warwickben

iTrader: (1)

hi guys i chosen to start to get all the parts i need to do my motor swap, i decid iam going to put a turbo motor from a second gen but carb it to make it a little easyer for me and my buddy to work on and in stall. so may say it will be harder but i have decied to go this way.

i seached and could not find a answer for this. i know to put a t2 motor in to a sa you need to use a front cover from a frist gen. would i be able to the front cover and water pump from my 12a.the reason i ask is i heard of people swaping out 12a rotor houseing and rotars for 13b. i think i rember reading i could, my compture crashed so i lost all the links i saved with all the info, i figured if i can it would save me some money ect and i wouldnt have to worry to much about the omp. if i cant use the front cover from my 12a what front cover do i need to use,is it a glse? and how would i go about getting one and the omp ect.

ill say sorry a head of time cause i know ill be told to seach but i did and couldnt find the answer i was looking for.

steve84GS TII

You have a few options depending on how you progress with the swap.

1.You can use a 12A front cover with the 12A OMP,but you will only be able to hook up the 2 oil injectors on the rotor housings since the 12A OMP is a 2 hose unit.That isnt a problem,it will be enough and since your going to run a carb,you wont be using the TII lower intake with the remaining 2 oil injectors.If your going to turbo and carb the engine,then some premix would be a good idea to supplement the 12A OMP's output.
2.If you run only premix,then you can run any 1st gen front cover and block off the OMP and injectors.
3.If you run the 13BT fuel injection and intake manifolds,then a GSL-SE front cover will allow the use of the 4 hose S4 TII OMP and all 4 oil injectors.

Regardless of the setup you choose,you will need the GSL-SE oilpan.


12A/13B rotor housing and side housing swapping only applies to 12A and GSL-SE 13B engines.All engines from the 2nd gen on up will not swap housings since the water seal grooves moved from the rotor housings to the irons.

warwickben

iTrader: (1)

thank you so much for that answer, iam going to keep it turbo othere wise i would just stay with a 12a and build it all motor.

you said i should still premix it if i decied to turbo the motor and use the 12a front cover and omp, would i still use the same amount of premix if i was not useing the omp. the reason i ask is cause in the FAQ section the go into detail on how much premix to use when just running premix.

trochoid

iTrader: (6)

Standard pre-mix only ratio is usually 1 oz/gal fuel. If your retain the 12A mop, 1/2oz,/gal fuel will be more than sufficient. If you use the SE front cover, no extra pre-mix is needed and even using the 12A front cover, pre-mix is not required but can add a margin of safety.

mikewoodkozar

Dont forget that you will also need a GSL-SE oil pan for the swap

steve84GS TII

Mazda went back to 2 oil injectors after the S5, and with each series/generation they have steadily cut back on oil delivery.This is due to several factors including increased oil quality/capabilities over the years,better metals and running surfaces inside the engine,the need to reduce emissions and the need to reduce any maintenence requirements that are unique to the rotary so its easier for the average consumer to own one.

Having only 2 injectors doesnt garuanatee that the S6 engine and the 12A engine deliver the same amount of oil to the engine however.The 3rd gen is designed to work at much higher HP levels and it has the advantage of many more years of development.Its best to retain the oil delivery amounts that are appropriate for your series/year of engine.All 2nd gen engines have 4 oil injectors and an OMP that puts out the correct amount of oil.If you take a 2nd gen engine and install a 2 injector 1st gen OMP, then its best to play it safe and run a little premix to back up the OMP system, which is now only half of what the factory intended.This is especially true if you turbocharge since every part of the engine will be under greater stress and run at hotter temps when boosting.

warwickben

iTrader: (1)

so you guys agree that if i use my 12a front cover and oil pump use 1/2 oz to gallon of gas. i figure running the 12a omp and premix will be cheaper then just premix any ways. thanks again.

o yeah does it matter my car is a sa 1980 rx7?

steve84GS TII

That should be fine.
With the OMP working,youll also have a backup if you run out of the mix oil or forget to put it in.The output of the 12A OMP alone should be adequate for most driving conditions,especially if your N/A.

All 1st gens require about the same amount of work to convert to another type of rotary.There are minor differences,but nothing too difficult to overcome.

warwickben

iTrader: (1)

stupid thing i over looked, what are my options for knowing how fast iam going, i cant just run the speedo cable to my cluster right i knwo the gears are different.

RX3SP

iTrader: (62)

It is true that the 2nd gen oil metering pumps have 4 oil lines and the n/a 12a pumps have 2 oil lines, but it's a common misconception that the 12a pumps flow less that the 87-88 TII pumps. A good 12a pump will flow at least 1cc/min(usually 1.1-1.3 in my experience for the early pumps) at 2k engine rpm with the arm on the pump held in the wide open position which is well within the 1.01-1.32cc/min specs on the TII pump tested in the same manner.

warwickben

iTrader: (1)

that makes me feel better knowing that.

steve84GS TII

Speedo cable hooks right up......did for me anyways.

warwickben

iTrader: (1)

how off will it be?

i figured since it has different gear's it would be off.

RX3SP

iTrader: (62)

Your speedo won't be off by much. Your 80 came with a 3.909:1 and the TII had a 4.10:1 differential ratio. You'll have approx 5% error. The speedo will show that you are going slower than you really are. Of course, if you are running a non stock tire diameter it will also have an effect.

warwickben

iTrader: (1)

thank you and for being nice .

Vashner

Find one of those radar stations that show you how fast your going after it's running.

warwickben

iTrader: (1)

thats funny that you said that. my car is a 1980 so it only read to 85, it was off by 5mph at every speed. i then installed a 1979 cluster that read past 120 mph. and its dead on.