I am swapping the engine out of my '91 parts car into my '87 (both NA). I am going to swap the front covers and neccesary sensors, etc, but was wondering if my s4 water pump will work on the s5 engine. The reason I ask is because the car was in a wreck, and it screwed up the fan and bent one of the water pump pully studs. Because of this, I'm not even sure if I can even get the fan off without grinding off the studs, and then I would have to get new studs/pulley, etc, and it would just be a major PITA.

 

https://www.rx7club.com/showthread.p...ght=water+pump

Come on Sideways7, you know how to search by now.

 

Thanks for the link, but its not quite what I wanted. I actually did search, but nothing had what I was looking for. I already know they are different part numbers, but I just need to know if it will work. The closest I found was that to mount the s5 water pump on the s4 block, you had to grind something to make it fit. This makes me think that it will work, but I just wanted to make sure.

 

Come on, I know someone has to know this.
I just need to know if the s4 pump will fit on an s5 engine, its very simple.

 

water pump housing? or water pump?

You need an s4 water pump housing in order to use an s4 water pump. It's the same with s5's also. The water pumps from the s4 and s5 are different in that they bolt up different from eachother. I know this because I bought an s4 waterpump for my engine, and it turned out it didn't match the bolt holes on my s5 WP housing.

 

Damn. Thats what I wanted to know. I was planning swapping the whole housing and everything over. I guess I will just have to figure out how to make it work. Maybe I can swap the s4 pump into the s5 housings, if its not screwed up.

 

No, you cannot swap water pumps.
The water pumps have different bolt patterns.
It's actually on stupid bolt that's off, but it's enough to not allow the water pump to seal properly to the water pump housing.

I dunno what you're trying to do, but used water pumps are a crap shot.
Most likely the internal seal goes bad, and it'll leak like a bitch through the weep hole once you install it.
For some reason, if the water pump (seal) doesn't see constant coolant, the seal tends to dry up.


-Ted

 

Thanks for the info, ted. What happened is that I am swapping in a 91 engine from my parts car to my main car (an 87 - yes I know how to do the swap) to get it running. The parts car was in a wreck and it messed up the fan and bend a few of the studs that hold it on. There is a possibility that the actual water pump is messed up as well. I have a water pump from my 87 that I was wanting to swap on since I know its good.
I guess I can't do it, though, so I'm SOL. I'm sure I can figure something out.

 

Ok, looks like there was some confusion on both sides. I just looked on mazdatrix and the waterpump front plate gasket is the same for all FC's, so the s4 pump should work. There might be a bit of grinding, but I can deal with that.
I forgot to mention that another reason for using the s4 pump is that I sold the s5 filler neck thinking I wouldn't need it, and I don't want to have to locate another one.