bugman1973

here is yet another question for all my fellow RX-7 owners. i cant really decide which motor and fuel set up i should go with. i have found a motor and i have my stock motor. the motor i found is a 13b out of a 85 Gsl-se miles unknown. i think it is a 6-port, the motor is fuel injected but i can change that very easily. I can put that in it or i can put in the stock motor but just rebuild it.

Rx-7Doctor

iTrader: (13)

The question you have to answer is. Do you have to go thru emission testing? If the answer is yes. Then I would stick with your 12a. If the question is no and you want to get alot more Hp by using the 13b, then that is the route I would go.

Rx-7Doctor

iTrader: (13)

Or option B. Get the 13b motor. Street port the 12a irons and use the 13B rotors and housings and get the best of both worlds. Which is a 13B 4 port motor. That is of course if you don't have to worry about emission testing.

bugman1973

no emissions to deal with. all i have to worry about what would be more cost effective. the rebuild will cost about 1100 dollars and the 13b is going to be about $400 and if it need to be rebuilt or i need a carb or a mega squirt or something

trochoid

iTrader: (6)

Questions you need to decide/answer for yourself. What are your hp/performance goals, what is your budget, what are your mechnical skills, do your prefer working with carbs or FI. As you answer each one of these questions, you will narrow down your choices

firestarter810

Please educate me on this build. I have a 12a in my car, and a 13b from and S5. I was considering swapping the entire S5 motor in, but I've been told there are some hassles. This afternoon, I was considering having the 12A rebuilt. Now you tell me this.

Can I build the motor as you describe? Can I use the S5 fuel injection, or would it be better to retain carb'd, albeit with a carb upgrade? What mounts would this hybrid sit on? Now I'm gonna have to start searching on a whole new tangent...

Rx-7Doctor

iTrader: (13)

Look down a few threads to the 12a and 13b thread.

firestarter810

thanks!

Rotospeed

iTrader: (8)

hey i was thinking about building that 4 port 13b. is that going to be a big problem passing emissions??

trochoid

iTrader: (6)

Yes.