Frogman

After long consideration Iv finally decided to pull the 12A out of my CA 1979 Rx-7 SA .
I have a worsening dowel leak , ATF fluid leaking from between the bell housing. engine and a bad coolant leak originating from failed O rings on the intake manifold.
I want to do as many SMOG LEGAL reliability mods to the engine and periphery functions as possible as I plan on making this car, my daily driver.

I know nothing of rotaries so any advice on what rebuild kits/gaskets ETC I need Is appreciated. Iv already watched a couple of dozen " how to rebuild a rotary" videos and it seems it's easy as long as I prep beforehand and have the right tools to measure clearance etc. everything should be fine.

My car has no electrical issues and I would like to stay away from electronics as much as possible ( no modern dizzy conversion crap) as i have a good grasp on how this car electric systems function and how to test them at this point.

In response to GSLSEforme il just lay out what I'm looking answers for

1. cheapest /most reliable rebuild kit
2. cooling mods
3. reliability mods to prevent dowel pin leaks. future leaks
4. Longest lasting apex seals for the occasional spirited drive
5. **** I might as well replace now !


Things Im happy with
1. My distributor system
2. My carburetor =) works great and I have a NOS one if I ever need a replacement

GSLSEforme

No intention of contradicting your"no modern dizzy conversion crap"...as periphery functions that're rock solid and relatively inexpensive go,an FB electronic ignition conversion is top of this list and you will find many forum members who will chime in to this effect.
Reasons for:much more powerful than points/condenser system. Easier starting ,better driveability,more power.
:no parts to wear out and retard ignition timing as they do so...point faces/rubbing blocks. Electronic ignition is truly set it and forget it,nearly 0 maintenance,Dist cap and rotor is it.
:Properly,professionally installed,no smog tech will detect it.Only slight difference in appearance from points type and electronic ignition ignition type distributor. Points resistors can be left in place and source voltage can be taken from their connections.
:Added benefit,this conversion will make engine run cleaner and help it pass that cali smog test.

Reasons against:if the need to keep car original overrules all the positive benefits outlined above...you'll need to decide that for yourself.

Let's see how others weigh in on your thread.Fairly certain others will chime in and suggest you swap that automatic for a manual trans. Easy to do,manual trans is much more fun to drive and when you drive it with a manual trans behind the engine you will see exactly how much that auto saps the power on your engine. So...more usable power,bigger fun factor. You could buy a rusted hulk and harvest all the components to do the swap for @ $500.

Frogman

I've read threads on people doing dizzy swaps and it seems like a headache having to splice cables. Besides my car's electric system works fine. Maybe in the future il mod it but right now I'm mainly looking for parts i can swap/ what the best-rebuilt kit/seals are ( Atkins, pineapple racing, if atkins or OEM seals work best, if i need new rotary bearings, if the brown Atkins seals are better than OEM" . Also, I already secured a manual tranny for 120 USD. AFIK the automatic cars are rarer and they go for higher resale value than being natural one does online, then again my car has 110k miles on it .

No electric mods RIGHT NOW , IM looking strictly at reliability engine modifications and as stated above, aside from my battery dying a lot ( car has not been driven in over a year) the electric system seems fine

KansasCityREPU

iTrader: (9)

There aren't that many smog legal reliability modes you can do. Going to elect dizzy is one of them. You can even use a later model dizzy harness and not chop up the current one. makes it easy to revert back if you ever have to.

There's someone on this forum, can't remember who, that switches out their entire Racing Beat exhaust to factory to pass smog.

Frogman

Are there any 12 Reliability mods I can do? I heard people have a irons mod to eliminate dowel leaks.

KansasCityREPU

iTrader: (9)

There are a few mods you can do when choosing engine parts like one piece apex seals, 3rd gen corner seal springs, etc. It really depends on the application and power. If it's just a basic 12A rebuild, I'd start with a factory rebuild kit and include apex seals, one piece corner seals and 3rd gen corner seals springs, oil pressure regulator mods, a certain year oil pump is best, etc.

I'm not an engine rebuilder, have only done one myself, so there are others with better info.

GSLSEforme

Pretty sure that's LongDuck with his Se,switching back and forth between his cat converter and Rb presilencer every 2 yrs.

GSLSEforme

"aside from my battery dying a lot...electric system seems fine"...electrical system might need some attention,lol.

Frogman

I haven't driven the car in over a year and it holds an arge from running idle 30 mins for over two months. I think its fine =p

Frogman

I heard solid seals were bad? that they put more wear on the engine ( heard on the youtube comment sections , you seem more knowledgable than me )

KansasCityREPU

iTrader: (9)

It depends on the application and goals of the engine. For example, a heavily ported engine or bridgeport might want to run a one piece because of the risk of dislodging a two piece.

j9fd3s

iTrader: (3)

1. most reliable is the OE Mazda kit. if you buy it right it isn't any more expensive than anything else.
2. have the radiator cleaned/rodded out, buy a thermostat and hoses from Mazda, and you are good to go.
3. none really, they are just 40 year old Orings, replace with the new... the new ones are a better material
4. longest lasting is probably the Mazda seals.
5. in addition to the water hoses, you should do the engine mounts and trans mount, and anything else that looks suspect.

Frogman

Where can I get an OE set ? I though Atkins rebuild kit was OEM minus the optional stuff

7aull

iTrader: (2)

My 2¢
-don't think the 79,80 SA 12A kits are avai. Period. But - FB 12A same except you will need to buy the diff intake mani (including 'O' rings!) and exhaust (reactor) gaskets, the rear reactor-to-mini-muffler gasket and the 2ndary air pipe gasket that attaches to the back of the intake.
These are avai separately, if not from Mazda, they are all over ebay quite cheep. Mazdatrix is a good source for Mazda OE engine bits.
-both Atkins and Pineappleracing.com offer there own 'improved' water seals, I chose the Pineapple's. Obv Mazda kits come with these already, but for me, the extra $75-ish at this point in a build is good piece-of-mind, esp considering these water seals seem to be a weak point.
-check your OMP lines and their rubber attachments for failure. I think only the LONG line is still avai new.
-Videos:
Atkins, mazdatrix and an outfit in New Zealand have great DVD videos on builds. I bought all THREE to be sure I got the max info.
;D
They deal with the 13B but diffs are minor. If I had to buy one it would be the Mazdatrix one. $30 well spent.

Stu Aull
80GS
AZ

Frogman

Do you think If I call up Atkins they can swap out the correct gaskets for my car? . Like the 79 spec stuff since its interchangeable and in most cases also cost less

Frogman

Which parts from this kit do i need/ not need . ( i know the first two gaskets AND o rings dont fit my car, already checked art numbers via the FSM)

j9fd3s

iTrader: (3)

the gasket set is N201-89-100B list price is $145

you'll need 0820-10-605 front main seal
1668-10-556A rear main seal
3743-13-111B intake manifold gasket
and a tube of silicon, preferably the grey or black stuff

Frogman

Ok so so far I've been going at a snail's pace ( restoring body parts as I take them off, labeling everything with a white paint pen marker/labels) . My oil cooler mount on the driver side is busted, the rubber separated from the metal ( rust). I'm noticing two odd things. Someone was down here before and there's a lot of taped up cables, I'm starting to think my car has an electronic dizzy ( it explains why the car turns on like a charm when all of you complain the car has to warm up and ****). SO I'm taking pictures and going to see if y'all can identify what this is.

But my main question is, what wrench/bolt size is the oil cooler lines? And how the hell do I remove them since there two bolts ??

7aull

iTrader: (2)

Remove them at the ENGINE end!!!!
I would leave attached to the cooler. H-U-G-E heart-aches for those who tighten the FMOC end of the line too tight (cracked cooler).
Would buy new cooler rubber mounts - still avai (!)

Will let others note the wrench sizes...

Stu A
80GS
AZ

Frogman

Good idea, also I'm not paying 34#$for a piece of metal, I'm just gonna scotch ultra grade double-sided tape that bitch. ( I'm guessing the original part is rubber + adhesive to metal)

7aull

iTrader: (2)

true, but they are surprisingly durable - my original set went 24yrs, and were still holding well but signs of cracking at the time.
Pretty good value over that many years! You really don't want an unobtainium cooler banging away against metal if/when your home-brew fails

Stu A
80GS
AZ

Frogman

my oil cooler has probably been resting on the oil catcher for years with zero issues. I will give the tape a 100-pound stress test in the sun and with a heat gun if it fails il buy it . The scotch heavy duty double sided tape AFIK is incredibly durable.

Frogman

The question, is there any plug and play aftermarket oil coolers? The more I dig the more I find wearable parts completely deteriorated. Car needs new bands/motor mounts, tubing, etc. I keep questioning why imputing money into this and not the match one sitting right next to it, god I love rotaries!

7aull

iTrader: (2)

For FMOCs there "is" a replacement offered from china on ebay. NO idea what the quality is like, but under $100.
I recall the OE cooler has a fitting internally that regulates...pressure? - and doubt the chinese versions have this feature.
And my own experience with chinese rads (water, for me) is they "almost" fit. The sizing and mount points were off just enough to be annoying, to be kind, and required mods io install,

Unless you think your OE cooler is toast, I would send it off, have it sonically cleaned (the aircraft industry does this all the time for small planes), and reuse it. If its not damaged, it should last a lifetime as they are really well made. Opt 2 is PU a used one off the classifieds.

As to "wearables", can you really be surprised on a 40-ish yr old car?? Do what I did, ID everything in the car that is either rubber, or has rubber components, and replace it. Incredible peace-of-mind, and really, you are only doing the Old Girl right by renewing these antique parts. She will reward you with another 40 yrs. Or at least have a leg-up in trying!

Stu A
80GS (yep, pretty much all new rubber everything...)
AZ

KYPREO

The OE oil cooler has a built in pressure relief valve AND thermostat. Aftermarket do not and you can end up with massive pressure levels when cold and blow oil cooler lines. The OE oil coolers are also very well made and effective. The only major flaw is that the hose connector bosses are located on the front of the end tank and tend to flex and crack when removing overtightened or stuck hoses. The FC design has the connections on the top and side, with a bar to lock the banjo bolt when undoing the bolts. This prevents flexing of the bosses and avoids cracking. If you were going to "upgrade", the FC oil cooler is a good choice.

I agree with 7aull. Keep the OE cooler and get it reconditioned if required.