Having that glorious engine built, dyno tested, attached to the transmission, and ready to go in the Mk4 chassis means that our project is close to being finished. For the longest time we had a pile of brand-new engine parts in our living room. Now those components are bathing in motor oil and have a purpose.
This Tech Tip is From the Full Book, HOW TO BUILD COBRA KIT CARS + BUYING USED. For a comprehensive guide on this entire subject you can visit this link:
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After we had secured a Tremec T56 Magnum 6-speed transmission to back our illustrious engine, we learned from Factory Five’s techsupport team that none of their customers to date (as of this writing) had ever installed a T56 Magnum in an FFR roadster. They let us know that it wasn’t a supported transmission for that very reason. So we were on our own, breaking new ground again.
We had to do some engineering exploring in short order, thanks to our desire to go off the beaten path. There were several occasions when we wished we were installing a supported transmission, like a Tremec TKO 5-speed. Still, breaking new ground is something that you might do when you create a replica. Selfexpression is well regarded in the kit-car arena. After all, where is the fun if everyone built the same sort of Cobra replica?
Project 1: Drivetrain Installation
Step 1: Inspect Transmission and Motor Mount Kit
Energy Suspension polyurethane transmission and engine mounts are included in the FFR Mk4 Roadster Complete Kit, along with all the required fasteners. Loosely install these mounts and snug the bolts halfway. The bolts should be held on by a couple of threads or torqued down halfway. They need some wiggle room for lining up the engine and transmission in the FFR chassis. Remove the mounting boss on the bottom of the transmission before installing the engine/transmission. We removed the mounting boss on our Tremec T56 Magnum transmission as a precaution, by shearing off the boss with a hacksaw; you could also use a rotary or air grinder.
Step 2: Install Engine Mounts
Knowing that our T56 Magnum transmission had never been used in an FFR Cobra roadster replica before, we installed the engine mounts but decided to wait to install the transmission mount.
Step 3: Install Starter Motor
Upon trial fitting the Powermaster XS high-torque starter, we realized the three installation holes on the starter did not align with our custom Moroso oil pan. We removed the starter installation bracket from the starter and modified the non-aligning hole with an electric grinder. After working on the non-fitting hole for a while, we managed to get the Powermaster starter installed.
Step 4: Install Engine and Transmission
After wrestling with the engine/transmission, we managed to safely get the engine and Tremec T56 Magnum partially installed in the chassis.
Step 5: Install Transmission A-Frame
We didn’t put the Energy Suspension transmission mount on the Tremec T56 Magnum 6-speed yet. Leaving it off during the engine/transmission install made sense; we wanted to be sure the powertrain would fit. We modified components as necessary to make it work. If you’re using a supported transmission, you can follow the directions in your manufacturer’s build manual. Upon initial mock-up of the Factory Five Racing supplied transmission A-frame mount, we discovered that the beefy Tremec T56 Magnum 6-speed transmission case conflicted with the A-frame mount. Our local car customizer modified the A-frame transmission mount, so we could bolt everything together. To make the A-frame fit, much of the middle part of the frame needed to be removed.
Step 6: Torque Transmission Fasteners
After test fitting the modified A-frame transmission mount, we torqued the fasteners for the Energy Suspension polyurethane mount according to the specs in the manual.
Project 2: Driveshaft Installation
Step 1: Test Fit Driveshaft
The driveshaft spline shaft should have 5/8 inch of play inside the transmission tailshaft. We could not fit this driveshaft in place between the tailshaft of the Tremec T56 Magnum and the IRS differential because it was too long. Based on the measurements we supplied, Oceanside Driveline shortened our driveshaft 2 inches.
Step 2: Install Driveshaft
Install the driveshaft from underneath the car. First, put the spline shaft into the tailshaft. Then screw the four bolts by hand that hold the driveshaft’s yoke to the differential U-joint. Before putting the driveshaft into place, put white lithium grease on the U-joint shaft, so it slides easily into the transmission. FFR supplies special thread locker for use on the threads of the fasteners that go into the differential’s shaft. If you have an FFR Mk4, make sure you remember to use the special thread locker.
Step 3: Inspect Components
With the powertrain in place, turn your attention to installing the pulleys and brackets, as well as the high-performance alternator. According to our professional engine builder, QMP Racing Engines, the Ford 351W engine has more variants—in terms of different components and fasteners used—than most. When it comes to installing power accessories, like alternators, starters, pulleys, etc., the variety of different components can present quite a challenge.
Step 4: Install Front Accessory Pulleys
We aren’t using a power steering pump, air conditioning, or any other power adders on our build, so we opted for a pure March Performance bracket and pulley system that performs well. After you install the system, torque all the fasteners to spec. Use thread locker, locknuts, or lock washers to keep everything fastened together.
Step 5: Install Flex Fuel Lines
With the engine safely in place, measure the length that the flexible fuel lines should be. (We ordered ours from Rupe’s). Measure from where the hard supply line stops in the engine bay to the supply side of the Holley Avenger EFI, and do the same for the return side. Pictured here are our installed supply and return fuel lines.
Project 3: Radiator Fan Installation
Step 1: Inspect Components
To install the Afco aluminum radiator in the FFR Mk4 chassis, use a hack saw, marker, the supplied insulated clip hardware, drill with 1/4-inch drill bit, 3/16-inch hex key, 1/2- and 7/16-inch wrenches, ruler, and flat-head screwdriver. The stainless-steel radiator hose kit (not shown), roadster-cooling system, fan-mounting components, and packaged aluminum are all used.
Step 2: Attach Fan Mounting Brackets
There are four fan-mounting brackets for the FFR Mk4’s electric fan. Push these brackets into the angled tab mounts.
Step 3: Mount Fan on Radiator
Center the electric fan on the underside of the radiator. The radiator’s pipes serve as your guide for placing the fan, so install the fan on the same side as the radiator’s inlet/outlet pipes.
Step 4:Mark Brackets and Tighten Fasteners
Mark the fan brackets to trim off the excess. You can use picks to hold the brackets into position, while marking the bracket. At this point you can also attach the fan to the radiator using the supplied fasteners. Tighten the fasteners that hold everything together before moving to the next step.
Step 5: Temporarily Attach Radiator to Chassis
Temporarily zip-tie the radiator into place on the chassis, with the bottom tied around the lower outlet. (As our project was underway, the radiator was mounted with the drain plug at the top of the chassis. This may be different for you if you have a later FFR roadster kit.) Measure and mark the center of the chassis and the center of the radiator. As directed in the FFR Mk4 assembly manual, offset the radiator by 1/2 inch. Also drill the top flange holes on the radiator to the two small mounting tubular crossmember on the chassis. Then use the supplied hardware to fasten the radiator to the chassis, being careful not to overtighten the bolts.
Project 4: Radiator Hose Installation
Step 1: Inspect Hoses
These FFR-supplied aluminum flexible hoses are pretty trick. The reason they are ridged is because with so many different surfaces, it’s difficult for there to be any coolant leaks. The ridges also enable the hose to be more flexible, sort of like a connected slinky. As far as those rubber hoses and clamps go, the rubber hoses are different thicknesses and diameters, which, when used in concert with each other, prevent any leaks. The smaller sections of rubber tube are used in the adapters for the smaller fittings on the radiator and intake.
Step 2: Attach Top Hose to Radiator Pipe
After mocking up, bending, and cutting the top aluminum hose to the appropriate length, attach the thin- and then thicker-diameter rubber adapters to the top radiator pipe. The different layers of rubber adapters are used to prevent any coolant leaks between the corrugated aluminum, the rubber adapters, and the aluminum inlet and outlet pipes on the engine and the radiator. With this done, tighten the hose clamps.
Step 3: Install Thermostat in Housing
Install the thermostat in its aluminum housing. Notice the first-class O-ring for the GSR aluminum thermostat housing; it’s a good deterent to leaking.
Step 4: Attach Top Hose
Attach the top aluminum hose with rubber adapters to the aluminum fill neck. It may help to have some assistance with this step. For the fill neck to the thermostat housing, simply use the correct-diameter rubber hose. The installation feels solid, but you may swap out the hose to the thermostat housing for a different solution, if it begins to flex and sag. Be sure to monitor the hose and determine its viability. If this solution is problematic, obtain a solid aluminum pipe and the appropriate-diameter rubber hose to mate the aluminum radiator inlet pipe with the aluminum hose. Then use another rubber hose to go from the aluminum pipe to the fill neck and from the fill neck to a rubber hose that is attached to the thermostat pipe.
Step 5: Install Lower Tube
Though the lower tube is longer, it’s an easier installation because you don’t need to install a fill neck in the middle of the tube. Route the tube adjacent to the 4-inch main rail and under the steering rack to the bottom pipe of the radiator. Make sure the lower tube has sufficient slack to enable fitment of the nose aluminum, which is installed when the body is on the chassis. Be certain that the lower tube doesn’t hang down too low; if it does, zip-tie the hose to the frame. Snaking the hose as we’ve done here takes up some of the slack and enables the hose to be well above the ground. After you install the body, you are able to ascertain whether you need to zip-tie the hose to a frame tube.
Step 6: Install Overflow Tank
The radiator’s coolant overflow tank is best installed on the passenger-side F-panel (shown). Start by installing the mounting tabs loosely to enable proper adjustment for final fitment. Mark the holes for drilling and make certain that the tank can be accessed to check the fluid level after the body is on the chassis and construction is complete.
Step 7: Install Overflow Hose
When installing the overflow hose, be sure to attach the hose to the tube that runs off the bottom of the tank, as opposed to the tube that extends up into the tank.
Written by D. Brian Smith and Posted with Permission of CarTechBooks