Water pumps

[Darrel Kline <darrelk@domain.elided>]

Joel Brodsky wrote:

 >Very dangerous to mess with the locating pin, or the spacer. 
>If the spacer is not dead on flat with the pump face, the fan blade
>will be out of balance, and you'll need another pump very soon.

Joel, 
You make a very good point. This was definitely a concern and the reason I
tried to find a spacer that would fit before I took the grinder to the
waterpump locating pin and the spacer. The spacer is flush against the
waterpump hub face, and I didn't have to remove much material from the
spacer hole so I think it will be ok. Time will tell.

 >The most damaging event for a water pump, is a sudden 
>acceleration or deceleration of the engine, this causes a transmission of
>force from the belt to the water pump impeller and shortens the life.

  IH engines aren't exactly the quickest revving engines. So as long as we
aren't hitting WOT with the transmission in neutral we shouldn't have a
problem. What do you think? 

>I'm not sure if you can find a clutch fan that will bolt on the IH rigid
pump 
>that will not put the fan blades into the rad.

  That's not good news. The Napa waterpump I bought has two different bolt
patterns so there should be more choices for a clutch fan. My spacer is
only one inch thick, but the fan is a long ways from the radiator. Most of
the fan clutchs I've seen mount the fan on the engine side of the clutch,
which will help with clearance. There's no way I would spend $215 for a IH
clutch fan even if it would fit. 

 >There would be no noticable inprovement in fuel economy with a clutched fan
>than a rigid one. The engine temps are not appreciable unless you are
changing 
>the temp greatly during the day.  What kind of outside temp change is it?
20 at
>night to 100 during the day?  Usually you can change the thermostat
cheaper than
>a clutch.

  I'm not sure what you mean by this. I thought the very reason for a
clutch fan was better mileage. What I'm thinking is that when you're on the
highway going 65 mph (100 mph for Tom M. in Montana - reasonable speed law)
you don't need anymore air going through the radiator. The engine is
turning 2500 rpm and the fan is just drag. The clutch fan will disengage
with the engine below a certain temperature, regardless of the outside
temperature.

Darrel Kline
Colorado Springs, CO
1980 Scout II