a lot higher, everything within reach gets soused—particularly the cylinder walls,whence the oil gets carried up into the combustion chamber by the rising pistons. So the Ford engine gets all the oil it needs (once it is well run in) when the oil level stands at that of the bottom cock or a little higher. If it stands much higher, the surplus simply gets burnt up quickly, and passes out as smoke through the exhaust—except for that which settles down as carbon in the combustion chamber.
Therefore, the oil level ought always to be " right there "-I-down near the bottom petcock...But if you started with it right there, you would not run many miles before it got below that level, and if it got far below that level, the big-ends might quite well begin to melt. That would not do. So, as you do not want to run risks, and as you do not want to be hopping down every few miles to supply more' oil, you carry the oil level a bit higher than the bottom cock.
All the same, if you want to economize in oil and prevent carbon forming too quickly in your engine, you will act on the " little-and-often" principle. I know that most drivers prefer to oil once a day, no matter what the run is. It is far better to oil at least once every 50 miles and to reduce the quantity, supplied. I would even go so far as to say that it is good practice to oil once every 25 miles and cut down the quantity " per time still more. You will save oil, get sweeter running, and less carbon by so doing.
Be Wary.
IN ow let nobody come back to me and blame me for a burnt-out big-end. Unless you are going to be careful and watchful when reducing your oil supply and your oil consumption, you had better stick to your dirty " chuck-and-chance-it " plan. But do not tell me that the Ford is a dirty engine because you get a lot of oil and carbon in your combustion chamber with the " chuck-and-chanceit" feed. It is you who are dirty, not the Ford engine.
"One word more, and I have done." Do not suppose that when your engine is running your oil supply in the crankcase remains obediently at the level where it was when the engine was still. -It does not. It gets splashed by the flywheel in any case, and so the level gets lowered, though the splashed oil is, of course, always trying to flow back to restore the level. C4ranted that the oil started , at a level slightly higher than that of the bottom petcock, there will be enough oil in the sump to feed the magnets for quite a time to come.