Ok, So I decided to spec out one of my rotor housings tonight and found that at it's widest it is 80.02 mm and at it's thinnest it is 79.55 mm, Now I know mazda factory specs are to be within 0.06 mm. So my question is when I go to put my motor together will the sealant make up for the difference in material or should I find a new housing?

 

Forgor to clarify the steel liner is at 79.93 mm but the width of the aluminum casting is 79.55 mm

 

if the aluminum width is really that minimal then pitch it, it's a paperweight. i'll usually go as low as 79.85 and clearance the high spots but a housing much thinner than that may run into rotor to iron contact issues.

 

Ok, time to start looking around craigslist again I guess, which is fine since I need a good center Iron anyway, and the engine I took this rotor housing from I only paid $20 for so its not like it is a huge loss of investment. This rotor housing is from an S5 NA, would I be able to use an S4 rotor housing with my other S5 housing (assuming it is in spec) or are the spark plug locations different?

 

That's a pretty badly warped rotor housing, definitely not useable. Sounds like the donor engine was overheated badly.

 

No, I hate to admit it but I think I went a little too heavy with the whiz wheel

 

Womp womps.

 

The spark plug placement is different on the S4 and S5 housings.

 

yeah, you will have to keep the rotor housings within the same series if they are USDM parts. japenese versions all had the later model spark plug timing though, so a series 4 Jspec housing can be mixed with a series 5/6 housing. a USDM series 4 housing though cannot be mixed with any series 5/6 housing.