Modular Engine: PI Explorer swap article


Staff member
Sep 12, 2023
Roselle, IL
Vehicle Details
1994 Cougar XR7 DOHC TR3650
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• Pictures

Time for someone to make it a lot easier to get all the info on the 02-05 explorer swap. just want to jot down what parts I re-used, bought new, modified to make this swap work. I’m not entirely finished so this is my work in progress. i know there’s tons of info on the swap but i feel it is spread out too much on here and making this thread would make the swap a lot easier. i will edit this post as i go, or if someone chimes in with additional info.

Q: What engine should I order?

A: Preferably a 02-03 Explorer/Mountaineer 4.6 Block. 04-05's are ok but use an electronic throttle body and egr so you would have to swap over your tb/plenum/and egr. If you have a 94/95 v8 mn12 you should get a 02-03 block so you don’t have to worry about getting extra parts. if you have a 96+ v8 mn12 then it doesn’t matter what block to get seeing how you can just swap over your parts.

Q: Where should i order my engine from?

A: There are tons of great deals on ebay as far as engines go but sadly those dont come with a warranty and we all know ebay has scammers and thieves on there. Not that theres nothing wrong about ebay, i know numerous of people who have got great motors from there. I on the other hand chose Its a great place to find "complete engines", from the oil pan to the intake plenum plus they come as complete as they can minus the obvious like alternators and a/c compressors. Great thing about greenleaf is that they have warranties on parts and labor if you choose to spend the extra dough. I did spend a pretty penny on my motor but i was given a warranty and carfax report i couldnt resist.

Q: What extra parts do i need if i have a 96+ mn12?

A: You will need a 94/95 v8 front timing cover seeing how one of the stud holes on the 96+ cover wont line up correctly or seal. Any SOHC 4.6L v8 front timing cover made in 94/95 will work as long as the casting number on the top left start with "F3AE".

Q: What extra parts do i need if i have a 94/95 mn12?

A: Basically all top end parts such as 96+ Fuel Rails, 96+ Throttle Cable, 96+ EGR System, 96+ intake tube and pcv lines. You will need all the fuel lines after the fuel filter. To use your cruise control cable you will need to fabricate a small bracket to use the cable on the explorer plenum. I know there might be a couple of more parts or some of them listed here are needed so please add.

Q: What parts do i need to swap over onto the explorer block?

A: Oil Pan, Oil Filter Adapter, Oil Dipstick Tube, Tranny Dipstick tube, Flexpate, Cam Sensor, Valve Covers, Exhaust Manifolds, SparkPlug wires, Ignition Coils and brackets, EGR system *96+ mn12's only*, Motor mounts, Crankshaft Pulley, Water Pump/ and pulley, all front accessories such as the power steering bracket/ coil brackets and pulleys.

Q: What gaskets do i need?

A: 90% of the gaskets i replaced are re-useable but did it anyways so it would be a brand new motor to me. here’s a rundown,
  • 1) Timing Cover Gaskets - There are 3 of these and should be replaced seeing how they can rip when swapping over easily.
  • 2) Oil Pan Gasket - This is re-useable, but i replaced mine anyways and remember to torque it down correctly.
  • 3) Timing Cover Crank Seal - This is the rubber seal that’s in the timing cover that sits around the crankshaft sticking out in front of the block. These are re-useable and i re-used the one on the 95 cover i acquired
  • 4) Oil Filter Adapter Gasket - The Oil filter and lower radiator hose are at a different angle on the 02+ explorer blocks so swap over your adapter. The gasket that sits between the adapter and the block is re-useable. I got a new one anyways seeing how my old one was covered in rtv. Can we say motor was worked on before?
  • 5) Valve Cover Gaskets - These are re-useable but i ripped one trying to swap it over so good thing i ordered them.
  • 6) Intake Manifold Gaskets - My block had less then 17k miles on it so i re-used the explorer gaskets. With higher mileage cars these should be replaced.
  • 7) Torque Convertor Retaining nuts - Aren’t gaskets but are made of a soft metal and should be replaced when doing a motor swap.
Part Numbers from Ford:
  • Front Cover Gasket F1AZ-6020-A
  • Front Cover Gasket F1AZ-6020-B
  • Front Cover Gasket F1AZ-6020-C
  • Front Seal for in the Front Cover F5AZ-6700-A
  • Oil Pan Gasket F4AZ-6710-A
  • Oil Filter Adapter Gasket F6AZ-6840-BA
  • Torque Convertor Nuts *Pack of 4* 378941-S441 or MM-169-H
Tools/Equipment/etc needed or recommended for swap:
  • Impact Gun w/ at least 250ft/lbs of reverse torque
  • Air Compressor strong enough to support air tools
  • Torque Wrench
  • Pulley Removal Tool
  • Ratcheting Wrenches *Makes life 50 times easier*
  • Metric sockets ranging from 8mm-18mm in both impact and regular styles
  • Ratchets/extensions/universals/gasket scraper/pry bars/etc
  • Engine Hoist and chain
  • Engine stand
  • 4 Quarts of Tranny Fluid to fill up torque convertor
  • 5 Quarts Engine Oil
  • Oil Filter
  • 2 Gallons of Coolant and Distilled Water. Distilled water is like 2.39 for 2 gallons at Albertsons
  • Some Power Steering Fluid
Some parts to think about replacing/upgrading while motor is out:
  • Motor Mounts
  • o2 Sensors
  • Torque Covertor
  • Sway Bar
  • Exhaust Manifolds/Long Tube headers
  • U/d Pulleys

Taking care of the temp sensor and rear nipple problem.
On the intake manifold off the 02+ explorer block there are a couple different issues to look at. If you notice the nipple on the back of the intake it is not the same as our mn12’s setup. Also, there are no coolant temp sensors on the aluminum crossover. There is only one temp sensor located on the drivers side cylinder head on the explorer block. The issues are, what do we do to the crossover? What do we do to the manifold? The answers are simple.

For the crossover just remove the nipple on the drivers side and replace it with a temp sensor off your old crossover. It should be the sensor with the centered key slot to allow your stock wiring harness to match up with it. As for the second temp sensor, just use the temp sensor that’s on the drivers side head. Re-use the 02+ wiring harness’ connector to that sensor and solder or splice the wires coming out of that old connector to your second temp sensors wiring on your stock wiring harness.

For the nipple on the back you can either have it drilled and tapped to allow you to attach the hose to the back of the manifold, or you can simply extend the heater hose going to the extra nipple on the passenger side of the aluminum crossover. This is what I did and i will update if there are any issues. here are some pics

For Pics of my motor progress go here

If the 02-05 explorer motor and the 99-04 mustang motor were both out the vehicle they would put out the SAME power. People think the explorer motor is slower than the mustang motor seeing how from the factory the explorer had 235ish horsepower and the mustang had 260. The ONLY reasons why the mustang had more is because of more aggressive ecu tuning and true dual exhaust. The explorers are underpowered ecu wise AND have single restrictive exhaust which has lots of bends. The only reason why its smarter to go with the explorer motor is cuz is about 90lbs+ lighter than an iron 4.6 ie: the mustang motor. The cranks on the explorers are designed after if not related to the lower end cobra blocks. Cobras and explorers are the ONLY 4.6 blocks with 6-bolt main crank caps to handle more abuse. The iron blocks have 4-bolt mains.

So STOP saying the explorer swap isnt a feasable swap!! lol

More info to come. Please add/edit any info you can.

~*~*~*~Thanks to 95xBird and timb for answering all my annoying emails and helping me~*~*~*~


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