I have notice a interesting casting difference between 2 different s4 pumps I have. The stock? one seems to have a shorter base with a long nose and the aftermarket ones seem to have a longer base with a shorter nose. the aftermarket units seem to have more water capacity in the pump area.
I thought all s4 units were the same.
any info on this?

 

where did u get ur aftermarket one ?

its called "aftermarket" for a reason.

 

no all the aftermarket ones are like that.

 

this is the stock style
http://cgi.ebay.com/ebaymotors/87-88...s#ht_500wt_975
and the aftermarket
http://cgi.ebay.com/ebaymotors/Mazda...0#ht_638wt_732

All the aftermarket pumps Ive found are like that^
Its a slight difference but it effects mounting of certain pulley kits. I want to know if anyone knows where you can get the stock style from a regular parts supplier. not mazda

 

Your examples don't allow for much of a comparison, so I can't tell what you're talking about.
At any rate, what pulley kits are affected and in what way?

 

awesome photos for comparison, you have solved the mystery for sure

 

Ill try to get better pics tonight my cameras on the fritz. Its suprisingly difficult to find a good picture of the stocker? online. It seems the gilmer kit is effected.

 

I noticed a HUGE difference in the quality of the impeller castings between the oem and aftermarket. I spent a lot of time cleaning up the replacement impeller with die grinder and dremel. If I hadn't already had the car apart on a weekend, I would NEVER have installed the aftermarket.


That being said, I think the waterpump on my car needs to go back to oem...thanks for the reminder.

 

I don't see how that's possible.
The basic geometry of the pulley set is determined by the main (e-shaft) pulley and everything else has to align with that.
Are you saying that the mounting flange of the aftermarket pump is so thick that the inner edge of the pulley hits it?

 

Basically yes. the factory pulley doesnt sit as deep on the housing. Ive tried 3 different after market pumps and the problem persists. the factory pump works fine though. I corrected the issue by having the pully boss pulled off the shaft by 3/16ths of an inch.

The aftermarket pump has ribs that dont sit flush with the flange so the pulley just barely rubs

 

I replaced my water pump about a year ago. if you call up Ray Crowe @ Malloy Mazda (forum vendor here) they will get you an OEM (remanufactured) pump for like $5 more than Autozone after the core is returned.