• FORD VAN POINTERS.
Page 25
Page 26
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").
THERE is a difference between a, setter and a pointer. A sett. r is one who sets difficult questions ; a pointer is one who tries to answer them. (That's me!)
I have picked out some of the letters which I have recently received (and which I have already answered through the post) as being, for one reason or another, of interest. I print the answers which I have sent, in the hope that they may prove of interest.
498.—From a „Garage.'
I thought I had a lot to learn from any man who runs a garage, but there is one who runs a garage who thinks that he has something to learn from me.
The query runs:—
"We are up against, it with regard to tuning up a, Ford, 1914. The trouble is that, whilst the engine will throttle down and run quite slowly, and will run on any one cylinder, in the garage ; it will not run evenly on top gear at speeds under 20 miles per hour. At over 20 miles per hour it will climb a hill of 1 in 13 on top easily, engine running perfectly. A new set of wires and sparking plugs have been fitted, carburetter examined, all controls are without play, needle valve has slightly less than one full turn open, magnet plug is clean, coil blades have all been adjusted. Brakes appear to be in order.
" Any information as to the cause of trouble (engine is jumpy on top gear under 20 miles per hour) will be appreciated."
Reply.
I strongly suspect that your magneto output is poor. This may be the fault either of the magnets or of the stator coils—probably the latter. If it be the magnets that are at fault., it is because they have became weak. If it be the stator coil assembly that is at fault, it is almost certainly because the coils are short circuited, not necessarily through foreign matter from the oil supply but more likely through insulation failure. Either of these troubles . would have precisely the effect you describe. This is because when you have good speed on your engine the voltage of the magneto output increases to a point :where you get enough current. You say that the engine runs quite slowly in the garage, and perfectly at the same time; but if the r.p.m. were counted I am inclined to think you would find them more than they are when it falters on the hills.
To determine, in the first instance, whether it ii the magneto that is at fault, put. a battery into commission and see if the same faults are developed in the same circumstances. If not, suspect the magneto.
There is another trouble that might cause the symptoms in question—looseness of the flywheel. This would give excessive gap between magnets and stator on hills. So long as speed of revolution was maintained, the current might be sufficient to generate a spark ; but directly the speed fell off, the excessive gap would weaken the magneto output to such an extent that the spark would. fair.
499.---A Curious Case.
"The glass window of the ammeter on my Ford (1920) has lately got a bad habit of getting hot—really hot. The glass blurs and gets misty with heat from the inside, so you cannot touch it with the fingers. After running a mile or two a stop has to be made to allow the glass to cool, or it would, no doubt, smash. The ammeter shows charge all right. There does not appear to me to be any short or wire crossed. What is the reason.? Can you say?
What What I Said.
his case of an overheating ammeter was new to me: I had not come across it.before. (Seems to me there might be money in something of the kind for domestic use—something with a motto attached to it—(" Keep off the glass.")
Seriously, however, I told my corresponcleet, that the ease was one for . expert local examination.. Evidently the ammeter is in some way acting as a resistance.Of course, every ammeter offers s-ome resistance to the passage of current, or it would not "am," but it ought not to absorb more than an infinitesimal fraction of the corrent passing through it—certainly not enough to make it get percepinioly
warm—let alone hot; and it evidently was getting let-alone-hot !
My suspicion is that the generator has been producing an excessive charge, which the ammeter is incapable of registeringefor some unknown reasonperhaps because the charge is 'beyond the limits of its scale ; so that, although the poor thing does its best, it is not big enough for its job.
A fault of that kind ought not to be allowed to go on ; indeed, no ammeter fault ought ever to be allowed to go on. Neglect of any kind of warning it gives is bound to spell trouble..
One general warning : Whenever electricity turns into heat at. any point—except at the plug points— worry until yciu have found out why ; and cure the ,rouble.
500.—Oil and Moil.
" I bought last March. Up to about 1,700 miles, her consumption of oil was less than one pint per -7.00 miles; and she did not smoke. Now she requires one pint every 30 miles and smokes furiously when the engine runs at rest. I went to a Ford depot, and they advised new top piston rings, oversize, which was done. The nuisance is as bad as ever after 300 inilee' trial. Moreover, I have to creep up long hills on low that I used to tly up on top. I have had her decarbonized and valves ground in. There is.no leak underneath to matter. The brakes and transmission bands do not bind."
Rings Out !
I replied that all the symptoms seemed to point to piston ring trouble—not • necessarily limited to the top rings, but related to all rings—especially the bottom ones. . Carbonization of rings in grooves would have the effects described. I wrote:— " I suggest that all rings be replaced. The two tap rings guard the compression; the bottom ring is really a wiper,' to prevent too much oil from getting up towards the combustion chamber ; it is also an aligner, but in this case it is as a wiper that it is needed most.
." If you have often had your lower transmission cover plate off (for scavenging), it is possible that you need a new gasket there, the present one having been squeezed too thin. This would result in the raising of the level of the sumps under the big-ends and undue splashing." • I have since heard that the smoking trouble has altogether ceased since my advice was .carried out, although full power has-not yet returned. I suspect it will, however, when those new rings have been run in.
501.—Another Odd Case.
And another case of things getting "hotted up," as my good cook-(and she is a good cook!) calls it.
" The rear off wheel of my 1916 Ford gets hot after
fese miles' run. (I-should have said the tyre.) This wheel has already burst me six tyres. I always stop on the road after a few miles and feel the tyres. I always find the off rear tyre hot, while the Others
are cold." .
Then follow a few nice appreciative" remarks as to what I have done in my hort life for the Ford owner ; but I am too modest to repeat them here.
In this case the over-heating of one tyre does not seem to suggest any money-making invention. Nobody wants hot tyres. I wrote :—
" I strongly suspect that your differential is not ii orking properly and that there is no really independent action of the rear wheels when driven. It should he possible to jack up the back of the van with one wheel off the ground, and then to have that lifted wheel turning when the engine runs, the other (the one on the ground) being at rest. If, however, you make this experiment, sketch the front wheels well, or, it the differential is faulty, you may find that the
tee2 car will try to run forward directly the brakes are taken off. What I suspect is that you will And that both wheels have to turn together, and that neither will turn independently of the other. This should not be. The result of that state of things would be that the van would tend to run permanently in a straight line and that every departure from that straight line (even slight) would result in one of the wheels skidding over the ground instead of turning over it.. That would account for the heat of the tyre.
" When both wheels are jacked up and one is turned by hand, the -other ought to revolve in the opposite direction. Does it? "
A Budget.
One correspondent sends me six long questions in an eight-page letter ; arid I am proud of the fact-that I replied fully to every one of the queries, as follow :-
(Hold ! The (!.M. won't !—En.) All right. Next !
• 502.—More Heat.
There seems to be a heat wave about just now, as witness:— " I have encountered a strange experience, burning out the cut-out on the 1921 model Ford, and I should be greatly obliged if you could assist me in any way of overcoming this difficulty.
"My ammeter reading at about 75 to 20 miles an hour is 20 amps. ; now, in your book of "The. Ford and its Electrical EqUipment," you say 10 to 12 amps. aei the .maximum. . I have been to a Ford service depot, and they tell me that I have a good generator and that I am quite correct ; in fact, they say e it's a real 'un,' and yet I suffer from burnt cut-outs (this being my third new one) and also burning out of the side light bulbs, especially the off-side lamp. I have made no adjustment of the third brush, as I have left this to the people at the Ford service depot."
What I Thought..
I said what I thought—as follows:—
"The man who tells you that a 20-ampere charging rate is good ought to luunly. better. It is that said rate that has burnt out your cut-outs. Presumably, it is your voltage coil that has gone. I don't wondet. at it. If it took 20 amps. for long I should be surprised. The efficiency of a generator is not to be measured by excessive output, but by its delivering current within Certain narrow limits. You do not get greater efficiency, but suicide, at 20-amps. Whilst I will not gc.so far as to say that this heavy amperageis responsible for the burning out of the side light bulbs, I am by no means sure that it is not, because the. excess amperage might, I think, find its way to the lamps. Get that third brush adjusted right away."
503.—A Question that Goes Unanswered.
"What causes a noise when changing the speeds or gears: would same be doing any damage to the transmission, would it be likely to cause an axel to break? would it be caused through too much gas or not enough,' on starting up, it occurs when changing on a slight incline, sometimes it does not occur, we hope you will understand what we mean."
Anybody can reply to that simple question—anybody but myself, I mean.
504.—An Easy One.
" My engine backfires when I crank her with the spark advanced. What ought I to do?" The answer is in the alternative: Either—
(a) Don't do it.
(b) Live near a hospital.
Of course, I did not really send that rude answer: it was a case of "'words to that effect."