I picked up a D series 20B 2 weeks ago and i started taking it apart last week and i saw that it has 2 thermostats its cool and weired but why is that? Can i find a neck that just holds one thermostat? also my 20b does not have a fill neck were you open to add coolant. were can i find one like that? iv seen alot of 20b's on the forum were the thermostat housing theres a radiator cap were you can fill coolant inside. PLEASE I NEED INFO!!!!! do people use an FC or FD front housing to have that fill neck coolant? or what??????? Sorry if i sound retarded im new to 20B's

 

I had to learn it all too. I swapped to an FB (1st gen RX-7) front cover and easily fit an S4 FC waterpump. I recall I had to move one of the waterpump studs in the front iron to a threaded hole next to it. Mazda was extremely awesome for making their newer (at the time) engines backwards compatible with earlier parts.

Did you break any exhaust studs yet? The turbo unit weighs like 62 pounds or something. All the heat cycles cause usually at least one stud to snap when you go to remove the manifold from the engine.

 

the studs look brand new all the bolts on everything looked brand new when i took it off even the twins look to be very low miles im really surprised this motor looks to be very i mean very low mileage