Water pump internals

Yes! Rather! Maybe you can convert from the late two-piece-seal to the one and only reliable one-piece-seal.

Can you show another picture with the back of the impeller?
The "washer" between circlip and and inner bearing actually is a leaf spring washer. The spacer between inner and outer bearing is a simple part everyone with a lathe can make in ten minutes.(ID 15mm, OD 20mm, L=36mm

Best
Martin

 

It's unnecessary, because with the big bearings pumps the seal was the problem, not the bearings. And a leaking seal with a clogged weep hole destroys the bearings. No matter how many.
But when someone insists on a third bearing, what makes the whole situation statically overdetermined btw, you even need two spacers, 11.5mm long each. See my CAD screenshot. Without spacers it is a complete hack job and I wonder, how the pulley can be fastened tightly. Without spacer(s) between the inner bearing races you would simply push in the outer bearing while tightening the pulley nut. In the end the pulley would collide with the housing. Sorry, but someone in the past was completely unaware about what he was doing with your pump.

See also my last posts of this thread on page 4 for what you need for a rebuild.

https://www.ferrarichat.com/forum/threads/water-pump-rebuild.362611/page-4

Three bearings draft with inner race spacers:

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or like this. But then i would rather look, whether there's a two-row bearing in the needed ID and OD and adjust the spacer's length accordingly:

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Best from Germany
Martin

 

Hi Jay,
you are correct. This design needs a different impeller. It's the perfectly original, earliest big bearing design with the earliest two piece seal (and the least reliable). Did I already mention my thread from 2011, when I have shown my design modifications from old two piece seal to modern one-piece seal?

https://www.ferrarichat.com/forum/threads/another-waterpump-conversion-thread-old-seal-modern-seal.514339/

Don't know why, but the embedded link to my oldest thread from 2011 is broken. So here's the direct route:

https://www.ferrarichat.com/forum/threads/308-w-pump-altering-design-old-to-new.328021/#post-140610396

First of all; don't worry about the spacer between the two bearings. This impeller/seal design changes don't affect the bearing design. The spacer of all "big bearing pumps" is identical in length and inner/outer diameter.

These are the two impeller versions:
Earliest two-piece seal design with the thicker seal portion (19mm? out of memory) on the shaft: Like for the one you show above:

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Later design for the later two-piece seals and the latest one-piece seal (seal portion on the shaft out of memory 16mm(?)
Like your original pump:

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The pump you purchased is the perfect version for the conversion I describe in my old thread from 2011. Since you have to cut down the diameter on the shaft for the seal from 19mm to 16mm anyway (dimensions out of memory, you should compare both shafts for confirmation), the condition of the shaft doesn't matter at all.

Best from Germany
Martin

 

Hello together,
while digging in my collection of official Ferrari Service Bulletins I also stumbled across one for the introduction of the first waterpump modification with the improved two part seal. I have attached it and one can see, it was an act of desperation fitting a rubber seal behind the inner bearing and working with Loctite on the impeller/shaft.
Only the next modification with the one piece seal made the pumps finally reliable.
But what's visible on the Bulletin is the comparison between the shafts. The difference in diameter of the seal portion is not 19 vs. 16 like I wrote above from memory, but 18 vs. 16mm. Still enough "flesh" to cut down an old worn or rusted shaft to a perfect new surface.
And also visible are the different impellers. Fun fact; with the latest one-piece-seal modification it would have been possible to use the early impeller again.

Best Regards
Martin

 

Ferrrari Parts Exchange sold me a new 328 pump for $250 and I did not have to rebuild the old one

 

sorry, but

Sorry, but the "new" pumps are garbage. The seal and the bearings are cheapest chinese junk. As far as I found out, that whole thing is Made in India.

Best
Martin