Hey everyone I am now the proud owner of an 85 GSL . The car has a seized 12a motor in it that is going to be coming out. I plan on putting in my friends 13b motor. I have read a lot up on it and I pretty much know what im doing. The only question I have is..... What kind of flywheel,starter, and clutch do it use?Should I run a 12a starter, flywheel, and clutch or a 13B. Im going to be running a 13b motor but a 12a trans. Please Help Guys!!!!

 

I would use the flywheel that comes with the 13b motor. If you are going to go with a light weight one just make sure you get the counter weight to match the rotors that you have in the motor.

Clutch, transmission and starter are the same.

 

Alright awesome man thank you so much! Also im a little confused because I am getting mixed info from people. So I can use a front cover from a GSL-SE and I also need a oil pan from a GSL-SE?

 

Let's start that the beginning.

You have a 12a FB right now.

And you have a 13b engine you want to put in.



Where did the 13B come from? FB? FC? Turbo 4 port? NA 6 port? Carbed? Each way requires a little bit differnet.

 

Which 13b motor will you be installing?

As for starter, flywheel and clutch, it depends on a couple of things. You always want to use a starter, clutch and flywheel that matches the gearbox you are using (in this case, 12a). However, with regards to the flywheel, that rule is only applicable if you have an auto counterweight with aftermarket flywheel.

If you will be using a mazda flywheel with integral counterweight, then the flywheel MUST match the rotating assembly of the motor. Otherwise you will encounter balance issues.

If you are using an early 13b such as rx4 or cosmo rx5, then you can use the factory 13b flywheel and it will fit your 12a gearbox with 12a starter and clutch.
If you use a later turbo 13b engine, you will need to install an auto counterweight and billet flywheel to suit the 12a gearbox. The auto counterweight HAS to match the rotating assembly.

Hope that helps.

 

The motor is out of an FC and it is non turbo. I also have 2 n/a fc transmissions as well. Would i be better off installing that? And if so dont you need to change something so that the shift fits? The car is an 85 GS

 

Are you using the FC fuel injection?

For fitmet you'll need to use a 12a or gsl-se front cover (for the engine mount cross member) and a GSL-SE oil pan.

If you use the 12a front cover, you'd be best to go carbed for the 2 line OMP. If you are going FI, you'll want the GSL-SE front cover so you can fit the 13b 4 line OMP.

Not 100% on the trans. You can use the one that's in the car. Flywheel native to the engine, and clutch native to the trans. Starters all interchange (FC starters use a through bolt with a nut, FB starters have a threaded bit on the starter. Easily interchangable.)

 

I definitely am planning on fuel injection. Im going to mount an external fuel pump somewhere. And I already have a GSL-SE front cover with OMP. Im just confused about the trans now. Should I run my 12a trans or should I run a N/A FC trans?

 

I'd run the FC trans. If a TII is easy to swap in, that should be as easy or easier. Test fit it!

Your car already has an external fuel pump. Install a walbro as the 12a carb pump is low pressure, and you're good to go.

Get a GSL-SE fuel tank or mod your 12a tank for a baffle setup or you'll go lean running the pump dry on hard turns with lower fuel levels.