johnstan

I bought a 1983 Rx7 with 108,000 miles on it last summer. It has been a great car so far and I hope to have it for a long time. I decided to rebuild the stock 12a engine this summer because I have no idea how well this car has been treated in the past. So far I've been able to get the engine out and take it apart. I have several questions about where to go from here. I was wondering what you guys used to clean the engine enternals. I have watched Aaron Cake's video. Is his process recommended by others? I was also wondering what need to be replaced. I know I will have to buy a new gasket and O-ring set but what about the apex seal, the side seals, and the corner seals. How can I tell if they are worn out? I am on a budget so I would like to reuse them if they are ok. I have read it is good to replace all the seal springs. Is that correct? I was also looking at the one piece corner seals and the improved springs. Is that a good investment? Where should I order the parts? I have been leaning toward atkins because they have the best prices I've seen and you can order the parts seperately. Are there gaskets and seals good quality? Here is some pictures.





Does my housing look ok from what you can tell from the pictures?One last thing. I have been looking into a 13b swap, but I have read so much about it on this site I think I have overloaded myself. What parts should I be looking for to do this in the future or is it something that I can do while I have the engine out now? What kind of 13b engine should I be looking for? The TII egine? I would like it to be feul injected and a turbo would be nice. Does anyone use the twin turbo out of the 3rd generation? Thanks for all your help in advance.

81WideMariah

iTrader: (8)

What's your budget for this build/rebuild? That will largely determine what will be replaced and what will be reused.

FunK73

iTrader: (6)

my $.02 is if youre in there, you might as well do it. No sense in taking everything apart again later or blowing an apex seal and trashing the engine.

As far as checking the seals, there are specs for each one in the FSMs.

Housing shot isnt real clear. I would say try cleaning everything up and go from there. No point is judging how things are when theyre all covered in junk =)

74RX4

iTrader: (10)

Mazda lists tolerances for most of the internal engine parts in the engine section of the FSM. You can use the 84 manual for your engine. I use Gunk "cold parts cleaner". Comes in gallon cans at parts store. Foil bread loaf pans from the grocery store let you soak the rotors one face at a time. I soak each side overnight. Much of the carbon wipes off afterward. I always replace all seal springs. They are cheap. I get mine from Mazdatrix. Soft seal kit from Rotary aviation. If you are going to reuse the seals its a good idea to keep them in order so they go back in the same place on the same rotor.

johnstan

I don't have a fixed budget, but my side seals and apex seals look fine. I just don't want to spent $1,000 on seals unless I need to.

81WideMariah

iTrader: (8)

Took the words right out of my mouth..... that's all the advice you'll need.

Except, I'd recommend you get an engine stand and an adapter for a rotary engine.... it will save you a TON of grief and aggravation when it's time to reassemble. Also, Aaron Cakes video is awesome... but I also recommend the Mazdatrix video... for $20 you can't beat it.

Rotary-MG

iTrader: (1)

I bought the Mazdatrix rebuild and porting DVDs. I think they are great. I immediately converted them to divx files so that I could play them on my computer without the DVDs (not for filesharing, sry). In the Mazdatrix vids, they are against using vaseline on the seals since it's petroleum based and can cause the rubber seals to expand. Aaron can't seem to get enough of the stuff, lol.

Mazdatrix also walks you thru examples of bad housings and areas to look at for common problems. For example, chipped chrome on the rotor housings is bad, heat damage, electrolysis along the water passages...

While you have the engine apart, are you going to consider porting????
Won't a ported 12A win out over a stock 13B? (oops, I'm getting off topic)

I think the car will track better without the ladder in the engine compartment. - sorry couldn't resist -

81WideMariah

iTrader: (8)

Aaron, and most other rotary engine builders, use vasoline or grease to hold in the side and corner seals when installing the rotors. It keeps the seals, especially corner seals from falling out or rotating when the rotor is flipped face down. What you don't want to do is use vasoline on the water jacket O-rings. The FSM reccomends using vasoline for this, but you should use Hylomar instead.

johnstan

Thanks for your porting suggestion. I'll read up some more on it. It would definately be cheaper. I guess I should take my first rebuild one step at a time. What should I use to clean the engine and are atkins gaskets and o-rings sets good quality? They are the cheapest I've found. I open to any and all suggestions. Thanks.

7aull

iTrader: (2)

As said - ANY instructional DVD video you can get will give you ALL the details and tricks you need to know. These are pretty easy engines to rebuild if your at all mechanically inclined but there are numerous "tricks" and "gotchas" that if missed, will blow up your rotor-motor, so get informed:
Atkins-
Mazdatrix-
DIR-RE-
All make good DVDs - Mazdatrix is best for the $$ and it will save you a TON of grief (and, therefore: $$)!!!

Mazda, Atkins and Pineappleracing all sell rebuild kits (ie gasket kits) for $115-130.
Beyond that, you _may_ need:
-Apex seals
-new rotor springs and seals
-oil control rings and seals
and - heaven forbid:
-housings if yours are beyond re-use

DVDs detail all this stuff and what to watch for...

If you plan on keeping the car "forever" you might consider pineappleracing.com 's
Upgraded coolant '0' rings set. $$ but considering this is the area where most rotaries fail, its a great investment.

Going down this road too!
Stu Aull
80GS
Alaska

bugman1973

ive done quite a few rebuilds but the one lesson i have learned is that if you take it apart and your not sure how long the seals and springs have been in just replace them ive lost an engine to just this. not fun and more costly in the end

JMB

I will be following this thread closely. Good info here for a first time rebuilder. I am in the same boat as the OP.
I just purchased the Atkins Rotary DVD and should have that by Thursday. I may even start pulling the engine this weekend if I am ambitious enough. Good luck to you OP on your rebuild.

johnstan

bump. hey guys i recieved all my parts and dived in to the rebuild yesterday. I hit a roadblock though. I can't keep the small triangle apex seal piece in while I'm trying to put the middle block in. I bought the one piece corner seal from atinks. In the videos I've watched, when people plug their 2 piece corner seal it looks like it helps hold the apex seal in. Please Help.

Jeff20B

iTrader: (13)

I just started doing this to keep the little triangle end pieces in place. Super glue or crazy glue. Sounds crazy, but it works. Make sure to do it on a very flat piece of glass or mirror. Don't use too much. Trim off the excess with a razor blade. Test fit them in the slots to check for easy installation.

Also make them just slightly shorter than 70mm so they go in without causing the side plates to stand off as you're torquing the tension bolts. Yes, some will snap apart during torquing, but for those ones that don't, like right at the edge of being too long, like 70.010, they're the ones that I've had some confusion about. They cause the engine to be hard to crank by hand.

I've built enough without glue to know how it's supposed to feel, and that one felt weird. The more recent one I just did last week had them slightly shorter and it spins over by hand perfectly. Now I just have to get all the intake and waterpump stuff on to see how easily it starts.

By the way as soon as it starts, the glue goes away. Yep. Either the heat or the little bit of oil/gas mixture that contacts it makes it seem like there was never any glue. It was hard to start at first, but a little oil down the carb solved that. Then every successive start was fine; just that first start was the only tough one if you're using glue. That's been my experience.

74RX4

iTrader: (10)

^ That's how I do it.

DivinDriver

iTrader: (15)

Yep. Superglue is a necessity if you don't have the dissolving carbon "helper" pieces on your apex springs, & makes it easier even if you do. But you want a tiny, tiny amount.

rx71king

iTrader: (6)

krazy glue all the way......cheap insurance

rxtasy3

iTrader: (2)

when i did my build years ago those came already glued together.

johnstan

Thanks guys! I'm getting back to it today. I'll let you know how it goes.

j9fd3s

iTrader: (3)

aaron uses way more vaseline than he needs to, it must smoke for an hour! i don't use vaseline anymore, i just use a daub of the same grease i use on the bearings and side plates, if anything.

81WideMariah

iTrader: (8)

I agree... I use assembly lube for all the bearings and a little bearing grease for the seals. I use a little extra assembly lube and bearing grease if the engine will not be started immediately so that hand rotating doesn't take a toll on the housings and plates. I also crank the engine over a few times before turning on the fuel pump so that oil pressure builds in the bearings and E-Shaft, this will take alot longer on cars with FMOC's if they were drained during engine removal.

johnstan

Hey. Thanks for all your help. The super glue worked great. I have the whole engine back together now. I just Have to drop it back in the car.

Jeff20B

iTrader: (13)

Glad the glue worked for you.

Hey you're almost as far along as I am. So far the engine is in and the starter is bolted up. Oh and the exhaust is too. Waterpump and intake are next. Can you get yours running before mine?

johnstan

Hey guys. I'm sorry to say I still don't have my car back together. I went on vacation and then went right back to school (study, study, study). I've worked realy hard and got a full free day today (I'm out of school for labor day ). When I put the engine together a month ago, I torqued down the tension bolts to the hayes manuel's suggested 25-27 ft/lbs, but the engine did not turn "light and smooth" like it was suppose to. I had to put the flywheel on to get enough leverage to turn the engine at all. I just need some help trouble shooting. I'm going to borrow my friends torque wrench to see if the one I used earlier was off some. Thanks for your help.

stofficer1226

Did you port your motor?