Minnionator

hey there, im sort of new to the first gen thing. spent lots and lots of time on my FCs, but looking to get a friends SA22C.

heres the situation: the car is in great shape and low low mileage, but the coolant seals are toast and he hasnt been able to work on it. car has been sitting for 6 months. im not even going to look into rebuilding the stock SA engine.

now the question:

what parts are compatible and what arent?

can i just use any 80-85 short block and all the parts from my 12a?

can i use any fully equipped 80-85 12a block?

the reason i ask is because i know about the various carb, emissions, trans, and oil cooler changes.

its going to be a bitch if i have to find a used 79-80 engine somewhere.....cuz i know of a few good later 12as.


just wanna make sure i can find a cheap engine for my car before i lock myself into it. thanks guys.

OneRotor

iTrader: (3)

if you have the option to pick up a later 12a, pick it up. It will mount right up. The differences that I know are that the SA 12a's have 6mm carbon apex seals that don't last too long, and the chrome plating on the housings is absolutely terrible as far as flaking.

Minnionator

hm a bit enspireing but not overly hopeful.

what i need is like a direct list of everything that is different or needs to be swapped over.

i live like 4 hours away from my friend who i may get the car from so i need to have everything sorted out before i get there, to avoid any if ALL surpirses.

Keeble

iTrader: (3)

well if you get the shortblock you would want the flywheel too, as far as everything else, tranny mounts, wiring should all work

JoeyMazda

The 79 and 80 rotor housings are different than 81 and up. If you're going to use 79 and 80 housings on a 81 and up you have to drill a hole down from the exhaust port to create the thermal bypass. The 79 and 80 doesn't have it. You can find out mare at www.pineappleracing.com All 12A housings are the same other than that.

trochoid

iTrader: (6)

Whoa, hold on there now. Whitey, your info is usually correct, but the 6 mm carbon seals were only used in the very early twin dizzy 12As. Did you have a major brain fart.

The biggest dfference between the SA/FB enines is the exhaust system. The SAs use a thermal reactor. Everything newer that uses a cat. Due to this fact, there is a difference between the engines as to where the exhaust feed comes from to deal with emissions. The reactor equipped housings have a drilled port, and dedicated front/rear housings, with the port near the exhaust flange to feed the reactor. The FBs have a rectangular feed port in the upper part center iron, just below a factory plug, that supplies exhaust gases through a passageway in the intake manifold to the air control valve mounted on the outboard side of the intake mani.

The SA intake manifold will not cover the exhaust gas feed on an Fb engine.

That being said, Minnionator, you have several options for installing an FB engine in an SA body. If you don't need to meet a tail pipe emissions test, headers will cover the SA exhaust feeds. If you choose to use the SA/79 intake with the FB block, either mod the flange of the intake to cover the FB exhaust feed port or plug the hole itself.

Simplest option would be to install the FB engine, carb, intake and headers with a full FB exhaust system. While it sounds overly complicated and I've gone into to much detail, the swap is pretty straight forward.

Short version is as follows:

Match intake manifolds and engines, SAs to SAs, FBs to FBs. It is possible to interchange them if one is aware of the differences. Since the components for the thermal reactor exhaust are NLA, upgrade to the FB parts. The SA intake is supposed to have better flow characteristic and is prefered by some.

silver80sa22c

glad i saw this, im in this boat right now. i have an 85 engine (the one xavier8 was selling), and i have the blown engine in my 80. i need to see pictures of where to modify the flange for the intake, if thats possible. also, not to derail the thread, but could someone direct me to where the strip down for an sa's carb is? i have found nothing but fb instructions. pm with carb instructions, if you wouldnt mind

trochoid

iTrader: (6)

There are 9 or so versions of the 1st gen Nikki carbs. Differences relate to the Series, (1,2,3), manual/auto tranny and California emission equipped carbs. That being said, the differences are minor and all of them can be found in the factory carb manual. Emissions delete for the SAs is basically the same as the FB, except for the exhaust and charcoal canister/PCV.

You don't need a private e-mail to figure it out, just some time and reading. There is a link in the FAQs for the rat's nest removal and pics in the archives of stripped Nikkis. In my sig line is a link to the online carb manual. The more you learn on your own about how the carb and it's related systems work, the easier it will be to maintain your rotary at peak operating performance.
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Minnionator

so other than modifying the thermal bypass, i can just throw a 85 (ish) short block nd flywheel on, and use all the 80 periferals?

trochoid

iTrader: (6)

Use both the later intake and exhaust if you have them. By the time you strip the emissions from the carb, there's hardly any difference. You will need to buy/make a block off plate for the ACV, and/or a plate for the fresh air feed to the cat if using the 79 intake.

OneRotor

iTrader: (3)

apparently i did, my bad.

Minnionator

trochoid, thanks for the info- my problem is, that i think finding a rebuilt short block of ANY year will be easier than trying to find a complete long block, or find a car to remove one from.


that, and if i can use a newer short block and put the older stuff on it, i wont have to do any fabbing or anything.


to put it in perspective, i live on vancouver island, BC- the car is located 45 minutes in land, on the lower mainland. i need to be able to swap something in and go, and not worry about fabbing up exhaust stuff etc. im going to TRY and look for a 79-81 rebuilt but that may be hard.


btw the car will have no thermal reactor or cat or any emissions, AC pump, or air pump. itll be stripped to nothing.

lfd75

Before buying a new block, take a look at kentetsu's coolant seal repair thread on the (1st gen) archives. It may not work but what have you got to loose.

Jeff20B

iTrader: (13)

Flywheels are different. You can't simply throw it on. You must match the flywheel to your engine year (rotating assembly).

Minnionator

yah just talked to someone about the flywheel. may try to take the one off the current engine.

also, the current engine is most likely done for. i already instructed my friend on how to do use the leak fix stuff and it worked for a little bit then got way way worse. car has been sitting for 6 months now, its likely that the entire inside of the engine is rusted to hell.

silver80sa22c

so if i understand whats going on here (and let me know if im not understanding), im going to need a new flywheel since i have an 80 motor and im swapping to an 85? i was under the impression that an sa's trans would work with the 85 engine, and in that impression i figured the flywheel would be the same. someone shine some light here, it would be appreciated.

JoeyMazda

If you're going to swap an '85 motor on your '80 you will need an '84 or '85 flywheel. That is the balance of the motor and they are not all the same.

Jeezus

iTrader: (4)

+225mm clutch on a 215 fly.

silver80sa22c

are the flywheels different for automatic trans? im hoping for a no, but obviously nothing i have hoped for is turning to reality. so i need an 84-85 flywheel and counterweight, hopefully someone on here has those for sale

IanS

iTrader: (4)

That would be an 83-85 flywheel.

Julian

iTrader: (14)

81-82 12A's use heavier rotors, flywheels and counter weights (front and rear). 83-85 the lighter set. In racing the 83-85 engine is prefered.; it has been a long time since my rebuild and I would need to go through receipts but I remember some advantage of a custom build mixing between 83 and 85 parts. fyi flywheels and counter weight are different between M/T and Auto

You MUST match flywheel to counterweights.

Kentetsu

Before you give up on the motor that is already in the car (with the bad coolant seal), you might want to check out this thread:

https://www.rx7club.com//showthread.php?t=750774

I fixed my issue by spending $4.00 and 15 minutes, and have raced that motor all year with absolutely no issues. No coolant loss at all. What have you got to lose?


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DivinDriver

iTrader: (15)

Additional note:

There is a variant of the 80 12A used only in California, that includes provision in the center plate for an EGR valve.

They can be recognized by the EGR opening on top of the block (two tapped holes and an oblong opening) that needs either an EGR valve or a blocking plate, and that the exhaust mounting area has five, not four, holes leading to the thermal reactor. The front rotor housing has an additional hole:



Good-condition 80 12A Cali blocks, and the special center plates and front housings, are rather rare, and valuable, as they are essential for passing smog. Ask me how I know

silver80sa22c

im using my 80's auto trans with the 85 motor. what im understanding is that i need an 83-85 auto trans flywheel and counterweight. the 83-85 flywheel for the 83-85 auto trans will bolt to a 1980 torque converter, wont it? im so confused, i dont know what to buy.....

Julian

iTrader: (14)

The fly wheel and counter weights relate to balancing of the internals 'rotors" so engine parts should be grouped together. Model year of trans does not effect balance, other than that auto flywheel counter weight needs to be used with an auto. Flywheel diameter increased in 1983 on models; I can not guarantee that '80's bell house has room.