Car Engineering and physical laws


I was always taught that physics was an exact science.  What goes up must come down, for every action there is an equal and opposite reaction, similar magnetic poles repel, pressure is equally distributed in a closed vessel, the speed of light is absolute, e=mc2 and all that kind of stuff.  Well, it’s not.  If you ever want to disprove physics as a science, then buy a car.  They do not obey physical laws.

I have always considered car electrics to be a black art.  Take the battery, for example, and I am sure you have all experienced the following.  You have a perfectly good battery which is just over 12 months old.  In your mind that’s almost brand new.  In fact, you can even remember how much you paid for it, so it must be very new.  And then one morning it won’t turn the engine over.  It worked perfectly yesterday, and now it won’t, or doesn’t want to.

You push start the car and run it for half an hour, as you suppose you must have left the headlights on, or something equally as explicable.  Turn it off, and hey presto!  It’s as dead as a dodo.

If you are really into masochism, you then borrow your mate’s battery charger and leave it on all night.  Triumphantly you remove the cables and jump in.  It doesn’t work.  Perfectly good one day, completely cactus the next.  Explain that one, Mr. Einstein.

I haven’t finished with electrics yet.  There’s the great little device called “the coil”.  This electrical marvel delivers high voltage to the spark plugs and does a sterling job until one day, it just doesn’t deliver.  No warning.  It just stops working and is then quite useless forever.  You cannot resurrect it, coax it back into life or anything.  Its only use is as a missile to throw at soi dogs.

Another bit of engineering that defies physical laws lies in the universal joints in the propeller shaft.  A kind of metal X with case-hardened caps filled with rollers.  Despite all the greasing in the world, these things would always seize up, and you had to pull it all apart.

The Owners Manual made it look easy.  (Those were the days when the manufacturer actually allowed you to touch the car.  These days your warranty would become null and void and you would probably be subjected to some kind of exquisite electro-torture.  Tomorrow you will be shot if you open the bonnet.)  But back to the manual, plus pix of some chap in a dust coat.  “Tap the yoke lightly and the bearing will appear” was what the good book said.  Not one solitary word as what to do when the bearings didn’t appear – and they never did.

No, the tapping physical law does not exist.  You have to get the biggest cold chisel you can and split the casing, and by the time you have thoroughly butchered it, then the bearing will appear – in bits.  “Tap the yoke lightly” indeed!  Physics be damned!