Renault clio 1993 piston liners

The figure you are asking for isn't generally included in the data and much depends on the engine design and the sort of work you are carrying out.
Mostly the specs for the block and pistons and cylinder head are given separately and if they are adhered to the piston to valve clearance is never an issue.

Mostly diesel engine pistons are graded for height so the correct protrusion above the cylinder block face can be adjusted. With a wet-linered engine the liner is adjusted by inserting shims to also have a small protrusion above the block face.

After machining the face of a cylinder head the height of the valves above or below the head face should be checked against specs and will often require lowering by cutting the valves seats further into the head.

Engines that do not use height graded pistons tend to use a selective thickness head gasket.

I am on the wrong computer to offer you any specs but any good data book or repair manual will provide them.

You are right. Petrol was put in your tank causing your Pistons to over heat.Petrol does not have enough oil in it to lubricate the cylinders causing the motor to seize.Your lucky it didn't blow a hole in the Piston.This is a common problem especially when your old car was running on Petrol or If a friend borrows your car but usually they have a note on your dash or where the gas cap is. The engine will have to be over hauled or replaced with a used one. I hope this helps you out.

the liner sits 1mm above the deck of the block and the piston top is level with the top of the liner.

You will have to give the make and model of the engine but generally it is the amount that the liner protrudes above the block to produce an effective seal with the head. Too far out and the head will not seal properly on the head gasket and not far enough will allow the liner to move with the piston and fail. It applies to wet liners or semi-wet liners mostly

You need liner kit with shims between head and block

On a Renault the fuel pump relay should be under the bonnet next to the battery (black box).

Must be the old gear driven style. Gears are worn out. See about one from the salvage yard.

im afraid to say that yor piston rings are worn and will need a engine rebuild , you could try and put a thicker oil in 15w40 or 20w40 if you can source it . hope this helps

How much mechanical ability do you have? Replacing the head gasket on a 5 is not an easy job, and if you have water in the oil, you prob have compromised the main & rod bearings. Water & oil on the bearings makes them wear out rapidly. Plus, if you take the head off (don't pull it UP, leave a corner bolt in loose and PIVOT the head on the dowell pin, that way you will not pull up the liners), if you don't, you will unseat the piston liner seals, then you have a whole new problem to deal with. If you really want to do this, you need to remove the cyl head, and then take it to a machine shop to check the straightness of the head mating surface, and possibly the block. Then hope that the liner seals are not compromised when you put it all back together...
Overheating Renault engines is unfortunatly quite expensive.
Sorry, I do not have the torques specs.

Replace the car. get an 1989 peugeot 205, great car, cheap and stays for a long time, oh and 0 problems i had it for a 3 years.