I'm planning to install a new euro cam in my 1970 280SL. I've pieced together a set of steps to do the job from the old yahoo site and from comments Joe Alexander as offered. I would appreciate those that have done this job taking a look at this and offering any insights or comments. Thank you. I have incorporated the comments from Steve, Naj and Joe in the instructions below.
Change 280SL camshaft on an installed engine
Do this job while the engine is cold as you will need to do a valve clearance adjustment as soon as you are done as well as retorque the head
1)Release the pressure in the cooling system by backing off the radiator cap. You may also wish to drain of some coolant, but it is not necessary. It is suggested to remove 50% of the antifreeze in the engine to make sure antifreeze cannot find its way into the cylinders.
2)Remove spark plugs
3)Remove throttle linkage and valve cover
4)Align as perfectly as you can the number one mark which is a notch on the washer mounted in front of the cam with the arrow mark which is cast into the first cam bearing pedestal. Make certain that number one piston is at TDC and the rotor on your distributor is pointing to the small notch in the outer rim or the number one spark plug lead in the distributor cap. This is important so you can reinstall the chain sprocket into the exact same position from which it was removed.
5)Secure the timing chain to the sprocket with a tie rap to make sure the sprocket does not change position in the timing chain. Suggest that rags be stuffed in and around the timing chain opening to prevent and items from falling down inside the engine. It is very important to mark the position of the cam sprocket and camshaft. Use a sharpee or white paint.
6)Remove the cam oiling tube
7)Remove all rockers before unfastening any head bolts. This will prevent up force on the camshaft, preventing any damage to cam supports. Remove the rocker arms and number them so they can be returned to their original position. Remove by inserting a 5mm allen wrench in the rocker arm hole over the ball stud and then lifting allen wrench and rocker arm over the ball stud. The cam forces the valve to compress, swing the allen wrench to one side and its off! To install, place the end of the rocker on the pressure pad and lift the allen wrench. Swing the rocker into position and lower on the ball stud! If you encounter any resistance as the valve is compressing, you may have to rotate the engine slightly since the valve may be contacting a piston. Also mark the orientation of the pressure pads on the valve top in relation to the rockers. You will notice that the wear mark on these pressure pieces is off-center. Exact orientation during re-assembly is best but not critical. In this way, wear patterns will be again matched, making the valve adjustments more precise and longer lasting and a quieter engine valve train
8)Remove the head bolts that hold the metal brackets for the valve cover. Once you remove the brackets and the oiling tube, reinstall the head bolts and partially torque them. This will hold the head in place and maintain a seal as you remove the bolts that fasten the cam bearing pedestals.
9)Remove the large 22mm nut and washers on the front of the cam which holds the cam sprocket in place. Remove the sprocket from the front of the camshaft. If the chain is loose enought the sprocket may be removed by sliding the cam to the rear and slipping the sproket off the camshaft. If the chain is tight you may have to locate the master link (assumes your timing chain has been replaced) and remove it to separate the chain. Please remember the master link has 2 figure 8 side links and a locking clip. One side link is located in the center of the master link and the other on the outside under the locking clip. Remove the cam and the cam bearings. Do not forget that there is a small 10 mm nut which also holds down the cam bearing pedestals. Keep cam bearings and bolts in sets and reuse them in the same locations. The rear bearing is removed to the rear. The other three bearings are removed to the front of the camshaft.
10)Reinstall the cam. You must realign the notch on the cam washer and the arrow on number one cam bearing pedestal. Tighten down the cam bearings to spec. Install the cam and holders on the head and oil it and its holders up well. Remove the bolts that hold the metal brackets for the valve cover. Reinstall the cover brackets and torque to the first torque spec
11)Torque all head bolts to specs in three passes. Turn the cam during each pass. When finished, you should be able to turn the cam by hand. Some resistance is ok.
12)Connect the timing chain and cam sprocket. Turn the engine by hand in the normal direction of rotation to double check the timing marks. Install the rockers next if everything is ok. If you have to remove the cam stands to shim , only unloosen the head bolts that are needed or you may damage the head gasket. You may have a difficult time installing those rocker arms where the cam lobe is pushing on the mating surface, i.e. the cam lobe is pointing down. Since you now have the sprocket installed, you can turn the engine over by hand to orient those rockers in a more favorable position. Then turn the engine until the notches in the cam bearings and the distributor are aligned to make certain nothing has slipped.
13)Retorque the head to specs and do a valve adjustment.
14)Retorque the head after initial warm up and again after 500 miles. At 500 miles adjust the valves
