While the car was at the Robinsons, I put the motor on a stand and did a little motor preventive maintenance. I replaced the rod bearings with BE Bearings and OEM bolts, rebuilt the VANOS with the Beisan kit, replaced the front main seal, vibration damper, and water pump. I also capped off the water lines running to the cabin heater. While the oil pan was off, I had an NPT bung welded on for an oil temp sensor. I also installed Rogue Engineering undrive pulleys. In talking to Ben, he expressed concern that the undriven altenator may not provide enough charge at idle to run the car and with the 10 lb ETX14 battery I will be using. So I opted to use the stock altenator pulley and had to measure for an appropriate belt. A 1520mm belt fit perfectly. As it turns out, the Rogue alternator pulley doesn’t fit the Z4M alternator anyway. Well, it fits, but is out of alignment with the other pulleys. You would need to mill off 1-2mm to get this to work.
Was definitely time for new bearings.
With the transmission out, it made sense to use the ZF 5 speed I had in the shop. I also had the Bimmerworld strapless clutch kit from the S52 that will mate the S54 to the ZF tranny. The ZF is 20 lbs lighter than the Getrag 6 speed. Mounting the shorter ZF is pretty easy. Order yourself a transmission mount from a 2.5 Z4 that came with this transmission and it then bolts right up. The driveshaft did have to be lengthened 100mm by a local driveshaft shop. I also had to have a custom length DSSR fabricated for the gear selector.
I also took advantage of Turners Christmas deals last year and picked up a set of the Supersprint full stepped headers and section one. I had them ceramic coated to keep underhood temps down.
