Old-Timey GC 626 Receives 2nd-Gen. MX6 V6 and Suspension - Build Thread

This build thread will be about installing the Mazda KL series V6 and most of the suspension from a 2nd-generation ('93-'97) MX-6 into a GC-body ('83-'87) 626 coupe.

Here's the lucky 626. It is a bit rough around the edges but they are hard to find so beggars can't be choosers. I'll be fixing some rust in this thread and sprucing it up:

The factory turbo badges on these look like something you'd buy from AutoZone.

Here's my plan / What I know:

-Mazda used the same control arm ball joint from '83 through '97 so MX-6 spindles and brakes should go right on. This will make the car use 5-lug wheels and get rid of the silly GC captured front brake rotor (the bearing has to be pressed out of the hub to change rotors).

-MX-6 struts bolt into the shock towers no problem, same mount bolt pattern. Ride height is unknown. I'm hoping I'll be able to use them because it will give me a lot more strut brand choices.

-I plan to use GC axle shafts with MX-6 ends because the spline count is different between the two cars. I am hoping that the MX-6 spindles don't change the track enough to make my hybrid axle idea a no-go. I don't think that there should be a problem because the wheel offsets are nearly identical between the two cars.

-The GC 626 GT and the 2nd-gen. MX-6 use the same series transmission innards but the cases are very different. Fortunately, the rear mount area is identical in all ways that matter, so the GC rear mount bolts right on to the MX-6 transmission. This will locate the drive train in space so I can build the rest of the mounts:

-The MX-6 doesn't have a speedo cable, it has a sensor. But the GC does have a cable...So that was worrying me. But once I got the parts in front of me I was excited to find that the GC speedo cable drive drops right into the MX-6 transmission no problem.

-Due to the increase in cylinder count, the tach signal will have to be modified with one of those aftermarket signal converters. I am going to use the 80s-tastic stock GC digital cluster:

This thread will probably move slow due to family obligations and slothfulness, but hopefully some of you will find this project interesting as it moves along.

-James

Cool looking project...looking forward to updates!

I'm test fitting some stuff on my other GC 626, a sedan.

In this picture I have a GC strut mount and control arm, with the 2nd-gen. MX-6 mount bearing, upper seat, spring, strut, and spindle. Everything bolts together like it was meant to be. The GC outer tie rod end goes into the MX6 spindle correctly.

Very cool project! I don't think I've ever seen one of these cars, it's sweet! What turbo motor is it? F2T? Good luck!

These were pre F2T IIRC....

Yes, these came with a 2.0 motor called the FET. The 2.2 F2T was its descendant. The FET block is very similar to the F2T but has a shorter deck height, a different water pump design, and a different transmission bolt pattern. Also, the FET has an 8-valve head instead of the F2T's 12-valve. If someone was so inclined, he could de-stroke an F2/F2T using the FE/FET crank.

OK, I'm still using my '87 sedan to mock things up since it already has the drive train removed. The white coupe hasn't been touched yet. My plan is to get the drive train and suspension physically bolted into the sedan the way I intend it to be, and then I will tear apart the coupe and transfer everything over.

So, will it fit?

Yes, it fits.

You can't see it, but in this picture the rear transmission mount (The GC one shown above) is bolted to the subframe in the stock location, locating the drivetrain in space.

There is a little bit of interference between the oil pan and the passenger side subframe rail, so the pan will have to be modified slightly.

It looks like there is plenty of room around the motor for everything that needs to be there.

After I clearance the pan, I will begin building the three motor mount brackets that don't exist yet.

I'm never surprised when I see mazdas being franken'd together, you can carry/swap so many things from other gens or platforms its crazy! Lean manufacturing ftw.

paging swank...swank, please pick up a white courtesy phone

Swank has been involved. I believe i was the one that pointed him to the fact that he probably wouldn't have to do anything special for the speedo sensor in a previous thread.

That motor you see also came from me.

Thanks S. F. One. Sorry for not giving you a "shout out."

More pictures... I'm trying to document everything in case some other weirdo wants to try this some day. I'm probably the only one though.

This embarrassingly dirty picture is showing that the stock GC shift linkage bolts right up to the KL-MX6 transmission using the stock hardware. This is another place where you don't have to do anything except put it together.

This picture is showing that on the passenger side, the overall lengths of the half-shaft plus the intermediate shaft, for both cars, is THE SAME. So the passenger side is taken care of here.

Now, on the driver's side, there is some work to be done. The MX6 half-shaft is a bit longer than the GC one. So I am hoping (fingers crossed) that I will be able to simply combine the GC shaft portion with the MX6 outer joint bits to make a hybrid shaft of the correct length. This should work as long as they used the same CV joint geometry for both cars. We'll see....

JamesMcD wrote: Thanks S. F. One. Sorry for not giving you a "shout out."

Hah! Wasnt worried about it! I'm watching this one closely! Was thinking about doing a KL in a GD before I had a bad experience.

Cool build!

Are those foglights in the grille a factory thing or is that a owner mod?

The fog light grille is an aftermarket thing; it has Hella lights in it. I have another one for the white car too.

Everything in this update is for practice and will be thrown away!

As mentioned above, I have to clearance the oil pan to get the engine to sit low enough and clear the sub-frame. I can't use the oil pan on this engine because it has rust-through. But that's OK, I'm not actually using this engine in the end, so I can use this oil pan for practice!

Rusty oil pan:

With the engine in position, I roughly marked out the unwanted material with a paint marker:

Used up a pile of dremel cut-off discs:

Made a "patch":

Then, using flux core wire, which meant that the gauge of metal was really too thin for the process, I unattractively welded it in:

After doing that, I put the engine back in and found that I should have clearanced it just a bit more, so it's a good thing this was my practice run.

JamesMcD wrote: The fog light grille is an aftermarket thing; it has Hella lights in it. I have another one for the white car too.

That's actually pretty cool. You don't see stuff like that anymore.

If I don't post an update to this build within a month, will a bunch of you guys please ridicule and berate me via PMs? I would appreciate it. Thanks.

I could do that. But you're going to have to remind me.

Setting an alarm....now

I love that a lot of Mazda stuff is interchangeable. While I'm working on my MX-3, my SO is working on an absolutely mint 323 that we found on Kijiji and couldn't pass up. Since we're removing so many of the parts and hardware, we're noticing that a lot of them are identical, from seat rails, to drl brackets to knuckles.

Cool project. It's great seeing all the Mazda love here.

The awakening for Mazda projects has begun (yours, Lesley's, Dan's, mine) plus the more regularly updated ones from Dave, Skervy and ¯_(ツ)_/¯)
Where for art thou, Sir Swankypants?