Brett's 4.0L SOHC Swap | Ford Explorer Forums - Serious Explorations

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Brett's 4.0L SOHC Swap

Okay, the time has come to start this swap. While everyone was off goofing around in Moab over the weekend, I pulled my old 4.0L and 5spd from my sport.

Here are the details:

The patient - 1994 Explorer Sport 4.0L ohv 5spd manual 151K miles
The donor - 2004 Ranger 4.0L sohc 5spd manual 7K miles

My plan is to use as much of the original 94 electronics as possible. Yes, I could wire in the 04 electronics and computer, but I just don't want to. I'm trying to keep this swap simple so it "could" be done in a weekend.

Other details to sort out are:
Oil pan
Front Dress
Fuel Line
Vaccum lines

Pictures will follow shortly as I take them.

If anyone has done this before and can share their expience, please post in this thread. I believe that this has been done before, but as far as I know, there is not much documentation for a 1st gen 4x4 chassis. I know some ranger guys have done this with some 2wd trucks. There is very limited knowledge about this swap in the early trucks. Sure anyone can swap in 5.0L's with all the adaptors available. Let's hear about the experiences with 4.0L SOHC swap.

I would like to keep this thread on track with useful information relating to the swap. PLEASE do not post dumb comments like "where are the pictures" or "wow, this is cool". Please keep those to yourself.


Time spent pulling drivetrain and cleaning up = 8hrs. Total time = 8hrs.


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Oh baby :)

here's a picture of "Barney" Brett's 94 Sport that will be getting the new drivetrain.

personally Brett I think you may be the first to do this in a 4x4 TTB truck, all the SOHC conversions I have seen (not many) have been hack jobs (90% anyways) into 2wd trucks, many desert guys in CA are running SOHC's with a C4/5 trans. I have heard Mcneil is running 4.0L SOHCs in their Gen I's however so we may contact them for info.

UNCHARTED waters here we come!

Wow that Edge got hammered!!! :eek: :confused: :eek: Parts is parts.

I worked on the new drivetrain some last night. Separated the tranny, exhaust, clutch, and flywheel and mounted the engine on a stand. Here's the stats…

Tranny + Tcase = exact same length btw 94 and 04. This was expected.

Oil pan should clear the chassis. I'll have to be careful b/c it has a cover on the bottom when putting the motor in and lining up the transmission - so it doesn't bottom out on the lift bracket.

Sensors and injectors should all match up. Running this on 94 electronics is the way to go as it looks now. I will have to solder the plugs from the 04 harness to the 94 harness.

Need to figure out air intake tube and air box. - Action Item

Starters are exactly the same.

94 engine mounts will bolt up to the 04 block

AC on the 04 actually sits in the same location as the PS pump on the 94. Clearance issues with the PS box are okay. SOHC is 1/2" wider.

I'm going to try to use the 94 AC line. It will need to be bent and moved slightly. If it doesn't work then I need to figure out a condensor that will work with 04 lines or make a custom line using the connectors from the 94 line.

Exhaust y pipe is exactly the same width and bolts to the stock SOHC manifolds.

Oil pan needs to have a low oil level sensor installed. This is crazy b/c ford actually has a hole in the pan but it is not tapped. So… I need to drill and tap the pan for the sensor. Should be easy enough…

Radiator hoses all match up btw the 2 engines. Slightly longer on the sohc engine.

Time spent last night = 2.5hrs. Total time 10.5hrs

You guys should pay attention here, this conversion is going awesome, possibly could have been running by Monday if Brett was not waiting on a 97 SOHC fuel rail (return style)

I helped him (very little, he did most of the work) tear down the SOHC, remove the A/C, replace a valve cover, basically check it out as far as what he needs to do to get it running with the 94 computer, wiring harness and sensors.
I personally would have to really re consider a OHV to SOHC conversion, if I had a high mileage OHV or tired OHV transmission. If this works the way it looks like it should, I see alot of people running this setup in Gen I's and Rangers....5 speed trucks anyways though it could of course work in front of a A4LD or C4 depending on the computers ability to run a A4LD or similar....we will find out, Brett has a 04 Edge 5 speed to use :)

These two engines are VERY similar, there is even a dummy camshaft in the block to still run the oil pump in addition to the two overhead cams..ignore the SOHC cam sensor, knock sensor and the 94 computer should be right at home....

best part of all is hes gonna use some of my old BII/4.0L parts, hehehe spread the love!

As Jamie mentioned, we tore down the 04 motor to basically a long block. The reason for this is so I can eliminate all the 04 "junk" off of the motor and clean it up using the 94 stuff. There is just too many hoses, wires, and other misc for me on the new engine.

Pictues of the SOHC Engine

Time spent. 2.5hrs x 2. Total Time 15.5hrs


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Do what I say, not what I do......
I would have had this engine installed on Sunday, but I messed up and drilled the wrong size hole for the low oil sensor.

Take my advice and get the proper drill bit and tap before doing anything. I just got in a hurry. I really knew better....

Try finding a thread insert for a 20mm 1.5.... Not in this town.... I can get a brand new pan for $125. A heli-coil 20mm tap set is $120. Hard time finding a used pan b/c no yards want to separate these motors. Solution... I'm going to make my own threaded insert to fix the pan.

Time spent = too much! Should have been 5 minutes!

Pan pictures.


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The low oil sensor....


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Power Steering Pressure Line. I found a shop local in town that will custom make the line I need. The cost is not that much. If anyone knows of a stock application that would work, let me know. However, for now I'll have a custom line made.


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I eliminated all the PCV "heater" junk on the 04 motor. This really servers as nothing more than a bunch more hoses that are not necessary for stronger 04 emissions standards. This is really going to clean up the install. I also welded up the fitting for the upper intake (not shown in pics)

Time spent = 1hr. Total time 16.5hrs



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Nice job fellas. I still need to swap the 4.0 that I got from Jaime. I'm still debating if I should just let my 4.0 blow and then swap a 5.0... Dead Link Removed

Hey, do you know where I could get an 04 Ranger Xtra cab silver driver side door? Good grief!

I would have made you a good deal on that door :)

That motor you have from Jamie was actually a loner I gave him b/c he put a nice sized hole in his old 4.0L. That motor came out of Joes 93 EB, then onto a stand in my garage for a couple years, then into Jamie's BII for a couple years until he pulled it and shipped it to you. That motor ran strong and has always had mobile 1 synthetic in it since day 1. (Joe is the original owner of his 93).

When's the last time you saw one of these harnesses???? I'll probably say never. This is close to the final conversion wiring harness. This harness integrates the 94 and 04 electronics and is routed for the 04 engine. All that needs to be done now is test it and wrap it up with friction tape and tubing. (By the way, I have a bunch of rolls of the original style friction tape available for sale. Contact me for details).

Time spent on wiring (remember I know what I'm doing when it comes to wiring - this may take the avg person a lot longer) = 4hrs. Add a couple hours for circuit research. Total time 22.5hrs.



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What's left of the 04 harness. This was a perfect harness to start with....


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96limitedX said:
this is very to see how it burns out!
I'm going to guess it will look like this:


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Niceley done Colin :)
I vote drop your new 4.0L in over a weekend and then start planning 5.0
You can see the kind of stuff you always run into no matter how much you plan or prepare.

Brett wiring looks factory as usual.
Cleaning up that throttle body hot water bypass turned out nice, similar to what I did with my 5.0L conversion.

Hey can I have some of those extra 04 style wiring plugs? hahaha


Truck runs and drives when I talked to Brett on Saturday :)
Learned some interesting things, but it is a successful conversion!
I am sure Brett will finish this thread soon enough, but I can give some hints; The 94 computer was retained, some sensors were required to be retained with the computer and adapted to the SOHC, some slight wiring changes were required, he will be able to get rid of all codes we believe, and the exhaust needs a small adjustment.

I can't wait to see if he will let me drive it! haha

A very interesting development while I've been gone.

Maybe I missed it, but were there any issues with the black plastic HVAC box?

I'm thinking the old thought of swapping SOHC heads/top end onto an OHV would NOT work.

F14CRAZY said:
A very interesting development while I've been gone.

Maybe I missed it, but were there any issues with the black plastic HVAC box?

I'm thinking the old thought of swapping SOHC heads/top end onto an OHV would NOT work.

There is not much left of the heater box. In fact, I trimmed as much away as I could and the valve cover still comes into contact with it. The 4.0L sohc is taller than a 5.0 conversion.

You cannot swap sohc heads onto an ohv. The blocks are much different.


Very nice Brett. I cant wait to see final pics. Bravo sir, bravo.....

Thanks Brett. What do you suppose could be done to have a functional HVAC box? I was thinking to make one and put it somewhere remotely, like in the cargo area.

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You could re-locate the box on the firewall by enlarging the opening in the firewall while the engine bay is empty.
This is exactly what Ford did on the Gen II as well as angle the box (condensor) a bit to gain more clearance for th eSOHC and 5.0L

Or consider an aftermarket AC system, like the vintage air ($$$$$$$$$$$$$$$$$)
Even when Brett hooks up his AC system I do not expect much airflow given the the shape of his heater plenum, but then again a little bit of ice cold air is far better then nothing...

I drove this truck around the block and let me tell you it friggin ROCKS!
Seriously the 5 speed trans felt just like a brand new Ranger (gee I wonder why since its all new from a 04 Edge) and the Sport had PLENTY of power......awesome conversion.