Ok so I have a 82' with a S5 block waiting to go in, and is what I am wanting to do is as little swapping as possible.

A 12 front cover will work on the 13b right? So that will take care of mounting her... but will I be able to keep the FB trans? Can it handle the extra power of the 13b?

Also putting the 13b in, and mounting with the 12a front cover will that move everything back in the engine bay? I hope you understand what I am asking there lol Also if I have the S5 trans will that change the shiftier position?


Thanks for the time guys.

 

Oh man, I hate to say this but SEARCH NOOB! All your questions have been answered many times. I'd tell you the answers myself but it's long, involved and requires lots of typing.

Look in the 1st gen section. I have done several 13Bs in FBs. Mine even has an S5 NA trans modded to fit the shifter position. It's a different approach than you think.

Maybe when I have more time and feel like typing... maybe I could answer all your questions here in this thread. Give me a few minutes (hours).

 

Ok I have some time to give you a quick list of pointers.

You will need:
•a 12A front cover (as you already know)
•GSL-SE oil pan. These can be bought new from Mazdatrix for 90 something, or you can find them used for a bit cheaper
•RB front mount bar - this lets you install a 13B, which is a 20mm longer engine, in a 12A chassis. Your idea of moving everything back isn't gonna fly. Well, you could do it, but by the time you paid to have the driveshaft shortened, and redid the shifter position, along with the trans mount etc, you'd spend more money and more time than needed. Plus nobody would want it in the future. I certainly wouldn't - it would be a hack job in my perception. It's better to do the sensible thing and get a front mount bar. Heck it's similar to the GSL-SE factory setup and there is a radiator and clutch fan combo that works. But I understand your position.
•yes you an keep the FB trans. Lots of noobs ask this question. The bellhousing bolt pattern has been the same since 1974. And yes it can handle the power. Some people get away with lots more power than your S5 can make. But then if you drive like an idiot even a 12A can break them.
•The S5 trans can be used, if it's the NA one. A turbo trans is different and I've never installed one of those. As for the NA, it is easy to swap tailhousings to the FB type to keep the trans mount and shifter position correct for the FB. The swap procedure is covered in a thread in the 1st gen section somewhere.

Some other things that help the swap perform better are stiff motor mounts and a new trans mount. I prefer the competition version of both (from RB). They say thay're 40% stiffer than stock. Perfect. Don't mess with solid mounts because they suck and can rattle bolts loose. Another option is hockey pucks. But make sure your stock trans mount is ok at least. Most of them have sagged with rubber seperated from steel by now. So get something new if you do.

You will also need a 13B exhaust manifold or header. I'm sure this is obvious, but you didn't mention it. Do you already have something that will fit? The 13B stud spacing is 13cm, and 12A is 12cm. The more you know.

 

Thank you Jeff its a bit noobing, but its nice to just be told flat out you need A B C you know.

Are the synchros on the FB the same as in the FC? I have the NA S5 trans that came with the motor. The synchros are going out on the Fb trans for 1st and 3rd, and I was hoping I could scavenge off the FC...

 

Also what about the clutch and flywheel? do I use the one off the FB, or can I use the one on the 13b?

 

Trans: use the S5 trans with the FB tailhousing and shifter swapped over. Done. You must search for the procedure. The speedo drive gear and maybe the reverse light switch need to be swapped too.

The flywheel will obviously have to be the one that matches the engine. So the 13B one.

Since you failed to mention the year of the 12A that's coming out, I don't know whether you had a 215mm or 225mm clutch setup. If 225mm, the parts will swap onto the S5 flywheel. If 215mm, you will need a new pressure plate.

How can you tell? Metric tape measure across the diameter. Also the 225mm pressure plate has a massive step height compared with the 215mm.

There is another way to tell, assuming your setup wasn't molested previously; the year. All 82 and older are 215mm. All 83 and later are 225mm.

Your call on the disc, but if 215mm, it will have a 5mm underhang on the friction surface. It's been done, though. But best to go with a new 225mm disc. Stock duty. No need for HD or puck because you're at stock power levels and probably have never busted a disc before. Am I right? Again don't drive like a retard and it will last for years and be way more pleasant to drive than a solid disc.

 

Thank you vary much for the time Jeff.

 

Few more thing as I am looking at them... I am using the RB "Sidedraft Carburetor Upper Manifold Section 13B 6-Port" that lets you use the stock lower manifold. Have a Webber 45 for the set up.

The Air Control Valve do I pull it off, and make a block off plate, or is that a bad idea?

Also I pulled out the 6-Port Sleeve's (my thinking I don't need them because I am going to pin them open anyway) My main reason for doing this is...

It is locked solid...

The crank angle sensor drive gear I am guessing is the same from 13b to 12a?

Premixing works the same right? Cap off the MOP and done?

Brake booster vacuum line where will that go now?

And lastly as I am thinking about it, there are spots for injectors and what not on the block, I cap all of them off right?

I really wish there was a photo by photo instruction book on this. I stress, and worry about stuff not going together right, or not being able to get back to gather... you know the "I have never done this oh god oh god what if."

 

Sorry about the broken link

 

I'd say one of the nice things about keeping the stock LIM is you can keep the aux port actuators active and benefit from the better low RPM performance. But you decided against it.

I personally will try a similar setup at some point. The engine just needs to be built and a set of 38mm venturis or "chokes" I guess is what they're called needs to be purchased for the weber 45DCOE. Then I can throw on my recently purchased RB upper manifold for S4/S5 and see how well it works with functioning aux ports.

Let's see.. more noob questions to answer... You know, you should have posted in the 1st gen section. Lots more perople with knowledge could have chimed in by now. But I'll see what I can do.

Get an ACV cover plate (or block off plate) from RB or make your own. You might also look into filling the ports in the side plates with quicksteel. I did this on the Luna engine. It keeps the manifold cool for greater performance - especially for a carb. Otherwise you have hot exhaust heating the manifold and the carb. Note once the ACV ports are filled in the side plates, you might not even need an ACV cover plate. I can't remember whether there is any communication between the aux port circuit and the ACV stuff. Oh right you're not using aux ports...

Sleeves with a ramp shape flow somewhat better than a gaping 90 degree straight hole in the side plates. I don't trust pineapple inserts so I'd go with atkins aux sleeves.

Same drive gear. Look into DLIDFIS for your ignition as well. But start out with stock FB ignition since, well, since you're new.

Uhg, why do you want to premix? It gets stupid after a while. Ask PercentSevenC how much he loved doing the premix song and dance every time. Then again does the weber even have OMP nipples? By the way the 12A OMP CAN NOT be fed into the OMP fittings on the rotor housings. It blows the seal every time. As for the fittings in the LIM, um, probably the same thing will happen due to the tiny orifice. I'd personally drill them out to the same size as was used in the Nikki. I'd choose the LIM oil injectors for this as they're removable. Not so sure about the little brass jets in the rotor housings. I wouldn't want ruin those.

There is a brake booster fitting on the LIM. Use that. Did yours come with one? I hope it did. If not, I'm sure some around here has a spare. I might even.

There is a fifty dollar block off kit from Mazdatrix and Racing Beat that blocks the injector holes in an S4 and other years. It's for FC and older. Then there's another kit for FD and Cosmo. Obviously you know which kit to get, right?

It's interesting that you stress about stuff like this. I live for this kind of stuff. The things that make me stress are tuning a megasquirt. It just doesn't compute (yet). I'd gladly chose an FC 13B with carb swap into an FB over a megasquirt any day. It's cathartic for me. Really, it's like therapy (I'm guessing). I bet that's why I've chosen to spend what little time I have on the forum these days to help you out - because it's what I'd rather be doing myself. Or something like that.

 

Ok made a ACV cover plate

The one on the FB right now is not stock, idk don't have any make or anything on it.

I am doing the premix song, and dance already. Idk I like it...

You are right about the LIM booster fitting, I was looking at it wrong. There is a similar fitting on the rear housing whats that for?

I wish I had a fifty dollars for a block off kit haha I will come up with something for it though.

Thank you Jeff for all the help and I am sorry its taken so long to get back.

I stress about stuff I have not done before, I dont even want to know how stressed a megasquirt be haha

 

Thanks for the update.

Ok, you're going to have a really hot manifold until you fill in the ACV ports in the engine. But don't take my word for it. Once you get it up and running, feel the manifold after it jas idled foor a bit. It will feel pretty hot with no explecation. Even an exhaust heat shield won't help. The only thing that helps is to fill the ACV ports in the side plates with quicksteel or something similar.

The other fitting will have coolant flowing out of it. Block it off with a 3/8" hose and a 10mm or 3/8" bolt or stud that has an unthreaded section.

 

Put a set of FC seats in her, feels awesome!

Ok rear hatch switch is not working... keep blowing the fuse. Driving me crazy! But oh well there's go to be a short some place.

Fill in the ACV ports on the port side? Well that's what a tube of red RTV is for! haha Just kidding.

What is the best way to get the front cover off? Do I need take the water pump off too, and a puller to get the pulley off?

 

You're in luck. Rotaries don't require a puller like boingers do. Consider this logically: Is the waterpump in the way of the direction the front cover must go in order to remove it? You have an eccentric shaft and a stack of parts on it like a counterweight, a dizzy drive gear, an oil pump drive sprocket etc. So the front cover can't just go down one you remove all the bolts. Heck you can't even access all the bolts unless the waterpump is removed. Or rather I've never tried it because it's like taking off socks when your shoes are still on.

The front pulley hub has a 19mm bolt. Search the forum for ways of how to loosen the bolt. I use an impact (1/2" drive) and usually lock the flywheel or the rear counterweight. The front bolt can be tough to remove if the previous owner did something stupid. But heat from a mapp torch always works if the bolt is stubborn. Otherwise a factory installed bolt spins off after a few seconds with the impact wrench.