Advice for weekend warrior about to attempt first 12A rebuild.

[brycerxer]

I've had this 85 GS for several years now. When I got it, it had overheating issues. I came to believe the o-rings were shot. A couple years ago, I got a free 84 parts car that supposedly had a good engine. After swapping, it seems the front rotor has no compression. Now, instead of selling of all my rotary stuff, I've decided to take it to the next level and try a rebuild. Getting started on this rebuild, I've decided to also start a build thread. As I'm going into uncharted waters, I wanted both to document what I'm doing as well as get some feedback from those of you who've rebuilt 12A's before.

I'm looking to use this car for a semi-daily driver and it will need to pass emissions (AZ). I wouldn't mind getting some extra horses here and there- expecially if it's cheap - that's why I'm intrigued with the idea of porting (if it will pass emissions). Plus, I have two 12A's, so I could practice on the bad housings first. For the most part, I just want to restore to factory and have a reliable semi-daily driver.

Any advice would be much appreciated. I've gotten to this point with just the help of a Hane's manual and online forums, so if there are things that you feel every rotary rebuild should include, or any pitfalls to avoid, let me know.

[WE3RX7]

Sounds like a fun project.

Is it all of mericopa(?) county that has emissions or just the city of phoenix?

Either way, porting is difficult to have with still passing the sniffer, but it can be done. You should be able to perform a mild streetport and pass, especially if you maintain cats during the testing phase.

Some other areas to look into might be getting the rotors coated (turblown.net in AZ does it). If you decide to reuse the rotors from the over heated engine, I would invest in new rotor bearings. You can get away with a cheaper rebuild by just replacing the apex seals, springs and side seals, but for reliability - I'd replace the rotor bearings, oil seals, etc as well.

Be sure to check the step wear on those irons too, nothings worse then putting together a nice new rebuild with warped irons!

[brycerxer]

Originally Posted by WE3RX7

Sounds like a fun project.

Is it all of mericopa(?) county that has emissions or just the city of phoenix?

-Just in Maricopa County.

Either way, porting is difficult to have with still passing the sniffer, but it can be done. You should be able to perform a mild streetport and pass, especially if you maintain cats during the testing phase.

-Can you define "mild streetport" or point me in the direction of a template?

Some other areas to look into might be getting the rotors coated (turblown.net in AZ does it). If you decide to reuse the rotors from the over heated engine, I would invest in new rotor bearings. You can get away with a cheaper rebuild by just replacing the apex seals, springs and side seals, but for reliability - I'd replace the rotor bearings, oil seals, etc as well.

-What does this coating do?

Be sure to check the step wear on those irons too, nothings worse then putting together a nice new rebuild with warped irons!

-I will definitely avoid that. Thanks for all your input. Do you think the Hane's manual is sufficient or would you recommend I buy a rebuild video from Mazdatrix?

Thanks again.

[WE3RX7]

Haynes manual isnt that great for doing a good rebuild. I'd invest in the video if you can, or find a good Factory Service Manual download in PDF format.

[Teenwolf1393]

if you want a good video that can help got to atkinsrotary.com, they have a full line of DIY engine rebuild videos

[WE3RX7]

Also, check out Rob's videos online for free: http://www.rebuildingrotaryengines.com/

Its a good resource albeit not a complete set... he still has some good pointers.

[brycerxer]

Thanks for the info. I was looking at Atkins for a rebuild kit - the $249 one. I couldn't do an online credit card order (and I don't have PayPal), so I'll have to call to order. So maybe I'll order the video too. I'd really like to find one specific to 12A's, cause all I've seen are 13B videos. I will also check out Rob's videos for sure.

My understanding it that 12A housings and irons are unavailable. My plan at this point is to continue disassembling this first 12A (and storing in organized bins) until the engine stand is empty. Then I can pull the other 12A, mount it on the stand and disassemble it. Then, I can check for specs on all parts from both and use the better parts from the two. Do this sound like a plan?

Hey WE3RX7, I'm curious about your "mild streetport". Can you expand on this or point me toward a template?

Thanks again for all the input. I'll post more pics as progress is made.

[brycerxer]

Well, I got my rebuild kit from MazdaTrix today -just in time for a 3 day weekend. I didn't waste any time. I used the box that it came it to compartmentalize the rotor springs/seals, then began taking them out, cleaning them and carefully placing them in the appropriate place. Now that I have everything out of the rotor I'm finding it difficult to clean all the rotor's nooks and crannys.

What is a safe cleaning solution to spray on the rotor - that won't damage the aluminum? I remember someone saying they spray carb cleaner and blow it out with the air compressor. What about seafoam for the carbon buildup?

[brycerxer]

Here's a couple questions:
1) Do you think that this housing will hold oil. Look at pic #3 where it is cracked. I'm wondering if the oil pan and gasket will hold oil. Can it be welded back in place?
2) How do you clean out those water jackets?

[rotaryracer]

How did the rebuild turn out? I'm gathering all of my engine parts from my engine failures and will begin rebuilding what I can.