Dillon

Whats the difference between a 13b and a 12a besides the carb? Does the 12a have a 2 barrel carb?Will a 12A bolt up to second gen tranny? Does the 12A have any 5th and 6th ports or anything like that I have to watch out for?

NZConvertible

The 13B is bigger than the 12A (1308cc vs 1146cc) becuase it has narrower rotror housings, making it 20mm shorter (meaning none of the 13B intake and exhaust manifolds or engine mounts match up). The 12A has a 4-barrel carb, yes a 12A will bolt to a 2nd Gen gearbox, and yes the 1st Gen 12A has 6PI (six-port induction).

Please don't say you're considering putting one in an FC...

snowball

you know NZ, carbs are the wave of the future.

Dillon

is the 5th & 6th port always open or is there something thats controls them like the airpump or exhaust?

Dillon

what would have to be done to mount a 12a into a second gen rx7?

K-Tune

iTrader: (26)

cant be done without major work, there aren't provisions for motor mounts like an FC chassis uses.

a 12A is a 4 port engine like a turbo, there are a few VERY RARE examples of a 6 port 12A.

Aaron Cake

iTrader: (1)

The major differences have already been mentioned....

However keep in mind that the 12A mounts on the front cover and NOT the center iron like the 2nd gen 13Bs. So really, it won't fit unless you make some custom mounts. The 12A is also about a 100HP engine, so in a 2nd gen it will be SLOW. You're going to need to downgrade the car to run with a distributor, replumb the fuel system for the low pressure needed for the carb, make a custom exhaust, etc. So all in all, it's totally a bad idea.

NZConvertible

Yeah you're right, my bad, the SA's 12A is 4-port. I was thinking of the Japanese 6-port 12A. They're not that rare in Japan.

Valdez

iTrader: (1)

I have a 12A in the 88 I just bought. It doesn't look that hard to do. I imagine it woud be much harder to install a 13B in a first gen, especailly with all the extra wires. Hooks up fine to a second gen transmission.