i just pulled apart the 12 that died on me. found 2 sideseals stuck in,Spun Bearing,Center iron has bad burns and groves and the rotor side had deep scratches. (see pictures) the center iron is not just discolored,it is groved where the blue is .. HOW ? and this maybe a normal but i have never seen a 12 housing with that hole under the exhaust port (see pic) i have 6 sets and none are like that.

 

I'm no expert, and I have no idea really, but just looking at the pics it seems something maybe broke off and got wedged between the housing and rotor...?

 

Classic oil starvation. The rotor housing is from an engine that had a thermal reactor originally.

 

thats big time lack of oil. that sucker got HOT!

 

ok thats whats weird . oil was full and clean. i have a electric fan set up and it never got hot . as for something braking off and getting in there maybe but the sideseals,pacmans and plugs are all accounted for . good info on the housing .

 

I agree with the lack of oil thing. Just because the oil was in the pan, doesn't mean it was getting where it was needed. Could be something like a clogged passageway or a failed oil pump. Check that stuff out closely. I would also check the oil cooler, oil cooler lines, and oil cooler t-stat.

Also check the pickup tube (clogged screen, pinhole in side of tube, or poor sealing of gasket). On those last two items, it would be like using a straw that has a hole in it (doesn't work too well).

Check/clean anything oil related on that engine before putting it back together. You don't want to kill another engine by reusing a bad part.

 

Possibly a plugged oil passage inside the e-shaft or the passage from the rear bearing that feeds it... since the rotor bearings and side oil seals get their oil feed from there. A plugged e-shaft feed would let one rotor or both rotors run dry, depending on where it was plugged.

Did the other rotor look the same?

Yep, front rotor housing from a pre-cat smog motor, probably a Cali-spec SA.

 

another piece could be oil starved from previous, just because it is full now doesn't mean it always was, the original damage could have come from a long time back. A spun bearing can cause all kinds of problems including a large side load on the rotor which will cause side plate grooving

 

pics of the other side of the rotor would tell this, but its possible the rotor gear came out too

 

Remember too that the e-shaft also has jets that squirt oil into the cast hollowed recesses in the rotor - lots of small passages to check for bad oiling.

 

the housings are from the 12a that mazda put into my 79 in 1998(date on motor)when the original went.

the front rotor and the other side of the rear rotor are in perfect shape. even both housings are perfect. i will check into the e-shaft passages.