J-spec nitrided R5 4 port 13B, streetported
rejetted Hitachi carb
channeled manifold
light steel flywheel, 225mm clutch
'78 close ratio 5 speed ribcase

Test fitting engine and tranny.



It's a work in progress (like all of them).

 

nice

 

SWEETUH!!! I'd love to pick up an old RWD GLC. Those things share a bunch of RX-3 parts too!

Good luck man!!!

-Vince

 

Don't think of it as modification. Think of it as restoring it to the way Mazda should have built it.

 

That looks like fun.

 

About time Jeff! You've had that for awhile!!!!!!!

 

Jeff, looks good so far... Congratulations.

Do you know what the weight difference is between the GLC and the Starlet?...

Dwayne

 

....I want one!!!

 

looking good


really?

 

They share some parts. I had to modify the front cover motor mount plate to raise it up about an inch. I raised the tranny mount up a bit too. Now there's some finger room between the pan and the main crossmember. The carb also seems to sit level now. That's always a good sign.

A local rotary shop installed a hydraulic clutch master and slave (they modded the pedal assembly and some other things). They also installed 1st gen RX-7 struts and the vented rotors. A nice touch. The struts lower the front end two inches so I must be careful when I fab the exhaust. Details will come after I've done more work.

What have I done so far, you ask? It has a 16 gallon fuel cell with modded sender to work with the stock Mazda guage, and a 3/8" hardline running to the front. The stockers were a 9 gallon tank and 1/4" hardlines. Too small. Being a piston car, the fuel lines are on the same side as the exhaust on a rotary. Not good. I ran the new send line away from exhaust heat.

 

The engine


Tranny


Modified mounts


1st gen starter, '78 carb, channeled '74-'75 manifold, carb spacer


Center section and header

 

Nice work, looks to be coming along.

 

The engine and things are back in. Pics to follow.

 

The engine with just the slave cylinder installed.


Exhaust after high temp paint and header wrap.


Header installed.


Slightly modified 1st gen 3 core rad and oil cooler


Both installed. Sorry about the blurry picture. I ain't no photographist.

 

We got a lot done today. Installed manifold, carb, alt, belt, fan (blades shortened a little to clear the hood and upper rad hose), ignition coils, front grill. Connected battery cables and tested the starter. Hooked up ignition relay and float bowl breather on the carb; created a wiring harness for alt wires, DLIDFIS signal wires and trailing ignitor with condensor wires. Filed down two quick disconnectes for DLIDFIS and started on a heat sink for a couple of GM HEI ignition modules. Oh, and I hooked up the reverse light switch, filled the tranny with oil and installed the shifter.

I can't say when it will run, but the time draws ever closer.

 

Jeff -

When I built my GLC in 1987, I knew it would not get 30 mpg any more. I searched around for a nice, rectangular tank that would fit where the spare tire well is, and I installed a 17 gallon tank from an Astro van. It has an immersed fuel pump, and I had to regulate it down to the correct pressure. I drove it over 100k miles, sold it and later it was wrecked. I ended up with the salvage, and I have kept the fuel tank. If you are interested, let me know.

I also used a 13b with an RX-4 tranny, and I built a rear axle for an RX-7 limited slip. I thought the 2 1/4 inch lowering with the 1st gen struts was too radical, so I installed two or three of the RX-4 strut spacers at the top of each strut. That just barely made room for some decent tires.

I cannot remember if the housing center section was from a RX-2 or RX-3, but one of them uses the same diff as a small axle RX-7, and is the same width and same diameter where the axle tubes are welded on. I assume you will know from the photos.

 

Was your GLC the one with the Holley and could go too fast for the tires? I've heard stories. By the way, I ended up with the MG Midget.

Thanks for the offer of the gas tank but it already has a 16 gallon fuel cell from Summit with a GM guage sender which I rewired to send a more appropriate impedance 'signal' for the stock Mazda guage. The external pump is noisy but it's a temporary Facet type which will be replaced with a Carter mounted to the frame rail with rubber 'things' to dampen noise.

This '78 close ratio tranny came out of an RX-4. It has the close ratio 1st to 3rd and a tall 5th.

I think the GLC has 3.727 diff gearing. Did yours at first? What ring and pinion did you eventually go with? What would you recommend for a close ratio tranny and a large streetport? Considering the lightness of the car, I'm thinking 3.9 or 4.1.

 

For those who may've been wondering about filing down some quick disconnects for use in the dizzy connector, here you go. Notice they're opposite? They don't have to be perfect, as you can see. Just check for fit often and when they fit snug, you're done.



A couple of GM HEI ignition modules on an aluminum heat sink (sheet aluminum). The signal wire runs up behind, seperates to two wires connecting the G and W terminals in parallel. I don't remember which goes where, but I believe G is red and W is green, or in other words if compared to a J-109, G+=red and S-=green. We'll see. If I'm wrong it's easy to cut the signal wires somewhere in the middle, flip and reconnect with a couple butt connectors. It doesn't have to be a high tech solution.



Here's a view of the oil cooler lines, trailing coil, scizzor jack etc.



Crimp the filed down quick disconnects onto the signal wires, in this case some speaker wire I had laying around, push them in, bend them up and join with the harness.



The interior is almost done.

 

wow its comming together quite nicely. i like the direct fire ignition you set up.
i still have to figure out how to wire mine.
good luck with the car!

 

Thankyou.

The wiring is pretty strait forward. Good luck with it.

Hey guess what? We fired it up briefly last night. I sprayed some starting fluid down the carb and cranked it. It fired right up and died a second or two later. Progress. There is a short video of the event but I can't post it. Maybe PercentsevenC will later today.

I gotta hurry and toss the carpet etc back in and get this thing out of the garage for test driving.

 

Jeff,
I still got that GLC/RX7 hybrid LSD rearend in my shed........
Shes just crying to be slipped under that little terror!

I had a guy who wanted it,but he hasent contacted me in a week.When I get back into town next week,if I havent heard from him.......100 bucks plus shipping.....you know you want it!!

 

I've spent a lot to get it this far. That's an awesome deal though. In a week you say? I should have an answer for you by then or sooner.

 

"I think the GLC has 3.727 diff gearing. Did yours at first? What ring and pinion did you eventually go with? What would you recommend for a close ratio tranny and a large streetport? Considering the lightness of the car, I'm thinking 3.9 or 4.1."

Jeff - My GLC was intended as a daily driver. Ken tried to talk me into a street port and a Holley, but I just wanted a stock motor. I think I made the right choice, as it ran 100+k miles for me, over 40K for the next guy, and then they put it in a REPU and I lost track of it. Ken built the motor using a worn out Cosmo engine plus some nitrided cast irons from an 82 RX-7. It was totally reliable. Of course I would build it today with my usual stock primaries and street ported secondaries, which seems to work really well for a daily driver.

The diff I used was a stock 1st gen 3.9, don't think I ever drove it with the GLC diff. We found a driveshaft that bolted right in, can't remember what model it was from. It was perfect for what I wanted, and for street driving, I would not change it even with porting. I realize you probably aren't planning to run yours 100,000 miles!

Can't tell what you are doing, but I used a Cosmo radiator, which required cutting the core support and slipping it forward. The filler neck protruded aft, worked out well. I still have a couple of good Cosmo radiators, if anyone needs one. I certainly never had any cooling problems.

I have never used an electric fan. Even my Ford 5.0 in the 84 has a stock RX-7 fan, no viscous clutch, although I made a larger pulley to slow it down. I tried a couple of aftermarket fans, and they just would not work on a hot day. The only problem was sitting at idle in traffic, never had a cooling problem when it is moving.

My GLC was a 1980 Sport, so it had good instrumentation. I pulled the upholstery from the seats and adapted the velour fabric and padding from some Audi 4000 seats, including the rear. A lot of work, but it looked very nice when it was finished.

With the big struts and brakes, heavier rear axle, bigger radiator, and stock cast iron manifold on the 13B, it weighed just about 150 pounds less than a stock 1st gen RX-7. But it handled quite well and was a fun drive. I surprised a lot of people out there on the freeway, especially the guys with the German cars who always thought they could just blow me off!

 

It runs and drives! A little loud at first but then we installed the carpet and it's actually quite pleasant inside now. It's still loud out the back.

For being a large streetport it actually has some low end. Probably helped by the light steel flywheel and the car's rather low weight. Just driving it, it feels ten times lighter than the REPU and even lighter than the baja. Of course the baja has a stock 1600 with a lot of hard miles (blowby, kinda gutless). All the GLC needs now are some Racing Beat springs, another hood latch (the cable popped off and I had to reach all the way up from under the car - not fun) and the rear brakes need to be adjusted. The 3.727, or whatever it is, is not that bad with the close ratio tranny. The two seem to go together, but I'm sure a 3.9 would feel better.

This car also has one of those stock driveshafts that just bolts right in. I didn't know what it came from, but it has tiny u-joints and a large diameter tube. Exactly opposite of an RX-7 shaft which has larger u-joints and a smaller diameter tube. I'd think the smaller diameter tube would have less rotating weight and accelerate faster. I think if I took the stock shaft and an RX-7 shaft, which happens to be too short, to a drive shaft shop and had them lengthen the RX-7 shaft, that would be the way to go.

I used an aftermarket replacement '79-'82 short style 3 row radiator and cut the side mounting tabs off. I didn't want to cut the front of the car all up so I trimmed as little as possible while still allowing adequate strength and air flow. I think it worked out ok. I also cut off one side of the oil cooler mount and supported it from beneath. I also had the option of using a beehive oil cooler instead but the air oil cooler was available and they usually tend to work better.

This car wanted to overheat with the other 13B and the beehive, which turned out to be caused by a faulty stant thermostat which would not open more than 1/4. The electric fan also wasn't pulling enough air. This time I installed a gutted thermostat and a trimmed stock fan. I had to trim it to clear the upper radiator hose and the hood. I went a little overboard and trimmed about an inch but the engine now runs at a balmy 140-150° with the oil cooler in front of the radiator. The heater blows warm air so this solution seems to be working. It doesn't want to overheat when it sits there anymore. This is especially great because the engine is a fresh rebuild with only about 2 hours run time, and rebuilds always tend to run hotter than well seasoned engines.

The filler cap is on top of the radiator so it's kind of a trick to remove it and fill the radiator with the hood on, but if you do it once, it's not a problem after that.

Speaking of the stock cast iron manifold, I have one of those. It came from a J-spec nitrided R5 13B. It had perfect dimensions to fit the engine bay. We went with a header instead and the manifold will go on my REPU.

 

Here are a couple of vids we took.

Firing it briefly on starting fluid on Saturday

Starting it up for real yesterday