Water pump pulley spacer/shim

[BadDog]

My '73's original radiator sprung a leak, so I am replacing it with an MSA aluminum 3-core unit and am taking the opportunity to replace almost everything else in the cooling system (water pump, fan clutch, thermostat, hoses). Before I removed the fan and water pump, I test-fit the new radiator. Not much clearance: I could barely get my index finger between the center of the fan and the new rad. The blades themselves had a little more room though. I called MSA about the narrow clearance, and they wondered if there was a spacer there from dealer-installed AC (the AC system was removed by the PO many years ago). I saw nothing that I would describe as a spacer until I removed the water pump pulley. There was a narrow aluminum spacer/shim inside the puller cover. I haven't measured it yet, but I'd say it wasn't much more than 1/8" thick.

Is that spacer leftover from the original A/C, or is it always supposed to be there?

[240260280z]

Info in cooling system here may help: http://datsunzgarage.com/rebuild/index.htm

This got my attention: "the reason is that 3-row fan hubs were made longer to clear the long balancer."

Not sure if you still have stock motor and parts or if you put L28 in your 73... but maybe you have same issue

[5thhorsemann]

Bad dog, This is the fan/rad clearence on mine (73 z), it has a 280 rad, but the fan and WP are stock, I'd call it like 1,5 to 2 inches. The 1/8" spacer is there to align the pullies if it was under the pully. I think you are dealing with an aftermarket fan, or a really thick fan spacer.

[BadDog]

Thanks guys. I got a hold of my local Z guru. He'd never seen one of those spacers before, and figures it was due to the A/C that is long gone. I checked the pulley alignment with and without it, and the pulleys line up better without it. Also, all pictures that I can find of that pulley all show it closer to the block than mine was. I decided to go without it since the alignment looks better and the extra 1/4" of space really helps my clearance problem.

Edited April 3, 2011 by BadDog

[ajmcforester]

Make sure you only have two belt grooves on the balancer, otherwise the fan will hit the third pulley without the spacer

[BadDog]

I have 3. I got lucky, it clears by about 1/8th inch. Guess I'll look into a 1-groove crank pulley!

[beermanpete]

On my 73 240 the front crank pulley groove (of three) is bolted to the damper. It is used to drive the somg pump. If your car has this style of damper and it is not in use you should be able to remove it to increase the clearence with the fan.

[BadDog]

...and shave some rotational mass to boot! Thanks!