1975 Mazda REPU - Build and Repair thread

chuyler1

goes to eleven
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2013 CX-9
Working on installing the Atkins pulley kit.



Had to grind off this rivet on the original pulley.



Got the water pump and crank pulleys on. Side mount installed. Also mounted the new Spal 16" electric fan. However the alternator I bought won't work with the side mount kit so I'm going to get an FD alternator instead.



 
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'86 RX-7 Base, '79 RX-7 GS
Nice! I wasn't aware Atkins made a kit like that. Is there any advantage other than being able to use a 6-groove belt? Also, I'd try to come up with some kind of duct for that fan. There's a lot of uncovered area that's not going to be getting any airflow.
 

chuyler1

goes to eleven
Moderator
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2013 CX-9
It should be fine. I've seen numerous other rotary installs, some with smaller fans. It has a rubber gasket to ensure a proper seal. I'm going to watch temps and will make changes if necessary. I have the original shroud but there is no way to mount a fan to it securely since it is only designed to mate up to the crank driven fan.

I did a little more wiring tonight. Just tucking things in and making sure all the runs are the right length. I still have to install a ton of harness terminals but the fuse box is in, relays are in, and steering column is all hooked up.







 
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'86 RX-7 Base, '79 RX-7 GS
It should be fine. I've seen numerous other rotary installs, some with smaller fans. It has a rubber gasket to ensure a proper seal. I'm going to watch temps and will make changes if necessary. I have the original shroud but there is no way to mount a fan to it securely since it is only designed to mate up to the crank driven fan.
Since this isn't a "performance" build you'll probably be fine. You'll only be moving cooling air through approximately half of the radiator area. Even with the fan sealed to the radiator it's only going to move air through that circle with the truck stationary. It wouldn't be too hard to cut and bend some aluminum to make a slim shroud.
 

chuyler1

goes to eleven
Moderator
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2013 CX-9
I'll eventually upgrade the radiator and when I do, I'll have a shroud made to fit. Given the weather up here it's not going to be an issue. If I were in SoCal, it would be different.

Back to more wiring. The gauge cluster is finished and back in the truck. Some of the circuits were fried on the board but the gauges themselves were fine so I wired up the AAW harness direct to each gauge and added diodes where they were needed to get the warning lights to function as originally intended. For some of the lights, I replaced the twist-in bulb holders for pigtails so the power goes direct to the bulb. Tonight was the first time I got to test things in the truck. I still have lots to connect but I'm hearing the new relays click on and off so the end is near.





Also, the intake came in. I need some fabrication done before it will mount up...but at least it is here.





 

chuyler1

goes to eleven
Moderator
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2013 CX-9
Yeah...that's where that aussi company was supposed to come in. I need to get Lui up here to mock up a manifold so his fabricator can make one for me.
 
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'86 RX-7 Base, '79 RX-7 GS
I assume you're going to have one throttle body for each intake port. What is the diameter of the throttle bodies and are they staged in any way? I haven't seen too many people go with four individual units; most of us stick with two. In an ideal world you'd have one throttle body for each port but they'd need to be different sizes for the primaries and secondaries. What made you go this route versus using one of the off-the-shelf carb intake manifolds and a carb-styled throttle body?
 

chuyler1

goes to eleven
Moderator
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2013 CX-9
We're going to port the motor once we get it up and running, and since this is a 4 port block, not a 6 port, we don't have to worry about the auxiliary ports. They sell longer/shorter air horns if I need to fine tune primary vs secondary lengths. As seen in the video below, Xtreme has done a similar thing. I would have loved to just gotten this kit but as I mentioned above, they were giving me the run around since January. Whether I do a bridge port like this or just a street port is to be determined. I don't think I need a motor that makes all its power above 8,000 RPM in a truck....although it would be a hoot to drive.

As far as "why this route?", in short, "why not?". Just something different and unique. I didn't want turbo, so I figure we'll do a no-regrets N/A build.

 
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'86 RX-7 Base, '79 RX-7 GS
We're going to port the motor once we get it up and running, and since this is a 4 port block, not a 6 port, we don't have to worry about the auxiliary ports. They sell longer/shorter air horns if I need to fine tune primary vs secondary lengths. As seen in the video below, Xtreme has done a similar thing. I would have loved to just gotten this kit but as I mentioned above, they were giving me the run around since January.
I assume you mean this kit: http://www.xtremeautoparts.com.au/shop/pc/13B-Quad-Throttle-Kit-720p3252.htm. I thought they stopped selling aftermarket parts; it looks like they just changed up their site. My side-mount alternator kit is one of theirs. Typically length tunes the powerband and diameter is used to control airflow (mass flow/velocity = power) but you can use length to control airflow to an extent. I purposely looked for S4 RX7 turbo irons since the timing is the same for both primary and secondary ports. That way I could use four equal-length intake runners and just have two different pipe diameters after the throttle body. Your configuration definitely has more room for adjustability.

Whether I do a bridge port like this or just a street port is to be determined. I don't think I need a motor that makes all its power above 8,000 RPM in a truck....although it would be a hoot to drive.
If you want drive-ability I'd stay away from a bridgeport. With a 4-port block you can make good, usable power and torque with a large street-port. Defined Autoworks in Ohio made over 230 HP to the wheels with a street-ported, naturally-aspirated 13B-RE block (also had scalloped rotors though). I have that same porting on an earlier S4 turbo block and am hoping for something north of 200 HP.

As far as "why this route?", in short, "why not?". Just something different and unique. I didn't want turbo, so I figure we'll do a no-regrets N/A build.
I can sympathize. That's pretty much my motivation for the FC as well
 

chuyler1

goes to eleven
Moderator
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2013 CX-9
Yes, that was the kit. I made a deposit back in January expecting it in April. Gave up in August.

Our original plan was street port the intake, but don't touch the exhaust port, to provide more torque. Add longer intake horns maybe. That'll give more power, but still the ability to tow a trailer. At this point though, I just want to see what we get without porting and how it feels...then I'll decide whether I want max power, or just decent power and drivability.
 

chuyler1

goes to eleven
Moderator
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2013 CX-9


Knocked off some more wiring this evening.

1) main fuse with shunt for ammeter is in.
2) stereo amp is all hooked up except for speaker wires
3) gauge cluster is in
4) wiring harness for radio is done

Verified the following which was very exciting: Dash lights work with dimmer switch, I can hear low beam and high beam relays clicking on. Radio turns on and remembers presets. Ammeter works.

Heater 3-way switch does not work. The wiring is pretty beat up. I'm going to have to open it up and clean the contacts. Not looking forward to that because it means disconnecting all the cables and remembering how it all goes back together.
 

bazooka joe

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2016 Miata Club, 2014 CX5 Touring, Honda 1976 XL 175
Nice work! Take lots of pics!!! That's what I do now with everything I end up taking apart!
 

chuyler1

goes to eleven
Moderator
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2013 CX-9
Heater fan switch and controls restored with new harness and cleaned up contacts and stretched springs inside to make sure it will work like new.







 

chuyler1

goes to eleven
Moderator
:
2013 CX-9
Center console is in, checking off more circuits...





1) Radio is wired up and sending audio to the amplifier

2) Heater controls are wired up and functioning

3) All dash lights work with the dimmer

4) 12v acc works

5) Parking brake light works

6) harness for trailer brake controller is ready to go

7) Exhaust Overheat light is wired, but haven't tested the sensor, not even sure i will install it. I might use the light to display something from ECU instead.
 

chuyler1

goes to eleven
Moderator
:
2013 CX-9
Not much to show tonight but I did manage to connect the wipers and verify my relay work from months ago was done right. It's so exciting to see the wipers move and stop at the right spot!

I also connected the heater core and played around with the exhaust temp sensor. This little thing is supposed to be bolted to the passenger floor and set off a light in the dash if it gets too hot. Only problem, it takes a serious amount of heat to set it off. You'd smell your shoes burning before this thing alerted you. I got it to trigger outside the car, but I couldn't get it to trigger mounted to the floor...so I'm not going to bother hooking up the warning light.

 
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