Pulled apart some motors this weekend, and found these rotors. s4 TII type -e , came out of my old 10th ae motor..

Im staring at these things and wondering Why the hell they are grainy? The housings were fine, no damage or streaks from the rotors, and its on both rotors.

Did they come factory like this?

I cant see how both rotors would be damaged, and not the housings, with how the whole rotor is this way?

 

I pulled apart a s5 NA engine and one was smooth and the other was just like your rotors, all grainy.
I think it's normal or part of the machining process???? Idk

 

Thats just how the material looks from the factory. Looks like that edge pinched something at some point though.

 

Yea s5 rotors are machined like that, ive seen some variance in a set that were in the same engine, i think they machined them and then balanced them and made the sets, vence the slight difference in some sets

 

its just a machining mark, they needed to change the bit....

 

Yea im just tripped out by it , It came out of a 10th anni, i dont believe it was ever torn apart

 

finishing marks. some rotors are super smooth due to age and use. if you pulled some out of a rebuild they could have hundreds of thousands of miles on them.

 

it is a finishing mark, even when you buy new rotors some come out of the box smooth and some come out like that, its like they have one machine that needed a bit...

 

strange though, weren't S5 machined and S4 cast? Or was that just the combustion "tub"?