Bluem

so ,i might buy a Datsun 1200 to convert to rotary, im looking for a 13b to shove in

what year 13b (carburated engine) do you guys recomend?

RotorMotorDriver

iTrader: (1)

Well, all the 13Bs that were made from 84+ are fuel injected, the only carbed 13Bs were in the 70s, and they were the desireable 4 port models. Personally, if it was me, I would try and get my hands on a fuel injected 6 port 13B from a 1st or 2nd gen (non turbo), and then tear it down to rebuild it using ported 12A plates to make a 4 port 13B. Then throw that in there with a good aftermarket carb and exhaust

~T.J.

SS124A

I have a friend with a 75 13B 4-port engine he bought new as a Mazda reman last year.. the engine has maybe 8K miles on it. He has been running it with a Weber 45 DCOE and a lightweight flywheel. the weber set-up would be available with the engine, as would be the rear C-weight (He would likely retain the aluminum Flywheel) If interested let me know.

He has considered selling it so i can build him one of my 12A's.

this would be a good place to start as the 74/75 rotor housings came with the largest USDM exhaust ports.

Hades12

I thought the Water seal groves were in the wrong place for you to make a 4 port out of a 2nd gen engine.

RotorMotorDriver

iTrader: (1)

Could be, I hadnt researched it myself, I was thinking of using an -SE engine when I was researching it. I guess I got a head of myself talking about it, thanks for the correction.

~T.J.

diabolical1

iTrader: (3)

you can make a 1986+ 4-port by using T2 front and rear side housings.

Bluem

do the 2nd gen engines have a direct ignition system or a distributio?

diabolical1

iTrader: (3)

direct ignition with crank angle sensor

diabolical1

iTrader: (3)

i also forgot to mention another option. the poor-man's (pronounced: ghe-tto ) 4-port: siamese the 5th and 6th ports on a 6-port motor.

Bluem

so a series 4 13b and put 12a side plates and use series 5 n/a rotors 9.7 comp and counter weights, anything else to make it work?

diabolical1

iTrader: (3)

no ...

you have to 1986+ housings together, they cannot be mixed with anything older.

RotorMotorDriver

iTrader: (1)

So, lets break it down, either 84-85 13B housings, and 79-85 plates, OR 86+ 13B housings and 86+ turbo plates (turbo engines were 4 ports). Use the appropriate 13B rotors for the housings. Port matching shouldnt be a big deal since I personally would port it while it was apart, meaning you already have the tools to do anything else you might need to do for the manifolds.

~T.J.

Bluem

so a series 4 13B 6-port with turbo II side plates, what do i do for the ignition (distributor) can i use an earlier 13b or 12a front cover? so i can run a distributor?

steve84GS TII

You can drop a 1st gen distributor into the FC front cover or run a 1st gen cover,it all depends on your motor mount situation.

RotorMotorDriver

iTrader: (1)

Ah yes, thats the one thing we didnt touch on. Depending on how you need to mount the engine, the 2nd gen covers dont have the 4 bolt holes on the front for the crossmember, they mount differently than our 1st gens, so as Steve said, how you need to mount it will determine the front cover you need. Or, you could always put the 1st gen cover on and that way be able to go either way I would think.

~T.J.

Bluem

4 holes is what i need , so any cover from a 1st gen will fit?

Elysian

i'd get a S4 or S5 block and keep it 6 port... i'm loving my 6 port street port right now... its so beefy. its definately beefier than my 4 port street ported 13B that was in my repu running the same carb... repu was a bit heavier, but it did have the benefit of 4.62:1 rear end gears and a rx7 transmission...