1989 Ford Mustang GT Intake Installation - Air Apparent
Increase Your 5.0's Induction Capabilities With The High-Flow, Direct-Replacement Edelbrock Performer 5.0 Manifold
From the August, 2003 issue of 5.0 Mustang & Super Fords
By Mark Houlahan
Photography by Mark Houlahan
The Edelbrock Performer 5.0...
The Edelbrock Performer 5.0 intake manifold comes with a lower plenum, an upper plenum, a plenum cover, a plenum gasket (upper to lower), a plenum cover gasket, attaching hardware (upper to lower), and a gray powdercoat finish (upper only). The long runner design will yield nice, streetable torque on a decent-breathing engine, and the upper and lower plenums are CNC port-matched to enhance performance.
As the grandfather of aftermarket 5.0 intake manifolds (we consider Ford Racing Performance Parts' GT-40 a factory performance part), Edelbrock's Performer 5.0 stayed in tune with the market and listened to racers. Through the years, the original Performer 5.0 has been joined by the Performer RPM 5.0, the Performer 5.0 RPM II, and the Victor 5.0 manifolds-each one directly aimed at specific airflow needs. Edelbrock has also tweaked its manifolds' looks and performance as well.
There was a time-maybe before many of you could even drive or think about owning a Mustang, but nonetheless, there was-when you would be hard-pressed to find a performance part for the 5.0 Mustang. Turn on your time machines and come back with me to 1989. The 5.0 movement was just getting under way. Ford helped fuel the fire by offering a 5.0 LX Sport model with all the GT features but in the smoother and sleeker LX body.
Aside from a set of Flowmaster mufflers, a Hurst short-throw shifter, and a K&N direct-replacement panel filter (the standard performance upgrades of the period), there wasn't much to be found for fuel-injected 5.0 engines. Sure, there were a few things just emerging on the market, such as rearend gears, underdrive pulleys, and a few aftermarket camshafts. But the real serious parts such as heads, intakes, and superchargers-stuff we take for granted today-were a few years off. The GT-40 intake with its hand-welded inlet tubes was but a prototype in late 1990 and into 1991 before it made production. The only aftermarket aluminum cylinder head was the TFS Street Heat, now known as the Trick Flow High Port. Today it takes both hands and feet to count the number of aluminum heads on the market.
Here's what our '89 GT looked...
Here's what our '89 GT looked like before we began. At this point, a MAC cold-air kit, Crane 1.7 roller rockers, and a Ford Racing Performance Parts throttle body/EGR spacer were the only enhancements to the engine. The upper intake has been off to install the rockers, but the lower intake has never been removed from the engine.
Seeing the 5.0 movement gain momentum-some have likened it to the "'57 Chevy of the '90s" in the demand for the car and the desire to modify it-Edelbrock sent its engineers to the drawing board to come up with performance pieces for the 5.0. The first items to come out of the Edelbrock shipping department were induction-oriented, the most notable being the Performer 5.0 manifold.
Many years ago (it was early 1993, if memory serves) I installed one of the first Performer 5.0 manifolds on my '90 LX for testing in our sister magazine Mustang Monthly. Everyone stood around the shop in awe as the intake was pulled out of the cardboard box. We were witnessing something-the dawn of a new age in performance. Every person in that room had to look at the manifold and touch it with their own hands.
The Edelbrock manifold was just the beginning. By the mid '90s the 5.0 performance market was in full swing. Nitrous, blowers, stroker kits, intakes, cylinder heads, suspension, electronics-you name it, it was available for the 5.0 Mustang. We witnessed a phenomenon that may not be replicated again. The time was right, the economy was right, and the car was right.
What does this little history lesson have to do with installing an intake manifold, you ask? Plenty. If it wasn't for the Edelbrock manifold and a few other companies' products that got the ball rolling, many of us would have long ago ripped the fuel injection off our 5.0s and thrown on a carburetor and a single-plane intake in its place. Since the Performer 5.0 is where many a young 5.0 owner started in the quest for performance, so shall we.
After disconnecting the negative...
After disconnecting the negative battery cable, begin the intake swap by disconnecting the throttle inlet tube and all the intake's sensor connectors and vacuum hoses. If you think you'll have a problem hooking everything back up later, use tape to mark where these items are connected.
The '89 GT you see here has already benefited from articles on installing roller rockers and a stouter ignition system. Now we'll get more serious with an intake swap, and soon, the installation of a camshaft. History does indeed repeat itself.
Better Stock Up
Replacing your intake manifold takes only a couple of hours in your driveway using standard hand tools. However, there are a few "gotchas" to be aware of so you can plan accordingly and minimize your Mustang's down time, or avoid having to drive your girlfriend's Honda Accord [Tell her to buy a Focus.-Ed.] to the parts store.
* When you purchase the manifold, you get just that-a manifold. The intake will have a gasket for the upper to lower plenum junction, and side cover in the case of the Edelbrock, but that's it. You're on your own for intake gaskets to the cylinder head, throttle body gaskets, and a thermostat-housing gasket.
* Speaking of thermostats, now is the perfect time to upgrade to a 180-degree performance model.
Don't forget the throttle...
Don't forget the throttle cable (it's a common mistake). Remove the two 10mm bolts now; otherwise it will be difficult to free them with the upper plenum loosely sliding around. Use a flat-blade screwdriver to pop the linkage free of the throttle body.
Six bolts hold the upper plenum...
Six bolts hold the upper plenum to the lower-two in the front, two in the rear, and two under the removable plenum nameplate. If your intake has never been removed, there is a small bracket on the driver-side rear of the manifold that needs to come off.
With the six bolts removed,...
With the six bolts removed, the upper plenum should easily give way with a simple bump of the hand. It can then be lifted off the lower plenum. Go slowly in case you've missed a connection or hose. It's good to have a helper at this point so you don't have to set the manifold down.
To gain access for removing...
To gain access for removing the lower intake plenum, you'll need to remove the distributor from the block. Begin by removing the distributor cap and wires. Use a china marker or a permanent marker to note the position of the rotor in relation to the cap adapter. Finally, unbolt the distributor hold-down and pull the distributor up and out. As long as the engine isn't cranked, the distributor can be dropped back in by marking the lines back up. Plug the distributor hole with a rag or paper towel.
* Inspect the cooling-system hoses and replace them during the intake swap. You'll be messing with the heater hoses, the front coolant transfer hose, the EGR cooler hoses, and the water-pump bypass hose during the job, so check them and get new ones now, not while the car is apart.
* Fuel-line disconnect tools are required for Ford's spring-lock fittings. The tools are inexpensive, so buy the entire set for future work on fuel and A/C lines.
* Since you'll be draining the coolant for the job, why not flush the cooling system and add fresh coolant on the refill?
* Most intake-manifold gasket sets come with a new distributor O-ring. If your gasket kit doesn't have an O-ring, be sure to get one. Most of the time the O-ring is so hard from heat, it simply breaks away. This is a common oil-leak path.
* Because you have to swap fuel rails and injectors from the original manifold to the new manifold, the old injector O-rings might give you some trouble with cracking or hardening. New injector O-rings from your Ford dealer are good to have on hand during the process.
Usually the coolant transfer...
Usually the coolant transfer tube is removed from the lower intake plenum before the intake is freed from the grip of the intake gaskets. But oftentimes, and in this case, the nut and stud that secure the rear of the tube (arrow) are stubborn and will not release their grip on the tube. If you're lucky the stud-head bolt and nut will rotate together with some manipulation. If this is the case, remove the other 11 intake bolts first and remove this bolt last (as it will lift the intake).
Here's where you'll need the...
Here's where you'll need the fuel-line disconnect tools. We're using the Ford/OTC style that wrap around the spring lock, but the parts-store versions will do the same job. Disconnect the two lines and move them out of the way. If you haven't drained the coolant yet, do so now. Remove the two hoses from the front of the intake at the coolant tube and thermostat housing.
Once all 12 bolts are removed...
Once all 12 bolts are removed and the injector harness is disconnected from the main PCM harness (don't forget the HEGO ground on the back of the driver-side cylinder head and the oil-pressure sending unit wire), separate the intake from the heads, pulling the intake back and up to clear the A/C lines.
The Edelbrock lower manifold...
The Edelbrock lower manifold features 1.02x1.85-inch ports (at the cylinder head) and CNC-matched port openings (at the upper plenum). The lower intake is physically taller than the stock manifold, but overall height difference is minimal. The lower manifold has all the stock provisions for the EEC IV system-just reinstall the parts listed in the previous caption and you're ready to go.
Here's some dirty work. Use...
Here's some dirty work. Use a gasket scraper, razor blades, sandpaper, or whatever works for you to strip and clean the cylinder head and block surfaces of all remaining gasket material. Leaving old gasket material behind can cause a leak, so be diligent in your cleaning here. Use shop rags or paper towels to block off the ports to prevent gasket shards from going into the combustion chamber.
With the old lower intake...
With the old lower intake mani-fold on a workbench, remove the fuel rails and injectors, the temperature sending unit, the EGR cooler-hose fitting, the coolant passage plug, the thermostat housing, the ACT sensor, and the coolant transfer tube (if not already removed) from the intake. Clean everything and apply fresh thread tape or Teflon sealant where required.
One new item to install on...
One new item to install on the Edelbrock intake is this oil baffle situated under the PCV valve opening at the rear of the intake. Position the steel baffle and tap the twist rivets into place to secure the baffle. If you don't install this baffle, excessive oil will be sucked into the engine via the PCV valve and hose of the upper intake plenum.
Flipping over the manifold...
Flipping over the manifold reveals the location of the PCV valve. If you haven't already done so, remove the PCV valve breather screen from the old manifold and slide it into place. Clean and dry the PCV valve grommet. Apply a light layer of silicone to the grommet and then slide it into place over the PCV breather screen. The silicone will prevent the rubber grommet from pulling out during PCV valve servicing.
After cleaning the items removed...
After cleaning the items removed from the old intake, reposition and install said items onto the new Edelbrock lower intake. Leave the coolant transfer tube off for now, as it will be installed in the car after the intake manifold hardware has been tightened. Install the studs in the lower manifold and place the gasket over the studs. Adding the injector harness at this time is also up to personal choice. We put ours back on the manifold once it was installed on the engine.
The upper plenum is less complicated...
The upper plenum is less complicated than the lower. Simply swap the vacuum tree and other fittings to their identical places on the new Edelbrock manifold. On this 14-year-old car, most every hose under the intake was crumbling. We stocked up on 1/4-inch hose and various sizes of vacuum line, replacing everything with new hoses for a trouble-free start. Don't forget to plug unused ports and holes.
With the upper manifold ready...
With the upper manifold ready to go, all that's left is the throttle body and EGR spacer assembly. You can install them onto the upper plenum first (as we did) or after the manifold is secured to the lower plenum. Carefully line up the mounting holes with the studs and lower the upper plenum into place. The A/C line from the dryer will undoubtedly be in the way, so lift it up to clear the upper plenum.
Gasket brand is your choice-just...
Gasket brand is your choice-just make sure the port openings match those of the manifold. A gasket sticking out into the airflow of the port robs power. Use a small bead of nonhardening Permatex No. 2 or silicone around the coolant ports of the cylinder head before laying the gasket into place. For the end seals, some people use strictly silicone, but I've had good luck with the cork and rubber end seals when secured by Permatex No. 2 on the bottom and a thin layer of silicone on the top. Bolt down the intake manifold using a torque sequence from the center out.
The nuts and lock washers...
The nuts and lock washers can be slid over the studs and snugged down finger tight, but not before installing the center intake bolt through the open side of the upper plenum. Using two fingers or needle-nose pliers, drop the bolt into the bolt hole and start the bolt before tightening any of the retaining hardware. Once all the retaining hard-ware is snug, tighten the upper manifold, working from the center outward.
Finish the installation by...
Finish the installation by securing the upper plenum cover using the provided gasket and Allen-head retaining hardware. Reconnect the throttle cable, the wiring, the vacuum hoses, and the induction tubing. Reinstall the distributor, and you're all set.