Lessons learned
I am in the process of cooling system upgrades. Radiator has now been cooked cleaned and flow tested. Had to make a trip out west and crew a boat at the last minute, so was very busy when I ordered parts, no time to stare at the fiches. Recommended was a screw type pump and fan clutch to match. These I ordered from AutohausAZ to 1989 E34 spec. as this is the engine I have been scavenging parts from. Parts arrived very quickly. Examination revealed a "SNAFU" and the nameless bastard would be me. E28 stuff is four bolt for the clutch. E34 is a three bolt pattern and will require an 11 blade fan specific. I will make an assumption that a 9 blade would fit if I had ordered for 1988 E28. Rats.
I looked at what others said regarding thermostats after examining the parts you see in the photos. The housing that I am using is an "A" My measure showed 8 mm gap. Cooked the new thermostat and the over all length grew to that number, so good to go. It also became obvious that my scrap motor had the wrong thermostat. Possibly what lead to its demise and ended up in the scrap dumpster.
Also, there was some talk about "over-clocking" the pulley, or smaller O.D. I have two pulleys that are 144 mm. One will fit the newer style pump and the other to the bolt on style. These will not interchange. Now I look for the 130 mm pulley that was post 9/89.
Any suggestions?
The "swiss cheese" thermostat is a bit of a hoot, lightened for full race! Might as well have run with no thermostat at all. This was in the car from the PO. I do not know what to say as to the water pump. Cheap aftermarket? Tough call as to which design will move more coolant.