Procedure:
Locate the car in your work area (garage, etc.) the night before, as the valves must be adjusted with the engine stone cold. You cannot start the engine to move the car before you adjust the valves.
Set the parking brake firmly and block the front wheels. Put the transmission in neutral so that you will be able to turn the engine over by hand.
Note: John Muir (the \"Compleat Idiot\" guy) says not to jack up the car, but he must be a lot smaller than me! I find that it gives me much more working room and makes the job much easier if I raise the rear of the car onto jack stands and remove the rear wheels.
There should be white paint marks on the backside of the crankshaft pulley (the side closest to you) at TDC (there is a notch in the pulley at TDC) and 180o opposite TDC. If they are not there, paint them on with White-out or white paint. Use the straight-edge to locate the point exactly 180o opposite TDC.
Note: Top Dead Center is the point at which the piston is at it's highest point in the cylinder -- compression is the greatest, and firing of the spark plug takes place. The cylinder must be at TDC when you adjust the intake and exhaust valves.
Note: You should also paint white marks at your idle timing point and maximum advance timing point. See the Tune-up Procedure to determine these timing points.
Remove the distributor cap and stow it out of the way. With your fingernail find the thin filed line on the distributor rim; this line marks the firing point to Cylinder #1.
Note: It helps if you have previously placed identification markings on the spark plug wires and on the distributor. Copper wire wrapped around the distributor end of the spark plug wires works well -- one wrap for Cylinder #1, two wraps for Cylinder #2, etc.
Put the 19mm socket or box-end wrench (ring spanner) on the nut that holds the generator pulley and rotate the engine clockwise (forward, the way it runs) until the distributor rotor points to the line on the rim and the timing notch (and paint mark) lines up with the crack in the crankcase. This is Top Dead Center (TDC) for Cylinder #1, where the cylinder fires. Rock the engine back and forth a little bit to make absolutely sure that Cylinder #1 is at Top Dead Center.
Note: If turning the alternator pulley nut does not turn the engine but simply turns the alternator pulley, your drive belt is too loose. You tighten it by remove the pulley nut, the shims stored underneath it, and the rear pulley half, then add some of the shims between the two pulley halves until the tension is within specifications. See our Fan Belt Adjustment Procedure.
Crawl under the right side of the car and locate the valve cover (oval piece of pressed steel held to the engine with a thick, loopy, springy wire).
Before you take the valve cover off, look at its lower edge. It may be cruddy but it should be dry. If it looks like its been leaking, you should install new valve cover gaskets. (Even if only one needs to be replaced, replace both. I always install new gaskets every time I adjust the valves.)
Pry the wire clip off with the large screwdriver -- the clip must be pried off downwards, or you won't be able to remove the cover easily.
Pull the valve cover off the cylinder head. Hopefully the cork gasket will come off with it, all in one piece.
Note: If someone has used some kind of gasket sealer on the valve cover gasket, you are going to have a really fun time with it! More about that later.
Once you have the valve cover off, observe the scene before you. You are peering into your cylinder head. You see the rocker arm assembly, with four rocker arms. There are four pushrods that push on the lower half of the rocker arms, and four valves which the upper half of the rocker arms pushes, opening the valves. When the pushrods stop pushing on the rocker arms, the valve springs close the valves. What pushes on the pushrods is the camshaft, pushing on the solid valve lifters, which push on the pushrods, etc.
Note: The two valves at the very front and very rear of the cylinder head are exhaust valves, and the two inner ones are intake valves.
The two forward-most rocker arms control the intake and exhaust valves for Cylinder #1. With the cylinder at TDC, they should both be closed completely, and in the same position. If one is in a different position than the other, you are not at TDC for that cylinder, so go back over the above steps and find out where you messed up. Wiggle the rocker arms. You should feel a little bit of movement. You are going to be adjusting the clearance between the rocker arm and the valve stem to 0.006\", which is a pretty small clearance. (0.006\" is the proper clearance for both the intake and exhaust valves.)
Adjust the #1 exhaust valve first (it's the one closest to the front on the right). Push the rocker arm in at the bottom to make sure the pushrod is fully seated in it. Slip the 0.006\" feeler gauge into the gap between the valve and the upper end of the rocker arm, underneath the adjusting bolt.
Note: Make sure you slide the blade of the feeler gauge in straight, or you will get a false reading. You should be able to feel it slide through the gap with only a slight bit of friction.
If the 0.006\" blade won't go into the gap, try the 0.004\" blade. If it's hard to push through or grabs, then the valve is tight and requires adjustment. If the 0.006\" blade just falls through the gap with no friction at all, you have a loose valve, and it likewise requires adjustment. If the blade slides through the gap with just a slight resistance (easy sliding), the valve is adjusted correctly.
If the valve is either too tight or too loose, you've come to the fun part. Observe the valve end of the rocker arm. You will see what looks like a screw surrounded with a 13mm nut. The nut is a locknut, so what you do is get your 13mm box-end wrench (ring spanner) on it and loosen the locknut. Be careful--make sure the wrench is firmly on the nut; skinned knuckles abound at this point. I sometimes have to break the lock nut loose with a 13mm socket and ratchet. You only need to loosen the nut a quarter turn or so.
Note: If you
