My First Rebuild Thread '79 12A
 

Well it all starts today fellas. I'm gonna attemp to overhaul the 12A in my newly purchased 79. I got a good couple months of fun in before the inevitable had to happen. I got my Haynes and Chilton manuals, as well as the atkins rotary dvd, youtube, and of course this wonderful rx7club site. Step one was a complete success; cracking a keystone light. I will probably be posting a lot of question in here as well as giving updates on how things are going. Time for step 2; tagging everything and pulling out the digital camera. Wish me luck!

Go for it!
Just re-assembled mine (80) using the MAZDATRIX video which is excellent. have the Atkins DVD too and it has some good tips. I got new info out of BOTH so its another $29 well spent for a "2nd Opinion" and more tips...
;)

Big moment will come when you split the housings and see what shape the rotor housings are in...

'luck
Stu Aull
80GS
Alaska

if you find you need housings or rotors pm me I have a few good parts left

Thanks Stu. I think I will pick up the Mazdatrix vid as well. I got a little sidetracked last weekend but the engine is pretty much ready to come out. It is seperated from the tranny but I still have a couple connections to get to. I found that the FSM was more helpful than the Chilton or Haynes manuals. It's more detailed. The pictures were a little easier to understand as well the numbers pointing to things on the pics. I'm excited to see what the inside looks like. Motor has 155,000 so it could be interesting, although I don't know the history of it. Will keep you posted.

Thanks. I am hoping to get everything opened up by the weekend. I may try to post some pics to get some opinions on the conditions of the housings. I'm hoping for the best.

Keep us posted, I've also got a lot of parts from the 12A I pulled from my 79. These sites are great for finding parts and pieces that you never could locally.

You will find a LOT of the "important-to-newbie" details on how to do stuff in the OE Manual is just not there! You will need some detail on how a certain bit should be fitted and the damn manual will just say "now install X part" - that's it! You'd be doomed just using the Manual! plus the videos just give so many wee Tricks that make it easier - and they are geared to us garage do-it-yerselfers.

Couple of tips -
check out Pineapppleracing.com's site - they have a few videos (free on-line) that offer some good tips AND they have the necessary tools to
1) check that you have gotten your newly assembled engine sealed up properly (pressure-test valve attachment)
2) guage to measure the Dreaded End Float, which you will learn all about off the videos.

Stu Aull
80GS
Alaska

Well the motor is out and the external components removed. My flywheel stop should be here on Thursday so as soon as that arrives I will get to see the shape of the internals. The gaskets so far have been in very poor shape so it was definitely time to be gone through. Any thoughts on gasket kits? I was gonna go with the atkins. Price just jumped from $265 last week to $300 this week. I asked Dan if he would honor that price and he says he hasn't changed pricing in 8 weeks. My internet history begs to differ. Are there even any other options out there? I looked at Black Dragon but I like the Atkins kit A because it includes new springs. Looking forward to tearing in to it this weekend. Hopefully my parts washer arrives by then.
http://i1181.photobucket.com/albums/.../RX_Update.jpg

I got the engine tore down this evening. Everything looks good with the exception of the rear housing. All damage is on the bottom. If anyone has a rear rotor housing in decent shape please let me know.

http://i1181.photobucket.com/albums/...8/IMAG0013.jpg

will take a look at what i got

that housing is done for unfortunately. Not sure on your budget but you can find a decent set on here for about 300-400 bucks. Or you can try and find someone that has a good running 12a thats going 13b and pick that up form them.

Huge thanks to GySgtFrank who came came through for me on the rear housing.

I have the parts washer set up now. Questions though: Can I leave parts such as the housings in the solvent for a period of time? Will this hurt the chrome surfaces? There is a lot of build up so I thought it woud be good if I could let these parts soak overnight. Thanks

It would depend on the solvent that you are using, as some are harsh on aluminum

I got most of the parts cleaned up this past weekend. Took a lot longer than I thought it would. I ordered the rebuild Kit A from Atkins this morning. With any luck I will be putting things back together by the weekend. Here are some pics from last weekend.
http://i1181.photobucket.com/albums/...8/IMAG0024.jpg
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http://i1181.photobucket.com/albums/...8/IMAG0021.jpg

I'm kicking around the idea of painting the engine before I put it all back together. What are your guys' thoughts on that...pros/cons. If I do paint it I would like to take the parts down to Hedahls and have them blasted. Whats the best way to protect the chrome surfaces. I was thinking of using the blue painters tape and telling the guys to be extremely careful. I suppose I could even put a layer of duct tape over the blue tape. Any thoughts/comments are appreciated.

Unless you are talking some fancy paint work, I just rattle-canned mine (black, sue me for lack of imagination....). Frog-Tape (new green tape for masking sold at Lowes, etc) was great, with some newspaper to cover the combustion areas...

Stu Aull
80GS
Alaska

Thanks Stu. Here is what I did last night. Two layers of the blue painters tape. I had an extra roll so that is what I went with. I'm gonna run to Hedahls after work and see what they can do. I just want to get the areas that are hard to get to with a brush cleaned out before I paint. Probably do a silver/black scheme.
http://i1181.photobucket.com/albums/...8/IMAG0028.jpg
http://i1181.photobucket.com/albums/...8/IMAG0032.jpg
http://i1181.photobucket.com/albums/...8/IMAG0031.jpg

Thermal Reactor
 

I need some advice on the thermal reactor. It looks to be in tough shape and last night I noticed that one of the inserts(?) was broken. Where can a guy find replacement inserts. See pics below.
http://i1181.photobucket.com/albums/...8/IMAG0033.jpg
http://i1181.photobucket.com/albums/...8/IMAG0034.jpg

Your still going to cover the coolant ports on the housings/irons right? You don't want paint in there. Just the outside of engine! Sorry I don't have any input on the thermal reactor.

Yes I will cover those before painting. this is my prep before I take them down to get sand blasted. I covered the chrome surfaces and will tell the guys to not even come close to blasting around those areas. It's just a little extra insurance in case they slip up!

I did a little research on the thermal reactor and it looks like the easiest option is to ditch the unit and go to a header. I saw a couple different options available. One from racing beat and one from pacesetter. I know nothing about either company. Pacesetter looked to be a little more affordable. I am not into racing or anything. Would like to keep the car as close to stock as possible.

If going with a header get one from Racing Beat, pacesetter is not very good. Also I have an extra exhaust insert that your looking for, PM me if your interested.

Subscribed!

Picked up the parts this afternoon that I took down to get blasted. I was pretty happy with the work. Of course it took them longer than they expected. They guy who did the work used to have an rx so I was confident he wouldn't screw anything up. Here's what they look like:


http://i1181.photobucket.com/albums/...8/IMAG0041.jpg
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I noticed you had the irons blasted. Be very careful to ensure all the blast media is removed from every little area. I blasted my housing and irons and powercoated then only to find out I did not remove the blast media completly. The result was grit in the oil pan, brand new rotor bearings and stationary bearing ruined, and esentric shaft runied. I will never again media blast irons or housings. I found the best way to clwean them was a wire wheel. I thought I did a good job of getting the blast media out. I was wrong.

I have a rb header and pre silencer and rb intake and holley carb if your interested

Thanks for the tip. I was thinking the same thing as I removed the tape from the parts. The stuff gets everywhere. I'm gonna run them through the parts washer one more time and then wipe everything down as best as I can and then blow through everything with an air compressor and then one last wipe down before assembly. Hopefully that will be enough. Thanks for the heads up.

Thanks to GySgtFrank I have all the parts now for assembly. I got everything washed real good and painted. I started assembling this morning. Everything is going smooth so far with exception of a broken oil control ring. If anyone has the outer oil control ring I will gladly by one from you. Kind of sucks because this will surely set me back some time. Those outer oil control rings are a bitch to get in. To make it even worse I had the thing in, then realized it was upside down, then it broke as I was reinstalling.
The housing I got from GySgtFrank was in real nice condtion. Better than the other one I am using. That one I am using has some corrosion close to the inner water seal but I am going to go with it.

Hopefully some one can help me out with that oil control ring. Would it be the same as the 13B? If so could I get one from the dealership?
Thanks

thanks for the pics

I found an oil control ring and it should be here today. Hopefully have everything sealed up tonight and start putting the other componenets back onto the engine. Here's what the paint job looks like:
http://i1181.photobucket.com/albums/...8/IMAG0051.jpg

Looking really good! Love the pictures. Good luck on the reassembly.

If it looks that nice INside you will be in good shape.

Have you figured how you are going to do the end float yet? Did you buy a dial-gauge or...?

Stu Aull
80GS
Alaska

I honestly wasn't even sure that I would check it. My videos all stress it but I was telling myself in my head that if it was fine before the overhaul it is fine now. I'm guessing that it is more important than I realize. I am going to give O'reilly's a call and see if they have one for rent. I'll also check with a couple coworkers who do work on vehicles. Where's the best/quickest place to find these spacers? If I have to order them and they are relatively inexpensive I would just order a couple different widths and get them on their way. During the build I've found that the most difficult part is waiting on parts to get here. Thanks Stu for calling attention to something that needed to be addressed!

Habor Frieght has dial indicators and bases really cheap. End play must be checked.

Here's an update on what I did over the weekend: Got the front end assembled, oil pan put on. Also got the alternator and air pump put back on. It was a oain in the ass but I got the old pilot bearing removed and replaced. I had to grind down the end of it because it was too wide to fit in that small of a pilot bearing. Hopefully the guys that rented it to me don't mind. I didn't take off to much. I also was able to track down a dial indicator and thankfully the end play falls smack dab within spec. Tonight I am hoping to get the thermal reactor and carb/emissions hooked up. I will review the rats nest removal document and decide if that is something I want to do. I've heard arguments for both sides. Oh and I do have a question on the thermal reactor metal gasket. Am I just supposed to drill out the two holes that are not cut into the gasket? See pic below.
http://i1181.photobucket.com/albums/...d/IMAG0074.jpg
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Looks to me like you got the 81-85 12a exhaust gasket, looks like it should work if you drill out the smaller holes.

This is nice work. I wouldn't put the thermal reactor on yet. I like to save it until the engine is in the car. It gives a little extra room to move around when putting the engine in. Once the engine is mounted, I put the exhaust manifold on and put the nuts on just a little. I then mount the exhaust to the manifold. This give a little wiggle room.

I also like to put the intake and carb on before installing the engine. Don't torque the intake bolt/nuts to much though. It's a bitch when you snap one off.

Nice work. When you turn the motor over by hand does each chamber make compression? Did you pack the oil pump with grease or Vaseline so it'll seal and draw oil on startup? Media blasting with baking soda is a good idea since it is water soluble and will dissolve away when cleaning.

I was able to get it to fire today. Put in a good 6 hours on hooking everything up. Throttle cable was a bitch and I need to figure out how to get the main exhaust up to the thermal reactor. I played a little with the timing but still can't get it to idle. I'm clueless on how to go about timing. Do you think the engine not idling has to do with timing? If the car runs at a higher rpm does that mean I am close on the timing? I also need to check all my vacuum lines again. I am not sure they are 100% correct. I don't fell like messing with it anymore tonight. I'd appreciate any thoughts and I will hit it again tomorrow. Thanks

I am assuming that you kept the original nikki carb, if so did you rebuild it? Did you try adjusting the idle mix and idle speed on the carb? how high is the rpm at idle? setting the timing is simple, rotating the entire distributor controls the leading and sliding the vacuum pod in and out controls the trailing, the first mark on the pulley is the Leading mark and second mark is the Trailing.

Yes I am using the original carb. Didn't want to attemp a rebuild until I knew that everything else was working correctly so it would be easier to troubleshoot if I had problems getting it running.

I am thinking that things aren't quite right with my vacuum hoses. I actually have an extra piece that I just realized isn't installed yet.

http://i1181.photobucket.com/albums/...8/IMAG0088.jpg

I lost mu phone about a month ago and it had all the pictures that I had took before pulling things apart.. Would someone be willing to send me some close up pics of the rats nest/carb so that I can make sure my hoses are all going to the correct places and to help install the piece shown above? You could either post them in the thread or if your not setup to do that you could e-mail them to jason.brekke@gmail.com I would really appreciate it!

that extra piece of vacuum line is what I think connects the charcoal canister to the ventilation check valve. the top part that has the larger bracket connects the the top of the air cleaner, the middle outlet connects to the air vent solenoid which is located between the fuel inlet and omp inlet on the carb, the end of the line goes to the vent check valve.

Thanks man. I had the first two connections right but just didn't know about the one that goes to the vent check valve. I did some googling and came across a link of a guy asking for the same pics I was looking for so I don't need pics anymore. http://www.cardomain.com/ride/211469...da-rx-7/page-4


I got everything hooked up and played with the timing a bunch and got it idling smooth. Went for a little spin tonight. Still got some fine tuning to do but I am happy to have the thing back in one piece and running!

I cant seem to find any marks on the pulley. It is pretty work and has some surface rust on the edges. Any ideas if these marks are missing?

The timing marks on the main pulley wear off as the car ages but it also has the marks cut into pulley itself, just rotate the pulley by had and feel/look for the marks and once you find both marks just paint/color them in, its best to use 2 different colors to tell the difference between the leading and trailing mark.

and i would do an oil change on the engine after about an hour of runtime due to the bead blasting, just to be safe.

What are those holes in the old housings anyway? I just picked up a '79 motor and noticed those right away. Do you need to plug them when not using a thermal reactor?

Very nice build by the way! Can't believe how clean you got everything.

they are to feed air from the smog pump into the manifold at various times.

Just changed oil tonight. Probably a good 30 minutes on the first oil I put in. I will probably do it again after the first tank of gas goes through it. Cheap insurance they way I see it.

One more question on the timing. I was able to find the leading and trailing mark on the pulley after seeing a picture in the FSM. However, the engine would not start after following the steps in there. After pulling the distributor out and trying some other random drop ins I was able to get it running and idling. Question is, on the 12A is it possible that the timing marks on the pulley could be off say, 90, 180, or 270 degrees? I can't remember if the pulley location would be locked in due to a key or if it could be in one of four positions.