Still learning the ropes on what to look for. I think it may be fine but just to double check... Are these dimples and mark ok on the rotor face?? Thanks!

 

i think one mark is a Kanji stamping. for the others, i'll ask this: was the rotor wrapped in something for an extended period of time - something that could have trapped moisture?

at any rate, I would use it. i'm sure others have used worse. the only pause I might have would be a higher performance turbo application where every little detonation-fighting tip helps. the little imperfections may help carbon "stick" better and thus may be potential hotspots. maybe it's my relative inexperience with Turbo rotaries and i'm making a mountain out of a mole hill though. for an N/A application, I wouldn't worry so much.

 

try buffing it out first,clean it up more and then post another pic..but from what I can see it is fine.

 

I will have to wait until this weekend when I'm back at the garage. And yes diabolical, I had put marine anti-rust protectant on the rotor and wrapped it in plastic wrap for transportation back to my house. So besides those spots I mentioned, all the other imperfections is just from the plastic wrap.

I thought it was a Kanji mark too but this is the first time I have eld a rotor in my hands (and I'm treating it like my first-born lol). And this is a turbo rotor as well, going back into a turbo engine. I was just concerned about those dots because they were near the apex seal.

 

Not a professional builder, but if those are just 'marks' or imperfections in the surface of the face, I wouldn't worry. Now the ones near that apex groove might be something else. Do the marks intrude into the groove at all? What are the measurements of that groove? IIRC, the FSM sets out specs on them.

 

if the apex seals grooves are fine (with in spec) use them...

 

Upon closer inspection, I think that could be Kanji, I thought I found another one which looks like the number 5, just worn away mostly and definitely not as thick. Now the dots only, Ever-So-Slightly go into the grove, it isn't even noticeable, so I'd assume its good?

There are a couple more places with small clusters of 'dots' and a couple around the side against the housing walls, but generally this all looks good.

And last question, when cleaning the rotors I used a very fine sandpaper, almost as fine as an emory cloth and rubbed up and down with the grooves by hand. Is it ok to use a rougher paper and go in swirls or go with the grain? Trying to get every last bit of carbon off these things.

 

I sued sand paper ( 300 wet/dry) and some degreaser from auto part then use the square corner of an apex seal to make sure is clean at the inside the edges.. do not use hard metal brush.. you could damage the sharp edge of the grove..

 

Is it ok to clean in swirls? Or should I go up and down the grooves from apex to combustion? If I can brush in swirls and not worry about the grooves I will use an electric tool to polish it better. Just not sure if there is anything I may do to throw things off!

I am no mechanic, I can do board level circuitry repair so I am learning how everything works rather quickly, I am just trying to be SUPER careful with ERRYTING.

 

you can go up and down through the apex groove, just be careful on the side seals groove no to use that metal brush, the rest of the rotor you should be good with the wire brush. keep it up the attention to detail on cleaning..

 

not swirls, up and down following the lines is better

 

I don't see any Kanji at all

 

... and it may be because it's not. i don't know. i said "i think" because i wasn't sure. i said i think it's Kanji because i have seen rotors with similar marks (to the first photo) on the face. in my experiences, it hasn't been a common thing, but i have seen more than one over the years - probably because i spend a lot of time cleaning and polishing rotors.

the marks in the second photo I've seen on rotors that had previously rusted and then were cleaned up.

i wet sand rotors and i use 220s and 400s mostly. i change directions as much as i can before my hands start cramping, but i end up running up and down the face.

 

Still waiting for when I can get out to the garage, but yeah, I'm ONLY going to go up and down the face in alignment with the grooves. This is my first build and I don't want to compromise any bit of the rotor face, even if its over the top unnecessary. It's just really damn hard to clean in the corners of the combustion chamber, thats where most of the carbon still remains.

Do have another question though.. On the sides of the rotor I noticed there is an gold/olive hue to it. And on one side I started wiping in circles with a fine emory cloth and noticed some of it was rubbing away. Is it ok to continue wiping this 'film' away or should I leave it alone since its on the side of the rotor and doesnt have any carbon build up. As stated before, new to all of this so I don't know if this is a stupid question or not, LOL. Thanks!!