(COOLING) FC aluminum water pump housing on a FB
Thread Starter
Joined: Jul 2008
Posts: 1,671
Likes: 9
From: Chino Calif
Here you see an S4 WP main housing and a 79-85 GMB impeller. The gasket is an S4 and lines up perfectly on all but one hole; alt bracket hole location difference is clearly visible.
Differences in alt brackets themselves. Top is old school 3B/early R5 with external reg alt. Middle is typical FB with internal reg alt. Bottom is FC. Notice only the length increases for the FC as its bolt shifted lower in the WP.
gearhead-42 posted this nice pic of a new GMB.
Here is my OEM 3B/R5 heat shield stud with an oddball oversized 15mm nut I had lying around. A regular 14mm exhaust nut would also work perfect here.
Sorry I don't have any more pics of the WP fully assembled or installed. Maybe later.
Differences in alt brackets themselves. Top is old school 3B/early R5 with external reg alt. Middle is typical FB with internal reg alt. Bottom is FC. Notice only the length increases for the FC as its bolt shifted lower in the WP.
gearhead-42 posted this nice pic of a new GMB.
Here is my OEM 3B/R5 heat shield stud with an oddball oversized 15mm nut I had lying around. A regular 14mm exhaust nut would also work perfect here.
Sorry I don't have any more pics of the WP fully assembled or installed. Maybe later.
I will use that "special bolt" from the front iron and mount my standard FB alt bracket!!
For you guys that are thinking... "why is he fussing over only 14 pounds"!!!??? I have pulled out over 140 pounds in the last couple of months and still have many pounds to go!!!
On my lightweight autocross car, I REALLY felt those 140 pounds gone!!!
I plan on doing more mods and hopefully I will be soon down to 1900##
Congrats on finding the right stud! Yes it should be 10mm x 1.5 You can test it with an exhaust nut. Also take it with you when you get a tap to triple check that it's correct.
An FB gasket should work. Check how it will seal around the FC waterpump though.
An FB gasket should work. Check how it will seal around the FC waterpump though.
Joined: Mar 2001
Posts: 31,833
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From: https://www2.mazda.com/en/100th/
i was actually thinking about putting my alternator where the airpump used to be, it doesnt save any weight, but it does move the 14lbs from up high to the right side which is really light
1900? thats LIGHT...
This is the GMB impeller, the part that moves the water, it's stamped steel (not aluminum) and doesn't flow as well as the stock cast piece.
This photo was originally posted in this thread started by trochoid in 2004
https://www.rx7club.com/showthread.p...r+pump+housing
This photo was originally posted in this thread started by trochoid in 2004
https://www.rx7club.com/showthread.p...r+pump+housing
Yep, it's not quite as good, but if you're running NA, it's good enough.
I do remember that thread. I referenced it before I experimented on my GMB. By the way, what's the green stuff? Always wondered but never asked.
I do remember that thread. I referenced it before I experimented on my GMB. By the way, what's the green stuff? Always wondered but never asked.
This is the GMB impeller, the part that moves the water, it's stamped steel (not aluminum) and doesn't flow as well as the stock cast piece.
This photo was originally posted in this thread started by trochoid in 2004
https://www.rx7club.com/showthread.p...r+pump+housing
This photo was originally posted in this thread started by trochoid in 2004
https://www.rx7club.com/showthread.p...r+pump+housing
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Joined: Jun 2004
Posts: 11,359
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From: Grand Rapids Michigan
WHat do you think the weight difference between a cast iron and an aluminum pump??
I have not bought the pump yet, just modifying the housing. Guess I can do the mods and put an aluminum one on.
Kentetsu, do you just tap a hole in the FC housing for the 1st gen water pump??
Also, any other leads on how to get one of these GMB aluminum pumps??
I have not bought the pump yet, just modifying the housing. Guess I can do the mods and put an aluminum one on.
Kentetsu, do you just tap a hole in the FC housing for the 1st gen water pump??
Also, any other leads on how to get one of these GMB aluminum pumps??
I didn't drill/tap any holes when I mounted the the fb pump. Not all of the holes lined up, but with a bead of sealant to go along with the gasket it seemed to be more than enough to work...
Thread Starter
Joined: Jul 2008
Posts: 1,671
Likes: 9
From: Chino Calif
I think the iron pump weighed about 6 Lbs, but I'm not sure on that. The aluminum pump weighs about as much as a can of beer.
I didn't drill/tap any holes when I mounted the the fb pump. Not all of the holes lined up, but with a bead of sealant to go along with the gasket it seemed to be more than enough to work...
I didn't drill/tap any holes when I mounted the the fb pump. Not all of the holes lined up, but with a bead of sealant to go along with the gasket it seemed to be more than enough to work...
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Joined: Jun 2004
Posts: 11,359
Likes: 14
From: Grand Rapids Michigan
No, I didn't tap anything. I don't remember what hole I used, but it was an existing one. I'm sure I'll forget, but I'll try to grab some photos when I get home tonight (damn, just remembered I was supposed to measure the Bilsteins for Billy over a week ago too!). Guess I'd better get to work when I get home.
Joined: May 2002
Posts: 5,972
Likes: 37
From: Ottawa, Soviet Canuckistan
Lots of great info and pictures, looks like another thread for the archives!
And yet another thing to add to the checklist of stuff to do on my S3... damn that list gets long if you aren't constantly hacking away at it!
Jon
And yet another thing to add to the checklist of stuff to do on my S3... damn that list gets long if you aren't constantly hacking away at it!
Jon
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