ok, i tore down my always beleived to be virgin N/A engine (died of water seals) for the rotors to use in my turbo rebuild. but i am confused

one rotor's faces are polished smooth when cleaned up and the other rotor's has noticeable machining marks from when the rotor was milled?

i am about positive this engine was never rebuilt, it had 3pc. seals and wire coner seal springs, and no gasket maker anywhere,

what is the deal, i thought they were a matched set, or at least the same weight code, or can someone explain this to me?
thanks
zac

 

i thought the milled ones were S5, weigh them.

 

yeah they are S5's, i mean you can see the milling marksonly in the valley of the of the #1 rotor, but the second rotor you can feel them easily on the face as well,
whereas the faces on the first are completly smooth, cant see or fell any marks cept for the compression valley or whatever you want to call it

jsut wondering why this would be and if i should try to get two that are the same???
how do i determine the weight code also......there are a couple different letters on each of the rotors

thanks
zac

 

http://www.mazdatrix.com/faq/rotorwgt.htm thats for the weight.

 

Lines on the face are of no meaning or consequence. YOu routinely see this on 89-95 rotors, and I've even seen a few (late, I assume, near the changeover point) 88 rotors with these on the face but a cast compression dish.

Bottom line, you always go by the dish, and nothing else. Having lines on the face of one rotor and not the other means nothing, and it is completely possible that it was built that way at mazda. I have no way of knowing this for sure, but from what I do know and can imagine from a mass-produced assembly oriented environment, there are probably carts of rotors from pre-balanced (to some degree) like weight 'ranges" (the letters) and assemblers would simply pull 2 at random from the cart during the builds. Perhaps some of the production equipment made lines on the face while some did not.

 

thanks, that makes alot of sense......you are correct, the marks on the dishes of both rotors are the same

thanks though
zac