Water pump rebuild m10 vs m20

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Joined: Sun Jul 13, 2014 5:55 pm
My E21(s): 1980 323 euro with Alpina upgrades
Location: New york and Vermont

Water pump rebuild m10 vs m20

Post by peebuck »

Hi yall

Im over here trying to find parts to rebuild my water pump on my m10. Basically doing a price comparison to see if just buying a new pump or rebuild is more economical. New pump as seen on Braman Motors web site is $255 us plus shipping. I Haven't yet found a rebuild kit for the M10 I have seen for the M20. On RimmerBros for $15.30. But as Jimmy tells us "all that glitters is not gold"

Im in the process of cross-referencing part numbers between the two engines. I see that the bearings are interchangeable and Im assuming that the seals will be compatible as well since the bearing passes through them. The issue I see is that the impeller doesnt seem to be compatible. As well I cant find a part number for the housing and the pump as a whole is not compatible m10 to m20.

Does anyone know the difference between the two impellers m20 #11511280827, M10 #11511268824 & #11510686110

My concern is that the impeller is thicker and potential has more fins and that the housing is deeper to accommodate. I imagine that the m20 will need to move more water as it is a lager engine. Happy motoring and wrenching :driving

[img]C:\Users\Stew Pendus\Pictures\Screenshots\Screenshot 2022-12-24 111025.jpg[/img]
(im trying to incent a pic of the parts diagram doesn't seem to be working)

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My E21(s): '81 323i Baur
Location: The Netherlands

Re: Water pump rebuild m10 vs m20

Post by Jeroen »

Yup, don't think many parts are interchangeable. I'd consider ordering a water pump from Germany based Autodoc, examples:

(I used a QH water pump on my E30 race car and it lasted for 5 seasons, then I sold the car)

slightly more renowned:
Regards/groeten, Jeroen
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