Hello I bought two brand new rotors today and when ever I search the part number all I get are Russian sites but don't list what exact motor they are for! The part number is N3Y3-11-B10A. I'm starting to think they are RE rotors as the rx8, fd, and fc part numbers are all different from this one. Thanks!

 

I'm guessing one of the numbers didn't stamp nicely, specifically the N3** part.

Take a pic for ***** and giggles for us if you like. Is the rotor valley cast or machined?

Here:

https://www.mazdatrix.com/b3.htm

 

I'm interested in this as well. I've just taken my first engine apart and it's a rebuilt engine. Not sure what the builder used, so I want to verify for myself.

Will the valley on one type be smooth vs the valley on another type be rough/textured? I'm assuming cast = rough and machined = smooth? I may be completely wrong...who knows!

 

Exactly.
S4=cast=rough - think of a sand casting
S5=machined=smooth.

 

I bought them out of Japan, there brand new so I have a pic of the Mazda sticker with part number so its the right one. From the pics you cant really tell if its smooth or not but it doesent quite look like the s4 rotor I have.

 

Here are the pictures of the rotors.

 

looks like S4 turbo to me, i haven't seen cosmo rotors in person though.

 

How much does it weigh?

 

There not here yet, not sure on the weight.

 

my Ukrainian parts catalog is down right now, because they have been invaded, but i did happen to notice that in the USA the S4 turbo rotors are an N3Y2-10-B10A, and are all magically a C weight, but in the JDM parts catalog they listed the B and D weight rotors as well, and the part numbers were N3Y1 and N3Y3....

 

https://www.mazdatrix.com/faq/rotorwgt.htm

 

Ahhh interesting, I guess its pointing towards them being s4 turbo rotors which is not so bad. I'm guessing that part number just shows up in the JDM catalog and not any of the European countries that you can check?

 

the part shows up in the JDM catalog as a JDM part. not sure about europe their catalog doesn't go back that far

 

If you weigh the rotors we will know if the rotor is an s4. Also take a close up picture of the tub. We need to know if its machined or cast.

 

just post the letter code on it, should be a D

 

It looked like cast to me, but hard to really see