So I am getting my engine built by Lucky7 soon. Its a Series 5 NA and I am going to street port it. My question is what waterpump should I use? and what thermostat should I use. I have been told to go with the OEM Mazda thermostat from the dealer. What about the water pump does it matter? I will be running a Koyo radiator if that helps in guiding me

 

The thermostats my local Mazda dealer carries no longer have a "jiggle pin" and look to just be the same Stant part you'd get at Pep Boys.
I got my last one at NAPA.
A note about NAPA: If you ask for a S5 thermostat, their computer will spit out the totally wrong part #. Ask for a FD thermostat and you get the right one. Be aware that the sealing gasket is a separate piece and must be ordered as well, or you won't get one.

I got my waterpump from Mazdatrix- presumably an OEM part- since I only wanted to replace it once and didn't see the point in saving a few bucks and taking a chance.

 

The thermostat I got from the dealer had the jiggle pin and wasn't Stant but Motorad. Dunno if it is any good but seems to work fine so far.

 

so Mazdatrix for waterpump and where for the thermostat?
What do you mean about the "jiggle pin" what is that?

 

ITs like a tiny whinny grenade pin looking thing hanging on the Thermostat.

btw, I got a whole brand new Mazda Water pump from Mazda, includes everything like thermostat and stuff. price is ok.

 

yeah I called Mazda and they said $20.00 + tax

 

I've been going to the dealer. they've been beating all mazdatrix prices and it's only a $1 extra to overnight.

go to autozone and get a $90 lifetime warranty pump. they are good and come with both pump and housing gasket. never had a problem with one unless I had to ceramic coat a broken water seal.

 

I got a Beck Arnley from Black Dragon Auto with the jiggle pin.