Brett's 4.0L SOHC Swap | Page 6 | 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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Neat swap, did you get back to driving it again?

Yep. Put about 20K miles on it. It's not my DD any longer, so I don't a bunch of miles on it every year. It works, and is reliable.

I'm planing a new build. Starting with another frame and going with a totally different drivetrain.


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This is the best programmed forum I know of.

But could someone figure out how to remove those pictures of a woman or cowboy that have begun to pop up in front of the engine pictures. They are the only nuscance so far.

Nothing new with it. I don't drive it much anymore. I will get back on it someday.

thanks to all this info online and other forums too, I swapped a 99 explorer SOHC 4.0 into my 90 ranger 4.0 ohv chassis and kept the obd 1 ECM to run the obd 2 motor. every sensor swapped over from block to block except one coolant temp sensor i spliced to a new sensor, the low oil sensor is tucked away not being used, the TPS wires had to be lengthened for my wire tuck, just so turns out my 99 engine only had the cam sensor on the valve cover and the jackshaft cam sensor was obsolete? so there was no delete there. I changed the sohc returnless fuel style to the return style from a 97 sohc, the wiring harness for the ohv didnt match the SOHC alternator, so I mounted the OHV alt to the motor with 2 bolts not 3 but kept the sohc pulleys and power steering box. I decided after the motor was dropped in that there was no room to work on it near the firewall, the a4ld dipstick was smashed between the firewall and the heads, thats the only room there was, so I got a buddy that worked at a welding shop to fab 2" diameter 2" tall solid round stock steel disks/pucks for all my body lift blocks. the cab and bed are now both lifted 2" off the chassis. I installed the torque converter wrong when I originally did the swap so my transmission was ruined but the engine ran.

I must note, I left the stock exhaust Y pipe on the chassis and the new sohc motor fit it no problem. The 7/8 bolts on the a4ld mating to the sohc is true, the 8th hole is just not tapped on the block. after the a/c delete and the alt switched to the OHV alternator, I bought a 71.5" belt that seems to start out a little tight but fits great. The EGR was removed and blocked off on both sides. exhaust side I made a steel cork and press fit it into the exhaust nut, then welded it in place, intake side I found a rubber expansion plug from the parts store for $5 or so. The ohv motor mounts were simply unbolted and bolted to the sohc with no modification and the motor went into place totally fine after a fight.

The throttle/trans kickdown cable plate near the throttle body I used the 90 OHV plate and cut it, folded it on a bench vice to fit, custom mount with a bolt and washers, the dipstick was changed to the 4r55e/w or 5r55e/w transmission dipstick tube from the 99 sohc because the ohv dipstick wouldnt fit.

The rubber intake tube from the sohc fit to the old 90 airbox location and gave me 2 holes, one for the intake air temp sensor and one for vacuum lines on the plenum, still figuring out how to add the carbon valve to the vacuum lines.

Also the 99 explorer I pulled the sohc from came with a block heater so now my 90 ranger has a block heater, reminds me of my 73 ford 7.8l v6 diesel I just sold with its block heater. their pretty damn useful too

Another modification to make my motor fit, I wanted to wire tuck as much as I could so I got all the injectors wires coming from the valley pan and not from the valve covers. so I took the upper intake plenum and used a band saw and a bench grinder to remove excess material near the injectors for the wires.

Im currently having problems with the heater blower motor box. of course I removed the factory heater/ac box and I bought a heater only box from a pick n pull, but it still needs alot of material taken out of it even with the 2" body lift.

I hope all this is helpful, I was annoyed when I first started because of the lack of the explanation of the specific work involved for this swap and id just like to share what I had to do to make it work to make it simpler for people to plan out this swap in the future. I would really like to point towards the fact that this swap is very close to plug n play as long as you dont forget to seat the tq converter right and fry your auto trans fluid pump like I did. Ive almost got a new junkyard tranny in it anyway and ill be able to use it as a daily driver.

Sorry that I keep pulling this thread back from the dead but it feels like im adding to an online book of knowlege, I took a video of my SOHC in the engine bay and it running because the internet simply lacks it. I hope im not violating the explorer forum terms of service in any way, but heres my truck.

bear with me this is my first engine swap, im 19 almost 20 and this project is nearly complete

Im 3 months into owning this truck,bought the truck for $340 1st month the plan changed from stock/oem headgasket fix to finding a cracked head. found a 99 explorer wrecked on craigs, bought the sohc motor for $150 still attached to the front chassis half, torched off the explorer. the 2nd month was wasted because the engine was in, the entire time the engine wouldnt start because the coil pack plug was upside down, 3rd month of this project I realized I didnt seat the tq converter into the oil pump in the a4ld ran the trans for awhile with no lubrication, tore it apart, bearings are scored. went to pick n pull and pulled an a4ld for $130 + $30 core, well I installed that and it was also faulty so im going to tear it apart and return it for a pick n pull M5OD.

It also has a power steering leak, and ive waited to fix that until it moves, thats what the squeek/ or whine comes from in the video. I feel like I need to decrease the injector flow rate with smaller injectors too because the idle may be too high, or once the iac adjusts it might be okay.

sept 1st is my birthday, then im going to manual 5 speed swap my truck, feel like thatll be another month, damnit.

Well done, and you are learning what's it's like in the real world of repairing a vehicle. New issues pop up, and it almost always takes longer in the end.

BTW, your tachometer is way off. It sounds like it's getting down to the 750rpm range when the tach showed 2000 near the end.

The engine runs a little rough, if the tune up stuff is all good(plus etc), begin checking the fuel pressure and connectors leading to the injectors, coil packs etc.

Thanks, the auto tranny started to work, I was low on fluid because I used a 5r55e/4r55e/w dipstick tube and dipstick so the correct "Full" line should be aprox an inch and a half higher than indicated.

I do have a friend that used to own an exploder that said my idle didnt seem correct with my tach in person, Im not too familiar with this engine so I wasnt too sure until you said it, think thats a sign of my crank position sensor going out? or could it be the cause of other problems?

Yeah I do have a pretty good idea of how to diagnose engine problems already, I used to work at a diesel shop, aiding in the rebuild of semi inline 6's. tqing head bolts to 350 then 450 ft lbs with a 3ft tq wrench, thats all fun. The fiero I had I replaced the head gasket 3 times within 2 years and the 3rd time I replaced the cylinder head, it had cracked between every valve in each individual cyl of that 2.5 iron duke.

The 1960's gmc diesel motor I had in my 73 ford I adjusted the valve lash for. Im also living at someones house, paying my rent as working on their vehicles. 12 months of living has costed me a 95 XJ 4.0 inline 6 rebuild w/ a melted piston, I replaced a timing chain on a 94 tacoma SR5 22re, injector cleaning and intake manifold gaskets on an 85 pontiac fiero gt v6, and soon im looking at a 2001 subaru ej25 SOHC rebuild.

Anyway back to the point.....

tomorrow im going back to pick n pull for finishing parts and today I tore my engine down, I saw my fuel rail vacuum line was folded in half, and my intake mounting surfaces were not flush, so im also getting an intake gasket kit tomorrow.

Also when I did the swap the SOHC spark plugs had a HORRIBLE gap, they were so gone so I tossed them and used the OHV spark plugs, Yeah I might buy SOHC spark plugs tomorrow. My engine not only idling rough on all the above, is still being fed regular fuel, so I may go with some premium soon.

Next few days ill get things dialed and shoot a new video for this forumn

Im sorry to have invaded your forum and stolen your thunder and lightning brett, which is why I decided to get off your thread and start my own. Here is my thread which ill try to include as much detail about my 4 liter SOHC swap with an OBD 1 computer. My main goal here is to make this swap as simple, clear, and straight forward as I can to new & old builders alike.

No thunder and lightning stolen here. glad you have your swap done and all is working.

I did my swap about 12 years ago now, and have racked up a lot of miles on it. I'm going to be swapping out to a v8 soon.

Well I have recently completely finished my entire 4.0 SOHC swap write up on my page and im bridging the gap between our two pages by adding your URL to my page. I look at these forums as the next generation of a library, I want to spread knowledge and make it as accessible as possible to anyone who needs this knowledge. I couldn't have done my swap without Brett's SOHC swap write up and I definitely spent a few nights reading these pages over and over again looking for help and hoping I could find my answers somewhere written and lost in these pages. I may have explained my work involved in my truck in greater detail but I know for a fact i've still left out a couple of problems, but who would turn a wrench if they cant problem solve?

Id also like to point out that my page has encouraged another explorer forums new member to do their own SOHC swap and they have also been able to make theirs run, the way I see it is once the latest generations of mechanics or enthusiasts try to swap fuel injected motors, figure out the quirks and spread their knowledge, a fuel injected motor swap of all different kinds may just become much easier and more common like the carbureted motors are today. Im seriously writing in these forums for the future, planning for the future.

Ditto, it's all about helping others. My posts get wordy or extra detailed sometimes, but the point is for others to read it and possibly help more people.

hey brett, are you still on here? im about to start on the exact same swap and have some questions about what wiring had to change? i know its been a long time but thanks for any help.

Ill send Brett an email show him this thread. He is still around he is just a very busy dude
Until you posted here I did not even know this thread existed!!!
@Brett check it out

There is a ton of wiring that needs to be changed. Mine is a 94 Explorer and I used an 04 Ranger. There are a ton of differences between 93-94 and CA and 49 state emissions. Also the SOHC motor had a number of changes between 97 to 12.

Lets start with what year donor motor you are using and the spec's on the truck you are putting it in. Also are you running an auto or manual. Is this going to be a race truck to meet certain class rules?

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first of all. thank you for responding!
1999 explorer 4.0 sohc going into a 1993 ranger 4.0 ohv
computer is currently custom tuned and will be again for the sohc.
the truck currently is and will be running a full manual c4 trans. ZERO wiring going to the transmission. i have the necessary items to mate the trans to the sohc as i know the bolt pattern on the main is different between the two.
so mainly my focus is ONLY engine harness wiring.
it is a "race" truck.