Engine GT40 Intake Swap Info Needed

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Explorer intake swap.

I got mine off a 96 Mountaineer with the 19# injectors and 65 MM throttle body for $250.

The ACT (Air Charge Temp) sensor will probably need to be moved. The GT 40 lower manifold isn't drilled & tapped for it to go into the intake like the stock manifold was. There is a boss cast into the GT 40, but a machine shop will have to drill & tap the new manifold. The best spot for the ACT is the air box if you don't do the drill and tap thing. You get to cut and splice the 2 ACT wires in order to make them long enough to reach the air box. Solder the wire extensions on the existing wires & use heat shrink tubing to cover the splices. Offset the place where you cut the wires so that you don't have a big bulge when you put heat shrink over the 2 wires to cover & protect them. The air box gets a hole (5/8" or so) for the ACT drilled about 1 1/4" down & 1/1/4" in on the front top side near the upper radiator hose. A brass fitting nut from Home Depot or Ace Hardware secures the ACT into the air box.

If you are very clever, you will find that the ACT connector comes apart so that you can remove the pins. A very small screwdriver releases the lock in the front of the center insert, while another small screwdriver inserted in the back pushes it out. Once the center insert is out of the connector shell, the pins come out easily. New pins are available from AutoZone in a $5 electrical pin kit for Fords. Crimping the pins on the extender wires saves you from having to splice them twice: once to put the connector on and once to extend the wires.

6 ft black 18 gauge wire
6 ft green 18 gauge wire
6 ft 1/4" heat shrink tubing
1 ft 3/16" heat shrink tubing

Measure the 2 extender wires & cut them to length, crimp one set of pins on them. Then mate up the extender pins with the wiring harness & slide the 3/16" heat shrink tubing over them & shrink the tubing. Then slide the 1/4" heat shrink tubing over the pair of wires and shrink the tubing. When you are done you'll have about 1" of wire left without heat shrink tubing on it to strip & crimp the new pins on. Stick the new pins in the old connector shell, assemble it and you are done. It looks as good as factory. Some wire loom can be used to enhance the "Factory Look".





Use the TPS and IAB from your old throttle body. All the EGR passages were there and fit OK. Use you old fuel rails and regulator. You will probably need a new EGR spacer adapter and gaskets. Without the EGR spacer, there is no place to mount the throttle linkage support bracket.

I used the stock water lines on the Explorer manifold and they connected up to the EGR without any problems. I made a “U” out of ½” copper pipe and sweat soldered it together. Then I used it and some hose with clamps to bypass the leaky heater.

The vacuum lines you need are 1 small line for fuel pressure regulator, 1 small line for A/C,1 small line for EGR and another small line for the smog pump. One big line at the back goes to the vacuum tree for the power brake & A/C, one big line goes to the PVC valve. The other big line goes out the front for the carbon canister. In a pinch, one of the small lines can connect to the spare port on the vacuum tree. Cap or plug the remaining lines since they aren't needed.

The stock Explorer linkage didn't come anywhere near fitting, so I made an adapter plate for the throttle linkage so I could use the 65 MM throttle body.

This is what I did:
Make a drawing of the position of the old throttle body linkage arm and its angular position relative to the centerline of the throttle body. Remove the ball stud off the explorer TB to make way for the adapter plate. Drill and tap a 10-32 hole in the linkage parallel to the TB shaft. Make an angle bracket out of 1" angle iron 3/8", drill a 3/16” hole in the center of each one of the legs. Then bolt it on where the hole was drilled & tapped. Then make a circular adapter plate out of 1/4" thick aluminum to bolt the two linkage arms together. Then bolt the aluminum plate to the existing linkage, and the angle bracket. Next mount the arm with the ball stud off the old throttle body on the adapter plate using the drawing to get the angle correct. You will need an aircraft type countersink for one of the bolts that secures the plate to the explorer linkage arm. It ends up being under the arm with the ball stud for the linkage. It works great and looks neat.

The Explorer TB could have been real simple if I had a gas welding torch or taken the TB to a welding shop. Just grind the mushroomed part of the TB shafts so that you can pry the linkage arms off. Then swap the stock arm onto the Explorer TB and braze it onto the shaft. It Takes about 3 minutes or less worth of work with the torch, so it shouldn't cost much.

I didn't have access to a welder, so I fabb'ed the plate in my shop. I took about 1.5 hours to do it, it was a measure, cut, and fit type of operation.

Also see http://www.veryuseful.com/mustang/tech/engine/ConvertingExplorer65mmTB.pdf for modifications to adapt the 65 MM Explorer TB to a Mustang

Vacuum line connections:
One large vacuum line from the upper front goes to the carbon canister

One large vacuum line from the rear goes to the vacuum tree.

One small line in the front feeds the Smog pump solenoid control valves on the rear of the passenger side wheel well..

One small line in the rear goes to the fuel pressure regulator.

One small line in the rear goes to the EGR suction regulator.

One large line in the rear goes to the PVC valve.

Diagram courtesy of Tmoss & Stang&2birds - Typical Vacuum Routing for a Fox stang 5.0:

Diagram courtesy of Tmoss & Stang&2birds - Intake manifold bolt tightening sequence for a 5.0 Fox stang:


Intake manifold to head bolts
--Step 1 96 in/lbs
--Step 2 16ft/lbs
--Step 3 23-25 ft/lbs

See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host) for help on 88-95 wiring http://www.veryuseful.com/mustang/tech/engine/

Here's some tips...

Tools: a good torque wrench is a must have item. A razor blade scraper that holds a single edge razor blade from Home Depot or Ace hardware is another handy thing. Get a Chilton or Haynes shop manual - you'll need it for the bolt torques and patterns. The intake manifold has an especially odd pattern. You'll need access to a timing light to set the timing after you re-stab the distributor. Look in the A/C repair section for the fuel line tools. They look like little plastic top hats. You will need the 1/2" & 5/8" ones. The hat shaped section goes on facing the large part of the coupling. Then you press hard on the brim until it forces the sleeve into the coupling and releases the spring. You may need someone to pull on the line while you press on the coupling. Put some motor oil on them when you put the line back together.

The A/C Compressor comes off with lines still connected. Mark all the electrical, smog and vacuum lines with tags to help you remember where to re-connect them. If you have a digital camera, take several pictures.

Whatever you do, don't skimp on cleaning the gasket surfaces. New gaskets need to seat against bare metal and not the residue left from the old gaskets in order to seal leak free. This is the most time consuming and tiresome part of the job. I suggest that you make good use of a shop vac while you are scraping and cleaning to avoid getting the old gasket material lost inside the engine. Look for little things that need to be replaced like the short hose from the thermostat hosing to the water pump, damaged vacuum lines and hose clamps that are rusted or broken.

Plan on cutting the thermostat to water pump hose, or removing the thermostat housing. Also plan on removing the distributor to get clearance to remove the intake manifold. Remove #1 spark plug, stick your finger in the spark plug hole and crank. When your finger gets air moving past it, stop cranking. Turn the engine until the timing marks line up with the pointer. Now you can pull the distributor out.

My favorite trick that saves time and effort is the stay in place gasket. Be sure that you scrape (don't use a wire brush) all the old gasket material off, then clean all the surfaces with acetone or MEK.

When the surfaces are clean, use weather strip adhesive on the head to manifold surface. Also use the weather strip adhesive on the side of the gasket that mates to the head. When you are done, the head surface and the gasket surface that mate together will have weather strip adhesive on them. Follow the instructions on the tube or can and when it gets tacky, press the gasket down on the head.

Clean the area where the rubber rails mount to the block in front and in the rear with more acetone or MEK and do the same trick with the weather strip adhesive that you did to the heads.

Coat the rubber seals and the gasket area around the water passages with lots of Blue Silicone gasket sealer and put it together. TADA! no leaks, and no gaskets that shifted out of place.

Fuel injector seal kits with 2 O rings and a pintle cap (Borg-Warner P/N 274081) are available at Pep Boys auto parts. Cost is about $3-$4 per kit. The following are listed at the Borg-Warner site ( http://www.borg-warner.com ) as being resellers of Borg-Warner parts:

http://www.partsplus.com/ or http://www.autovalue.com/ or http://www.pepboys.com/ or http://www.federatedautoparts.com/

Most of the links above have store locators for find a store in your area.

Use motor oil on the O rings when you re-assemble them & everything will slide into place. The gasoline will wash away any excess oil that gets in the wrong places and it will burn up in the combustion chamber. Heat the pintle caps in boiling water to soften them to make them easier to install.

Plan on doing an oil change within 2 hours of run time on the engine. This will get the debris and coolant out of the oil pan.

Consumable items:
Upper manifold gasket
Fel Pro 1250 or equal lower manifold gasket set.
Short formed hose between thermostat hosing and intake manifold
6 ft 7/64" or 1/8" vacuum hose
2 ft 1/2" heater hose
1 1/2 ft 5/8" heater hose
Blue Silicone sealer
ARP antiseize or equal for the bolts
4 each 3/4" hose clamps (spare item in case the old ones are bad)
4 each 1/2" hose clamps (spare item)

What can happen if you don’t use the stay in place gasket…

Ask Nicoleb3x3 about the intake gasket that slipped out of place and caused idle and vacuum leak problems that could not be seen or found by external examination. Spay everything with anything you have, and you won't find the leak...

If you plan to keep your EGR system, you need the intake from an earlier model Explorer.
The last couple years used an External EGR, which is not compatible with internal.
The later one is the more desireable one if you plan to eliminate your EGR, since the internal plumbing that you would block off when you delete, is already gone on the later models.

The earlier intakes also have the boss for the IAT sensor (air temp) in the runner.
I don't think ANY years have the sensor boss drilled, as they all use a sensor mounting in the tubing from the air filter to the TB, but the early ones have the boss for you to drill if you don't want to relocate your sensor. The later ones don't even have a boss, so unless you want to relocate your IAT, use the one with the boss. Drilling is easier than relocating IMO, some would argue though... I am just not one to tear into my harness when I could just drill a hole.

Use the Explorer TB as well. It is nearly identical to the Fox TB (except for being higher flow), and not too hard to mod into a performance part that bolts right on.

U-pulls around here sell the intakes for 25-50 bux complete, and the TB might bring 5-10 bux.
I bought a complete setup, TB, rails, upper, lower, heater tubes, injectors, everything... for 75 bux because it was already unbolted for me.

ratio411 said:

The later ones don't even have a boss, so unless you want to relocate your IAT, use the one with the boss.

Click to expand...

So your saying if you use one of the later Explorer intakes that you automatically have to relocate your IAT sensor to the stock air box?

What if you have a cold air intake? Where is the best place to relocate the IAT sensor to?

I just did that exact same swap a month ago from a 96 with the EGR provision, You will see the hole for the EGR in the middle of the bottom and upper where they meet. I opened up the intake to 70mm to match the BBK TB and EGR.

The explorer intake does not have the IAT sensor tapped because like the SN95, the located it in the intake tract tube. You will need to tap the boss in the #5 runner with a 3/8 NPT thread for the IAT and the boss on the back passenger side EGR coolant fitting if you plan on keeping the EGR coolant lines. I picked up the Felpro intake set for the Mustang with the blue rubber end pieces and the separate upper to lower explorer gasket. If you can, grab the t/b ( 65MM vs stock 58MM) , injectors ( 19lb but better spray pattern and skinnier) and heater tube ( you don't have to drill the back of the intake if you use this for the EGR coolant line return). You may also want to grab the heads as well as they are a cheap upgrade.

While you are at the junkyard, find a 94-95 mustang and get the MAF as it is a 70MM. Your stock 58MM one will be a bottle neck if you upgrade the T/B and intake. You'll need to buy or fab up and adapter flange for the MAF.

Exile said:

So your saying if you use one of the later Explorer intakes that you automatically have to relocate your IAT sensor to the stock air box?

What if you have a cold air intake? Where is the best place to relocate the IAT sensor to?

Click to expand...

I have heard people here say they have drilled the runner without a boss and installed the IAT, but since there is no boss there, there is not much 'meat' to the aluminum, and that leaves no room for error. Then every time you take the sensor in/out in the future, you have to be very careful not to strip the threads you have made in the thinner aluminum.

The relocated IAT is in the tubing between the air cleaner housing and the TB.
You could install it into your tubing if you wanted to relocate it, or possibly use a portion of an SN95 air intake tract... which you might like to do anyway to adapt an SN95 70mm MAF. I used the flange from an aftermarket cold air intake to adapt the MAF to a Fox, got it from a wrecked SN95 in the junkyard, the rest of the setup was crushed in a wreck, but the flange was good. I might have found the section with the IAT sensor bung if I had needed it. You might find something similar if you look around. Lots of Mustang aftermarket parts out there, and some are used bits and pieces to use for custom work like this. Make sense?

ratio411 said:

I have heard people here say they have drilled the runner without a boss and installed the IAT, but since there is no boss there, there is not much 'meat' to the aluminum, and that leaves no room for error. Then every time you take the sensor in/out in the future, you have to be very careful not to strip the threads you have made in the thinner aluminum.

Click to expand...

This is what I did.. Yes there was not much meat but I got it to work.