Radiator Bracket Installation...
...upper / lower radiator brackets
...3/8x3/4x36" Hi density automotive grade foam tape
...pop rivit gun
...(2)1/8"x3/16" grip pop rivits
Install the lower bracket We make 2 different types of lower radiator brackets for the 1st gen RX-7...
...'79-'83 RX-7...The early cars use a bracket designed to slip-over existing tabs welded to the RX-7 chassis. These tabs measure about 1"x3", and are located on both sides just ahead of the sway bar.
...'83-'85 RX-7...The later cars all have additional oil cooler brackets attached to the chassis, located on both sides just in front of the sway bar. Our lower radiator bracket for these cars bolts directly to these existing mounting points.
...Part of the underbelly tray below the radiator should be removed between the steering rack and the bottom of the radiator. This modification more area for the hot air exiting the radiator to escape the engine compartment.
...radiator aluminum upper seal panel
...Drill & 1/8" drill bit
...2x2x36" low density foam seal material
...The foam material seals the area between the bottom of the radiator and the plastic underbelly tray. Sealing this area prevents cool air from bypassing under the radiator. Cut the foam seal material as needed to fit.
...Slip the radiator onto the installed lower radiator bracket (hi-density foam should prevent any metal to metal contact). Additional protection from metal-to-metal wear and contact can be had by using automotive grade silicone sealer. Apply the silicone adjacent to the foam strips for firmer "cast-in-place" rubber vibration protection.
...Place the upper aluminum radiator seal in position over the top/front of the radiator core (located by the existing holes at the front of the panel).
...secure the seal panel using existing holes. The upper bracket should be attached to the radiator's upper core brace w/ rivits using the holes in the back side of the upper bracket as a drilling/riviting template.
Radiator Hose Installation...
...upper hose (NAPA #7922)
...lower hose (NAPA #7286)
...(4) hose clamps
...Trim the hoses to length & install. Make sure that the lower hose has a spring type insert inside to prevent hose collapse at high RPMs.
NOTE:...If you want to use your stock RX-7 radiator, it will need to be re-located farther forward to a more vertical position. Some people have had success with the stock radiator by removing a pie shaped section from the sheetmetal the radiator bolts to, with the result of swinging the bottom of the radiator forward. Others have used radiators from different applications, using fabricated brackets. Even stock LT-1 Camaro radiators have been installed by denting in the sheetmetal “frame-rail” sections of the RX-7 to make some additional room. Whatever solution you decide on, if you live in one of the warmer climates such as Arizona or Florida, you will need to pay extra attention to directing every last bit of air drawn in by the fan THROUGH the radiator, instead of around it. This means sealing off all the paths above, below, and around the rad with sheetmetal, cardboard, or foam. REMEMBER...the RX-7 has a small engine compartment with minimal exit paths for the hot air to escape from. If the air can’t get out fast enough from the rear and bottom of the engine compartment, it will simply go around the rad or fan to the low pressure area in front, reducing the amount of fresh cool air drawn in. Our radiator kits use the largest possible radiator without requiring major modifications, and our radiator brackets are engineered to seal off the paths around the rad without further fabrication.
Thermostat...Be sure to use a new high quality thermostat that features a balanced design, such as the Robertshaw "extra performance" series. One almost necessary modification to your new thermostat is that a 1/8” diameter hole should be drilled thru the flat area of the disc to allow more thorough purging of any air bubbles when adding coolant. This mod also makes the process much faster, as the bubbles can now travel thru the closed thermostat into the upper radiator hose.
Heater core plumbing...The RX-7’s heater core should be plumbed in using a “restrictor” fitting. The reason is that the heater core can be a short circuit path around the radiator core for the water. In warm weather the heater is turned off, with no airflow through the core to cool the water flowing through it. The effect is that, without a restrictor fitting, a significant percentage of your coolant can circulate through your heater core instead of the radiator.
Water Pump... 2 large fittings on top for rad hoses, 1 smaller 5/8” fitting on upper passenger side, 1 smaller 3/4 fitting on lower
passenger side, 1 smaller 3/4” fitting on lower passenger side. They should be plumbed as follows...
...Passenger Side Large Upper (1-1/2”)... water in from bottom of radiator.
...Driver's Side Large Upper (1-1/2”)... water out to top of radiator.
...Upper Passenger Side Smaller(5/8”)... water out to heater core.
...Lower Passenger Side Smaller (3/4”)... water in from heater core.
...Lower Passenger Side Smaller (3/4”)... cap end of hose above head level. Use for bleeding air.
Intake Plenum... 1 fitting on driver side. Plumb to brake booster. Be sure a check valve is inline.
Carbureted applications...If you are using a carburetor with your conversion, a fuel supply loop should be plumbed in to make the hi-pressure RX-7 fuel pump compatible with the low pressure / volume requirements of your carburetor. The RX-7 fuel pump must have a constantly circulating fuel flow through it for cooling purposes. To make both the carburetor and fuel pump happy, we install a “T” into the fuel line, connecting the pressure and return lines together, to form a path for the fuel to circulate back to the fuel tank. The 3rd leg of the “T” should go to a fuel pressure regulator (available at any auto parts store), then on to the carburetor. Plumbed like this, fuel will just return to the tank through the return line without building any pressure for the carburetor. In order to get the 4-6 psi pressure recommended for the carburetor, some restriction is needed in the return line. An easy way to get this restriction is to use a pair of “Vice Grip” type pliers, and slowly and incrementally crimp the steel section of the return line until there is about 8-10 psi before the pressure regulator. After this is achieved, the regulator can be adjusted to further drop that pressure to 4-6 psi for the carburetor.
Port Injected applications...The stock fuel pump from the injected GSL-SE 13B equipped RX-7 is compatible in both pressure and volume for all but the most modified TPI & LT-1 fuel injected V-8 engines (injected RX-7’s typically run about 45 psi of fuel pressure at the injector). Since the pressure regulator is located on the end of the engine's fuel rail, fuel pressure is automatically adjusted to the requirements of the engine.
Re-plumbing the RX-7's AC system is easier than one might think. We suggest that you re-use the OEM hose fittings/pipes from the RX-7 at the firewall, condensor, and drier. Re-use the OEM hose fittings for the compressor that you are using. Salvaging these fittings will not only save you money, but it will insure that you have the correct fittings for your application. The salvaged fittings will be fitted with new hose and crimp sleeves, and hose length and fitting angle can be adjusted to your exact requirements. The AC system plumbing should be routed as follows...
...large firewall fitting connects to the compressor suction port.
...small firewall fitting connects to the reciever/drier outlet port.
...compressor pressure port connects to top of the condensor core.
...condensor core bottom connects to the reciever/drier inlet port.
After the hose lengths and fitting direction are tailored to your application, return to the hose shop to have your new crimp sleeves crimped onto your new hoses permanantly.
After the hoses are attached, you can take your car to the AC shop to evacuate and charge the system.
If your completed AC system is operating under severe conditions, a small 10" fan can be attached to the condensor core to boost performance.
The electrical part of your engine conversion for the AC system is covered in the electrical section.
2....Considerations & Requirements....
4....Engine / Transmission Installation....
5....Exhaust / Throttle Cable / Accessory Drive / Pulleys....
6....Cooling / Fuel Systems....
7....RX-7 Wiring Harness Connector ID and Circuit Locations....
8....Electrical System Modifications By Circuit....
9....Start-up / Troubleshooting....