Socket Size for Crankshaft Pully Nut 1979 E21 M10

[csvnevada]

Trying to identify the socket size for the M20x1.5 crankshaft pully nut on my 1979 BMW USA E21 M10 4 cylinder. If I put a socket and breaker bar on the hex nut I was hoping to be able to turn the crank and cam for adjusting the valves. Not sure if this is possible due to the fan and radiator being in the way unless I remove the radiator. Is this practical? My car does have the double pully for A/C so it makes it a little more of a clearance issue between the pully and radiator.

[Jeroen]

With a bit of luck removing the fan will be enough. On a M20 the socket size is 27mm but that is with a M18 bolt, with a M20 bolt it is most likely 30mm.

Alternatively you can put the car in 1st gear and with the spark plugs removed it should be fairly easy to advance the engine by moving the car a little bit forward.

[csvnevada]

Jeroen
Thanks for the good advice. A 30mm deep socket seems to work with the deep pully on my early 1979 E21. Pretty tight but if I loosen and drop the fan shroud should be able to easily turn the crankshaft clockwise without having to remove the radiator and/or fan. I have a sloped driveway so was trying to find an alternative to putting the car in 1st gear, pulling plugs, etc. Was trying to locate the Baum single row chain engine turning bar tool but they are no longer being made and were very expensive. Looks like the 30mm socket will be the ticket. Thanks again.
/s/ CSV

[Jeroen]

good luck!