12A vs 13B
 

hey guys i have a lil question... it there much differance between a 12A and a 13B? i mean, im very new to the whole rotory thing. and iknow there r differances... but and at my local junkyard theres a 12A sitting in the back room.... he wants 150 bucks for it (i dont think he knows wut it is)... now i was thinking, i know its not a 13B, but if i were to buy it, and pull it apart, are the internal workings close enough to a 13B that i would learn something bout my own motor? Or is a 12A so completely differant from a 13B that it would just be a waste of my time?

The internal workings are very similar.

well the internals are the same enough for learnings purposes i.e. this is a rotor - this is an apex seal, this is a stat gear etc.

But really nothing will interchange that Im aware of

They're basically the same. Offer him $100 and have fun playing with it.

awesome thx guy... i think ill go grab my new motor and let the tinkering begin..lol

INternal workings are the same, its just carb. The rotors and housings are 10mm shorter than a 13b, and its a 4 port engine.

What about at 12AT vs. 13BT???

what about them?

The bocks are exactly the same, 12A's are very slightly smaller, and they are four port, as opposed to a six port 13B, however four port 13B's do exist. Yes for learning purposes, this is a great idea. The internal workings are identical.

if it has four spark plugs does it make it a 4 port

When they talk about ports they are talking about intake ports. As far as I'm aware all rotary's have a leading and trailing spark plug.

The ports are the intake ports. In the US all rotarys had 4 ports until the introduction of the 84/5 FI 13B that came in the Gsl-SEs. From then on, all NA 13Bs were 6-ports and the turbos were 4-ports. The extra 2 ports are in the secondaries and opened up around 3800 rpm. The early 13Bs, 74-78 were 4-ports.

The European market got a 12A 6-port, but the secondary ports were butterflys while the 13Bs have a rotating sleeve.

The general configuration of the internals are nearly identical between the 12As and 13Bs. If you can build one, you can build the other

The Renesis, very early 12A/Bs and 10As are not included in my list as they are a bit different.