In an attempt to decrease my technical ineptitude what are tappets and rockers and what do they do?

I know they're under the rocker covers (jelly moulds) and that every so often they need to be serviced... what does this involve?

Haynes was (typically) unhelpful.

What does 'doing the tappets' involve?

I'm just trying to dispel my long held belief that beneath the rocker covers are little fairies that magically make the engine work...

I've never actually done this job on a 2CV, but I'm planning to have a go when I service the car next month. I found this info helpful:

1.) General

2.) Specific

Haynes is actually pretty good on the mechanics of the job, it just assumes a certain level of knowledge. It's a fairly straightforward job. I haven't got time to go into it now cos I'm off to work soon, but Someone Who Knows will be along in a moment.

wow, cheers smiffy that pfd link is superb.

need to get me some feeler guages...

which I don't have

I respond really well to clear step by step instructions

Well there are 2 types of fairies in there there’s the rockers who hang out in leather biker jackets,
and the tappets who are more of your traditional "little people" and dance a staccato rhythm with their little steel tipped clogs.
when it all kicks off they make quite a rumpus

Michael Flatley is one of the tappets that has made a go of it, he looks bigger on the telly.

Sean

If we get to my rents house to get the yellow car tomorrow then I'll show you on one of the many engines there.

Sam,
if the valve clearances haven't been checked for a long time, I reckon that it's a good idea to retorque the cylinder head nuts beforehand.
Back each nut off by 1/4 turn and then torque to 18 ft.lbs.

Also, it's not really necessary to replace the rocker cover gasket ever time a cover is removed, only if it's showing signs of leaking.

No idea what that warning is about, advising of dire consequences if you adjust the clearance on a valve when it's fully closed.
By making sure that the corresponding valve on the opposing cylinder is fully open, that's exactly what you're doing...

ken

@ Sean,
thanks for that alternative view, needed cheering up as the P~mbr@ has just called to adjust his ETA from 8.45 to 11.00? this evening.
So much for a couple of Friday evening pints...

Let me guess - ETA of 23:00 means ATA of 02:30........

It was ever thus........

OK ...

Remove the front wings.
Find a plasic tub which will fit under the "jellymould" rocker cover.
Undo the 12mm domed nut which holds the rocker cover on.
Wiggle the rocker cover around until it comes off.
In theory, the oil contained within should dribble into the plastic tubs you balanced on the chassis rail, but you may wish to devote some time to looking gormlessly at a spreading pool of oil on your drive / shoes / cat/
Repeat on other cylinder head.
You'll now see all the valves: one inlet and one exhaust valve on each side. The exhaust valve is at the front, and is smaller; the inlet valve is the one nearest the windscreen end of the bonnet. They're operated by the tappets, which are attached to the rockers, which are the cylindrical things with little arms on them.
OK. Now turn the engine over by hand, using the starting handle, until the exhaust valve on one side is fully open (that is, until the valve spring is compressed).
Now toddle over to the other side of the engine, set your feeler gauges to, er, whatever Haynes says (can't remember off the top of my head) and insert them between the valve stem and the rocker arm on the exhaust valve on that side. It should be a firm fit, but you should still be able to move it.
If the tappets need adjusting, use a 10mm spanner to undo the locknut, then screw the tappet in or out using a flat bladed screwdriver. Keep your feeler gauges in the gap between the tappet and the valve all the time.
When the feelers are the required tight sliding fit, tighten the 10mm locknut, being careful not to allow the tappet to move. You need three hands for this bit: one to do up the locknut, one to hold the tappet still with the screwdriver and one to hold the feeler gauge.
Now do the inlet valve. Turn the engine until the inlet valve on one side is fully open, then repeat the above process for the valve opposite.
Then do the same with the other side of the engine.
Then put the rocer covers back on, making sure you've tightened everything up properly.

I wish I'd done step by step photos last time I did this job ...

Hope this helps.