M20/M30 engines
Withdrawal
Attention: If the valve actuator parts are to be installed again, they must be installed in their original positions. To do this, when removing them, they must be folded in the order of installation.
Remove cylinder head.
Remove rocker shafts.
Remove intake manifold.
Compress the valve springs with BMW tool 111 060 and remove cotters C.
Attention; A conventional valve presser can also be used to compress the springs. Depending on the tool used, it may be necessary to remove the exhaust manifold.
Unload the springs and remove the upper spring cup, the pan valve springs, and the lower spring cup.
Remove the oil seals with a special tool. The 791-5 flinger pliers or the 791-2 inertial puller from HAZET are best suited for this.
Pull the valve out of the cylinder head towards the combustion chamber.
Remove the next valve.
Installation
Before installing the valves, check the valve guides, it is possible to grind the valve seats.
Attention: When installing a new valve, lapping of the valve seat is mandatory.
Remove burrs from the contact surface of the valve stem with crackers.
Lightly coat the valve stem and guide with engine oil, and insert the valve.
Lightly lubricate with engine oil and push on flinger A with the appropriate tool D until it stops.
Attention: To prevent damage to the flinger ring, put mounting sleeve H on the valve stem before installing it. If there is no mounting sleeve, glue the contact surfaces of the valve cotters with smooth adhesive tape. Remove adhesive tape after installation.
Insert the lower valve spring cup.
Insert spring and upper valve spring cup. Install springs only with the same manufacturer's markings, the same wire thickness and spring length.
Compress the valve spring and insert crackers. Slowly unload the valve spring, while ensuring the correct seating of the cotters.
Then install the next valve. At the same time, do not interchange the intake and exhaust valves.
Install rocker shafts.
Install the cylinder head.
Attention: The exhaust valves of the 4-cylinder engine are filled with sodium to improve heat dissipation. They should not burn through and be used as a tool (like punches). Explosive! Also, these valves should not just be thrown away. To dispose of them, cut the valves with a hacksaw in the middle of the valve stem into 2 parts. At the same time, do not allow the valve to come into contact with water and then discard it.
Caution: When sodium comes into contact with water, a rapid chemical reaction occurs, during which the sodium burns out.