isamu

Did Mazda make a 12B engine in 83 and 84? Is this engine a few cc bigger than the 12A? Just curious, I remember reading somewhere about a 12B engine, but I can't remember where. Thanks.

rohlfr

Whats a 12B is the question everyones asking? Here is a rough and dirty mazda engine history

10a:late 1960's-early 1970's

12a turbo:1983-1985

12a:early 1970's-1985

13b early style:1970's-1978

6port 13b:1984-1992

TII 13B:1986-1992

13b-Rew:1993-1995USA '93-present japan

Renesis:95 Prototype still in the works



basic difference between 12a and 13b is

12a:1146cc displacement

13B: 1308cc displacement

isamu

Thanks rohlfr.

What I was thinking of was the 13A engine that I had read about before. I got mixed up and thought 12B was the engines title. I went and looked over Felix Miata's page and found the reference to the 13A. I saw an add for an 85 Rx-7 and it stated that the car had a 12B engine. Probably just a mistake in the script, should be 13B.

Wooffinn

Hi Isamu, wooffinn from downunder. The answer to your question on the 12b engine is kinda yes and no. In my part of the world our series two, released about mid 1981, had a upgraded 12a in trems of cc capacity and port design. Most people say the mods were to try to get maximum horsepower with all the emission control gear on the engine. As far as we know it was merely a code name mazda gave to the engine as I've never seen any housings stamped with '12b'. Basically a 12a 6 port engine. As you said it may just have been a misprint, but a few mazda people over here have heard of that engine too.

Wooffinn

Hi Isamu, wooffinn again. Sorry mate, I've gotta chuck a spanner in the works!! Mazda actually released an engine called the 13A. It was a VERY rare rotary engine fitted to the R130, or Luce rotary coupe in Japan, in around 1969. The R130 was actually a Front Wheel Drive(no I'm not having you on!! , and the 13A Actually had a different shape and height epitrochoid curve, (All the common Mazda engines have the same shape and size curves, just different width housings), to be able to fit in th FWD set up.Unusual but quite stylish coupe, kinda a mix of R100,110s cosmo and Rx2.