I finally got the rear iron off.
And this is what I found.

I have not found the top of the apex seal.
Second image shows damage at the top edge rotor housing. There is corresponding damage at the bottom. The rest of the surface is very smooth, no scratch marks.

Opinions: Is it worth continuing the rebuild????

 

First thought on this is that a 12a dead is impossible, 2nd thought is that I can't see any pics. Idk how you tried to attach them but photobucket might be your best friend here.

Edit: Scrap that. I reload the page after posting and there they are. As for the pics as I can now see them I can't see the seal there either. Have you looked in with a flash light to see if even half the seal is left or anything? As for the damage on the housing I'm not quite sure what you're seeing as damage. Is there a groove that seems to run along the entire face of the housing in 1 clean line all around? Or perhaps what I'm seeing as a groove might be a wonky wear mark.

 

I see a broken dowel pin on first pic?
Or is it me eyes playing tricks on me.

 

That sure is a broken dowel pin

 

I'm more worried about the broken dowel pin too. That looks scary. What did you do?

As for the "damage" on the rotor housings, that is just normal worn chrome. With the lack of 12A housings these days, you might consider reusing them with some new atkins apex seals. Atkins break-in well on used housings like that.

Take the engine fully apart. Show us some pictures of actual damage caused by broken apex seals, if there is any, and we can tell you what to do next.

 

Yeah, Jeff's right. Those housings don't appear too bad from the limited angle we have to go on.

 

Dowel pin aside, from what I can tell the housing pictured doesnt look bad or uncommon compared to a lot of the ones I see.

 

I took a pair of 12a housings from my spare engine to a guy here in Miami,and he returned them like this. They where in pretty bad shape, when I gave to him. He usually charges around $60/pair.


windows screen capture

Here you could see the chrome flaking in the bottom corner.


free image host

 

Thanks. Responses are encouraging.

Yes the dowel pin is broken. The other end is stuck in the rear iron.
Procedure:
1. Removed the 18 bolts.
2. Pried up slightly on the spot indicated in the Mazadtrix video, to achieve a slight gap.
3. Used a rubber hammer from that point on until I could lift it up. Doing so brought up the rear rotor housing as well.
4. Pushed the rear rotor housing back down and removed the rear iron. And that's what I saw.

So, I take it a broken dowel pin is not to be expected. Really NOT what I wanted to see at midnight last night.

The water jacket seals were still in the rear rotor housing without any breaks. (I broke the inner red one.)

The side surfaces are really smooth with no visible scratches.
There is discoloration on the eccentric shaft (visible flat surface).

I'll attach more pics when I get further in.

 

Here is what I saw last night, but now cleaned up a little and better lighting.



$60 for the pair sounds fantastic, even with shipping both ways.
I'll keep this in mind.

Thanks everyone.

 

Those housings are way past their use by date .

 

Im at here at the track talking to a few rotary engine builders and they all said both of your housings are paper weights.

vid from tonight.

http://youtu.be/wFUVVyZbCUA

It just took out a prostock v8. Ill post the vid later.

 

I wouldn't use housings that far worn, but if they were the last ones on the planet, I'd use them.

 

Thanks for the responses.
This is what I thought on Friday.
Not what I wanted confirmed, but what I needed to know.

Now what?

Atkins and Mazdatrix have advertised rebuilt 12a's, $4k, $3.5k.
Atkins has 12a housings made from 13b's cut down for $750, but I would still need all the seals and I'm not sure of the condition of the rotors as they are carbon-black on all sides.

I'm not quite ready to throw everything inside, push it out into the street and put "FREE" sign on it.

The body is good. Only visible rust is on the inside of the doors at the bottom, and its minor. 156k miles. Everything works except the hi-beam headlight switch, the rear window wiper and washer. New tires, 10k on the clutch. Repainted to original color (for my dad) 3 years ago.

If anyone has a suggestion, I will not hold you to it if it does not work out in the end.

 

2 engines for sale in the 1st gen classifieds.

 

Thanks. I'll check.

I need to think about this.

What I have (had) was an Atkins rebuilt with about 30K on it. I had expected it to last longer. The broken dowel pin is still a mystery. The short broken end was firmly stuck in the rear iron, but the large part going through the rear housing lifted out with little resistance.

The front housing has minimal flaking compared to the rear.
There are scratches on the side plates which do show in sunlight.

 

Those scratches would be from Atkins' block sanding - a practice I disagree with.

 

Don't give up, it sounds like you've got a nice specimen in about the same condition as my own car. Get a used, running, engine and swap it in. Then if you want a project, start hunting for good used housings and do a rebuild on your 'spare' engine. There's really no cause to drop $4k on a rebuilt 12A just yet. If you were even thinking about spending that kind of money, you'd be way better off to get a 13B with a GSL-SE front cover.

 

I like your thinking.
The initial shock has worn off.

My original time frame to have this completed was around July. The engine disassembly was far easier than I expected.

I'm going to clean the rotors to see what shape there in.

The broken dowel pin has me concerned as to what corollary damage. I see what appears to be heat discoloration on bottom of the side plates and flat surfaces of the eccentric shaft.

 

I've torn down 12As that looked way worse than those that were running just fine, thank you.

Nice thing about the rotary design, it's not particular. If you just put some functioning stuff in there it will spin and give you lots of kick for your buck.

That broken dowel pin is mysterious, however.

How'd you do that?

 

84 GSL 12a, all stock except the radio and speakers.

OK, not dead. Only injured.

Main issue: Clouds of white smoke from the exhaust, running rough, oil leaking.

Images:
Front rotor
Rear rotor
Discoloration on eccentric shaft
Discoloration on bottom portion of side plate front iron, looks like a smile (matching areas are visible in same location on other 3 side plates)
The little pile of black stuff is the largest pieces of what was left of the intake manifold gasket.

So far the apex and side seals seem to be in good shape, just gunked up.

I'm new at this and so far I assume all new oil seals are necessary.

Suggestion and thoughts most welcomed.

 

I have no idea how it broke.
I was not forcing the disassembly to the point of being over cautious.
I pried up the real iron to maybe 1/8" gap, then used a rubber mallet the rest of the way. The long part of the dowel pin could be pulled out by hand with nearly no effort. the short end was stuck firmly in the rear iron.

 

Oil seals look fine. They will need new o-rings, of course. I'd also do a set of competition outer springs too, but that's just me.

The discoloration on the shaft is a normal part of the hardening process Mazda used.

The smiling section you asked about is normal. Just degrease and scrape off the hardened bits of old coolant seal around the edges (razor blade from a box cutter works well). Don't lap or block sand or sand blast the irons or have them resurfaced. If you do, I'll come to your house.

Edit: Oh I see what you were talking about regarding the shaft. That is slight staining from the oil that a previous owner didn't change very often. Otherwise looks fine. The rotor bearings look fine as well from what I can see in the pic. That is the puzzle lock you're seeing there. Totally normal.

 

Extremely helpful and very encouraging.
Thank you.
While I'm looking for rotor housing I'll continue with the cleaning of the the rest.

 

Update.

Worked on the rotors tonight.
The apex seals, corner seals, side seals, all had movement, none were stuck.

Removed all the moving parts and nothing was broken.
Inner and outer oil control rings all appear OK, but I would not say the same for the O-rings.

Lots of carbon to remove, but no signs of damage to the rotors at this point.