weight stamps, teflon and a frankenstein motor .....
 

Okay, to start off, the engine that I bought from a local guy from the boards to do my turbo swap ended up having no compression after I let the project sit for a few months. The motor supposedly had ~125psi on all faces when sold by Rotary Resurrection to said local guy. It was not built by Kevin, just ended up in his hands somehow. I figured that the lack of compression was just carbon lock. I was right... apex seals took me 30 min to remove and the side seals are still cemented in after washing the rotors twice already. This motor has definately been rebuild in its past.. the housings are immaculate and the tensioning bolts all have red-ish paint on them.

Now we get to the strange part. I had read somewhere that all turbo rotors, or at least most, have a teflon coating to help keep the heat down. Only one of these had that coating on it (feels like thin plastic lines going laterally down the rotor face). I then looked at the weight stamps. One was a "C" weight and the other was a "C" with an "E" over it, so it looks kind of like this: "€". Then I got to looking at the combustion chambers, I am officially stumped as to why someone would actually build a motor with these rotors.

One pic is to show off my housings... the other is to show you what I am dealing with here.

Also, this post is not complaining about Landers or RR... I know it is a good business.


What are these rotors from? They dont match at all. How long would this engine technically last with two completely different rotors?

rotor housing... immaculate? how? that thing is filled with chatter...

Nicest I have ever seen in person :dunno: No chipping, no dents, not even any spots worn much at all.

those housings look really nice - those rotors aren't even similar!

weight the rotors to see if they're the same, don't look like it and doesn't sound like it.

http://www.mazdatrix.com/r-rtrwgt.htm

might be the picture?
looks chattery, dont you think

does look that way, but I would not complain if it was mine, I'd be happy to see a housing with equal wear lol

afaik no rotors had a teflon coating ever, you may be confused with the ptfe coating all FC housings got to aid break-in (FD's switched to a graphite coating)

The rotors are definatly s4 or later as they lack the CNC marks. The frist rotor may just be a poor cast or something, as the combustion depressions are suppost to be symetrical and that one appears not to be. Weigh the rotors.

I weighed the rotors on a scale like you might find in a gym or doctors office. The one on the right was about 10.25, and the one on the left was about 10.50. I can try going to UPS tomorrow and using their digi scale.

Back to the teflon thing, I really dont know where I heard about it. I remember someone saying to be careful when cleaning turbo rotor faces as you can take off the coating... The one on the right definately isnt smooth metal, when you rub your fingernail across it you can hear it going over tiny ridges at regular intervals... you can feel them too.

my 87 TII rotors are that way, one baby butt smooth and the rough as a file

Look again for a "B", "C", or "D" stamp somewhere else.
I think you're looking at the Japanese katakana "YO", which looks like a backwards "E".


-Ted

on Turbo rotor and one NA rotor? as the turbo rotor would have a bigger dish because it is lower compression

just a guess

I've seen nearly new housings look like that. It's good.

Okay one rotor definately has a C with an E pressed over it, and on the other side there is a definate E. The other rotor has a C on one side and an E on the other.

Okay, my digi cam cant take very good close ups, so I did a rubbing of the marks on my rotors and scanned them. Sorry for the crappy MS Paint work I did.

The rotors in my NA looked just like that. One smooth, and one rough. After I got the rotor gears out, I placed one on top of the other so the sides were flat against each other. No matter how I shifted the two, aligning with my fingers, it felt like the rough one was ever so slightly smaller. Maybe a few thousandths.


I wonder if Mazda may have used rotors rough machined to much to go thruogh the finish machining operation? After all, they're so close.


The teflon coating on factory rotors is on the side. Between the side seal and the edge of the rotor face. Possibly only S5? I'm not sure.