Some modifications are required to enable this manifold to fit onto an EL (or EB-EL) V8. Here they are, along with some things that I noticed when I changed this, that might make it easier for anyone else thinking about doing this change.
LOWER
The lower is almost exactly the same as the GT-40/Cobra manifolds, as fitted to the ED XR8 Sprint, and EB and EL GT’s, with the main difference being that there is no provision to locate the air temperature sender on #5 runner (as on the HO manifold). On the AU they moved this sender to the ducting between the MAF and TB, which would be the easiest solution, with only an extension of the wiring harness required. Alternatively you can drill and tap a thread for this (I think its a 3/8-18NPT thread) in runner #5. If you wish to maintain the operation of the EGR system you need to drill and tap a hole for the coolant return flow from EGR spacer (I blocked EGR so not necessary). I was fortunate in that the lower I purchased was actually a GT-40 lower (complete with tapped hole at #5 runner), so no tapping reqd for me. All fuel lines, injectors and heater hose components will swap over from the HO manifold. I plugged the EGR port at the head/intake interface to prevent the exhaust gasses heating the manifold unnecessarily.
UPPER
The upper will basically bolt straight on to the new base (not the old HO), but there are a few items that require some modification. You will need 2 extra longer upper-to-lower bolts (if you didn’t get them supplied with the manifold), as the bolting configuration is different to the HO. The vacuum lines under the upper are different, as outlined following.
*At the rear of the explorer there is only 1 off 5mm OD vacuum tube, whereas on the HO there are two (1 for FPR and the other for emissions hook up). You will need a ‘T’ piece (to suit 5mm OD tube), as well as a small length (about 60mm) of 5mm ID vacuum tubing to connect the ‘T’ piece to the 5mm vacuum tube. The standard ‘red’ colored vacuum line from the FPR will fit this new ‘T’. Note that the FPR hose connects with the straight end on the FPR, and the 90 end at the vacuum tube on the manifold.
* The front vacuum line will need to be trimmed, as it is too long. I trimmed this to approximately the middle of the front runner. Be sure to round off the edges of the trimmed tube, so the new vacuum line will slide over easily. If this vacuum hose is damaged, you will need approximately 300mm of 6.5mm ID vacuum hose (do not get 8mm hose or it will be too loose on the vacuum pipe to the charcoal canister).
* The 10mm OD tube at the rear of the manifold is for the master cylinder vacuum. If this hose is damaged, you will need about 400mm of 11/32” ID brake vacuum hose.
* The 9.4 mm OD tube at the front of the manifold needs to be plugged, so buy a proper plug for this.
To maintain a ‘stock’ appearance in the engine bay, I wished to maintain the standard ‘BBQ plate’ engine cover. The cover fouls with the top of the forward most long upper to lower hold down bolt. Rather than cutting the engine cover, I machined approximately 10mm of the bolt boss off, allowing the cover to fit neatly, but it would probably be easier to just grind the cover (if you fit it at all). I fitted a 65mm AU style TB, and needed to trim the cover plate near the TPS units, as they will foul otherwise. Not sure if this is the case if you stick with the std TB. A small amount of grinding was also required near where the solid fuel lines disappear under the cover.
Clean the threads on the manifold before installing. If you did not get bolts with the manifold (I didn’t) you will need some new upper to lower bolts, with the short bolts from the HO manifold too long, (purchase 2 off 5/16” BSW x 1.5” long) and you also need 2 extra long bolts (5/16” BSW x 6” long), as the explorer manifold has 2 off short bolts and 4 off long bolts.
The bracket that holds the 2 off 10 pin wiring connectors to the EGR spacer will need to have a small amount ground off one part of it, as it will otherwise foul with one of the runners, and also one of the fuel lines.
Apart from the above modifications, the installation is the same as for the standard manifold. You will however have to ensure that you fit the back ‘long’ bolt into the upper manifold before you lift the upper onto the car, as it will not fit due to fouling with the firewall if you try to fit it with the manifold on the motor.
Here are some notes on the actual job of changing the manifold.
Begin by firstly thoroughly cleaning the engine down, to prevent any dirt entering the engine once the manifold is removed. Drain coolant and remove the upper manifold. Label and remove the wire connectors from the various sensors and injectors.
It will be necessary to disconnect the couplings of the fuel rails. First check for zero pressure in the fuel system. If the engine has been off for a while there should be no pressure in the fuel lines. Check by covering with a rag, and gently pushing the needle of the Schroeder valve down to relieve the pressure. Preferably do this while the engine is cold (as with the rest of this job anyway – save burning yourself)
Rather than buying the Ford fuel coupling disconnection tool, you can simply use a strip of plastic bottle (eg. Coke) 90 x 40mm. Roll the plastic around the fuel rail (on the side which has the spring visible, the rear of the car), and use this to unseat the garter spring. Push the plastic into the spring, while pulling the other half towards the front of the car. Do this while the fuel rails are still bolted to the manifold. Remove and replace the injectors and the fuel rails off the engine if possible. Use a small amount of engine oil to lubricate the injector ‘O’ rings into the manifold. Reconnect the fuel rail couplings by just pushing together, but check the O rings in the coupling first, and check for leaks upon start-up.
Leave the thermostat housing attached to the lower manifold, as it will give you somewhere to lift it from, as the manifold may be stuck to the heads and block.
Before removing the distributor, turn the motor so that #1 cylinder is at TDC. This apparently prevents the oil pump drive shaft from falling out. Set at TDC by removing #1 sparkplug, and rotating the engine by putting a ratchet on a crank pulley bolt. Put your finger over the spark plug hole, and you will feel air rushing out the plug hole when you are near TDC. Then you can simply remove the distributor cap, and keep turning the crank until the rotor points at the #1 mark inside the distributor base. Record the location of the distributor base (on the engine block) AND the way the rotor is pointing before removing it. When you lift the distributor out (and put it back in) the rotor will turn as it rotates on the camshaft drive gear. When re-installing put it in carefully so that you not only don’t knock the oil pump drive, but also to ensure that the previously marked lines line up.
When re-installing the lower manifold, use guide pins to help guide the manifold in place without disturbing the gaskets. These need to be 5/16” BSW thread x 3” long (I think) approximately. Use a small amount of silicone sealant at the points where the head to manifold and block to manifold gaskets join. With everything back together reset TPS and ignition timing. Check for leaks.
One other thing, with these modifications carried out the engine first idled a bit roughly, initially I thought due to the different operating conditions. I later discovered I had accidently dislodged the injector harness earth lead during disassembly, and hence had not re-connected it. This is meant to be earthed to one of the lower to head bolts, at the back of the motor. This most likely caused a lean operation, and the poor idle.
Good luck. Its not that hard either.
LOWER
The lower is almost exactly the same as the GT-40/Cobra manifolds, as fitted to the ED XR8 Sprint, and EB and EL GT’s, with the main difference being that there is no provision to locate the air temperature sender on #5 runner (as on the HO manifold). On the AU they moved this sender to the ducting between the MAF and TB, which would be the easiest solution, with only an extension of the wiring harness required. Alternatively you can drill and tap a thread for this (I think its a 3/8-18NPT thread) in runner #5. If you wish to maintain the operation of the EGR system you need to drill and tap a hole for the coolant return flow from EGR spacer (I blocked EGR so not necessary). I was fortunate in that the lower I purchased was actually a GT-40 lower (complete with tapped hole at #5 runner), so no tapping reqd for me. All fuel lines, injectors and heater hose components will swap over from the HO manifold. I plugged the EGR port at the head/intake interface to prevent the exhaust gasses heating the manifold unnecessarily.
UPPER
The upper will basically bolt straight on to the new base (not the old HO), but there are a few items that require some modification. You will need 2 extra longer upper-to-lower bolts (if you didn’t get them supplied with the manifold), as the bolting configuration is different to the HO. The vacuum lines under the upper are different, as outlined following.
*At the rear of the explorer there is only 1 off 5mm OD vacuum tube, whereas on the HO there are two (1 for FPR and the other for emissions hook up). You will need a ‘T’ piece (to suit 5mm OD tube), as well as a small length (about 60mm) of 5mm ID vacuum tubing to connect the ‘T’ piece to the 5mm vacuum tube. The standard ‘red’ colored vacuum line from the FPR will fit this new ‘T’. Note that the FPR hose connects with the straight end on the FPR, and the 90 end at the vacuum tube on the manifold.
* The front vacuum line will need to be trimmed, as it is too long. I trimmed this to approximately the middle of the front runner. Be sure to round off the edges of the trimmed tube, so the new vacuum line will slide over easily. If this vacuum hose is damaged, you will need approximately 300mm of 6.5mm ID vacuum hose (do not get 8mm hose or it will be too loose on the vacuum pipe to the charcoal canister).
* The 10mm OD tube at the rear of the manifold is for the master cylinder vacuum. If this hose is damaged, you will need about 400mm of 11/32” ID brake vacuum hose.
* The 9.4 mm OD tube at the front of the manifold needs to be plugged, so buy a proper plug for this.
To maintain a ‘stock’ appearance in the engine bay, I wished to maintain the standard ‘BBQ plate’ engine cover. The cover fouls with the top of the forward most long upper to lower hold down bolt. Rather than cutting the engine cover, I machined approximately 10mm of the bolt boss off, allowing the cover to fit neatly, but it would probably be easier to just grind the cover (if you fit it at all). I fitted a 65mm AU style TB, and needed to trim the cover plate near the TPS units, as they will foul otherwise. Not sure if this is the case if you stick with the std TB. A small amount of grinding was also required near where the solid fuel lines disappear under the cover.
Clean the threads on the manifold before installing. If you did not get bolts with the manifold (I didn’t) you will need some new upper to lower bolts, with the short bolts from the HO manifold too long, (purchase 2 off 5/16” BSW x 1.5” long) and you also need 2 extra long bolts (5/16” BSW x 6” long), as the explorer manifold has 2 off short bolts and 4 off long bolts.
The bracket that holds the 2 off 10 pin wiring connectors to the EGR spacer will need to have a small amount ground off one part of it, as it will otherwise foul with one of the runners, and also one of the fuel lines.
Apart from the above modifications, the installation is the same as for the standard manifold. You will however have to ensure that you fit the back ‘long’ bolt into the upper manifold before you lift the upper onto the car, as it will not fit due to fouling with the firewall if you try to fit it with the manifold on the motor.
Here are some notes on the actual job of changing the manifold.
Begin by firstly thoroughly cleaning the engine down, to prevent any dirt entering the engine once the manifold is removed. Drain coolant and remove the upper manifold. Label and remove the wire connectors from the various sensors and injectors.
It will be necessary to disconnect the couplings of the fuel rails. First check for zero pressure in the fuel system. If the engine has been off for a while there should be no pressure in the fuel lines. Check by covering with a rag, and gently pushing the needle of the Schroeder valve down to relieve the pressure. Preferably do this while the engine is cold (as with the rest of this job anyway – save burning yourself)
Rather than buying the Ford fuel coupling disconnection tool, you can simply use a strip of plastic bottle (eg. Coke) 90 x 40mm. Roll the plastic around the fuel rail (on the side which has the spring visible, the rear of the car), and use this to unseat the garter spring. Push the plastic into the spring, while pulling the other half towards the front of the car. Do this while the fuel rails are still bolted to the manifold. Remove and replace the injectors and the fuel rails off the engine if possible. Use a small amount of engine oil to lubricate the injector ‘O’ rings into the manifold. Reconnect the fuel rail couplings by just pushing together, but check the O rings in the coupling first, and check for leaks upon start-up.
Leave the thermostat housing attached to the lower manifold, as it will give you somewhere to lift it from, as the manifold may be stuck to the heads and block.
Before removing the distributor, turn the motor so that #1 cylinder is at TDC. This apparently prevents the oil pump drive shaft from falling out. Set at TDC by removing #1 sparkplug, and rotating the engine by putting a ratchet on a crank pulley bolt. Put your finger over the spark plug hole, and you will feel air rushing out the plug hole when you are near TDC. Then you can simply remove the distributor cap, and keep turning the crank until the rotor points at the #1 mark inside the distributor base. Record the location of the distributor base (on the engine block) AND the way the rotor is pointing before removing it. When you lift the distributor out (and put it back in) the rotor will turn as it rotates on the camshaft drive gear. When re-installing put it in carefully so that you not only don’t knock the oil pump drive, but also to ensure that the previously marked lines line up.
When re-installing the lower manifold, use guide pins to help guide the manifold in place without disturbing the gaskets. These need to be 5/16” BSW thread x 3” long (I think) approximately. Use a small amount of silicone sealant at the points where the head to manifold and block to manifold gaskets join. With everything back together reset TPS and ignition timing. Check for leaks.
One other thing, with these modifications carried out the engine first idled a bit roughly, initially I thought due to the different operating conditions. I later discovered I had accidently dislodged the injector harness earth lead during disassembly, and hence had not re-connected it. This is meant to be earthed to one of the lower to head bolts, at the back of the motor. This most likely caused a lean operation, and the poor idle.
Good luck. Its not that hard either.