Anyone know if I can use non-turbo rotor housings for my 87 Turbo motor rebuild? https://www.nopistons.com/forums/pub...1047683561.gif

If so what mods would be necessary?

I know the inserts for the exhaust ports are sometimes different (which would normally be pulled for porting anyway), but not sure about the spark plug holes, port timing of anything else.

Anyone familiar?

I'm pretty sure that you cant mix NA housing with turbo rotors , because the compression is different. the only way you could use NA housings is if you got some NA rotors, But then your compression would be much higher. In turn would give you more HP, but also give you more chance to detonate.



The 86-88 NA models had compression ratio of 9.4:1 VS. the turbo model 8.5:1

I appreciate the feedback RE TurboFB, but I'm pretty sure that not true, (about the rotor housins effecting the compression). It has been a little while since I played around with this idea, so I can't say exactly what it was that would not allow a direct swap, but I'm pretty sure it wasn't because of compression. The rotors themselves are what effects compression. They determine this by the size and depth of there pocket chambers. I don't think the housings would change this. It must be something else. I'll have to check into more. Thanks though.

The plugs are in different place. Use s4 s5 s6 turbo rotor housings no problem.

That's more or less what I remembered. Thanks Nos

ok so wow i have no idea what the hell happened to that guy the compression is determined by the bevel in the rotor the housing makes no diff. The only thing that is diff is the insert in the exhaust port. The turbo does not have the fins and is bigger. So it will get better flow to spoll the turbo. The fins in the na one are put there by mazda to cut down on noice pollution. So here is what you do drill the pins on the side of the housing that holds the insert in. Pull the insert out and then lathe the fins and **** out so you have a little metal cherrio when you done. put it back in and weld a pin on each side where you drilled it out and now your na port is now bigger than turbo. but either way the housings will both work even if you don't mod the na one. it will just give you a less responsive turbin. good luck