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
AC
Front Dress
Fuel Line
Vaccum lines
Electrical

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.

Thanks,
Brett

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

 

[410Fortune]

You should use a 93 ranger 5 speed PCM if you are not already

 

[Brett]

If the C4 is bolted to the OHV now, it will bolt to the SOHC. I assume that it is using a C5 bellhousing. There is 1 bolt that is not the same on the top RH side of the motor between the OHV and SOHC patterns. Which series are you planning to run this truck in? Best in the Desert / SCORE / etc.?

 

[dezertranger]

yes the c4 is mounted the the ohv right now. been driving on it for about 3 years now. ive mounted some c4s in sohc trucks so im familiar with mating the two.
the truck is mostly just built for fun desert trips, i plan to run some SNORE or MORE races soon. score and bitd are $$$$$ but 2021 mint 400 might be a possibility now that they added a 1400 class to the roster.

 

[Brett]

Cool. I'm more familiar with SCORE and BITD as I work on some of these trucks. Let me know if your 93 has a cam sensor and egr or not.

 

[dezertranger]

nice. the truck does have egr right now but ill be getting rid of that on the sohc and tuning it out of the computer. From what ive gathered from here is i need to run the following sensors from the ohv:
MAF
IAC
crank position sensor
oil level sensor (hole needs to be drilled and tapped)
TPS
i will be mounting an external fuel pressure regulator so that takes care of the return for the fuel

what do i do for injectors? use sohc injectors or use ohv injectors? what wiring needs to be changed if using the sohc injectors?
what about coil? sohc or ohv coil, and of sohc, what needs to be changed wiring wise to use that.

Thanks!

 

[Brett]

You will need to pay attention to pin locations and wiring + - when using the sensors. I used a combo of 04 and 94 sensors.
MAF - use one compatible with a 93 computer.
IAC - use the SOHC as this is usually tied to the intake you are using.
CPS - Use the 93 sensor
Cam sensor - if you have this, the SOHC sensor is in the valve cover and can be wired to the 93
TPS - should be able to use either 93 or 99.
EGR and DPFE - use the 99 to keep things simple. It will wire to the 93.
Coil - exact same between OHV and SOHC

On the oil pan, the SOHC pan will not clear the factory cross member. If you have cut that out, cool. Otherwise you will need to switch to the OHV oil pan and pickup. Also the crankshaft main bolts will need to be swapped to the OHV if using the OHV pan.

On the injectors, use the 97 SOHC rail b/c it just bolts in. You can use either injector or even a larger injector. Wiring is simple for injectors Just 2 wires so if you need to change the plug, it's simple enough to convert.

 

[dezertranger]

is this what im going to be looking for? if so im 90% sure my ohv engine does NOT have it.

 

[Brett]

Yep!

 

[dezertranger]

where does the sohc oil pan hit the crossmember? i have alot of it cut out but dont want to take it all the way out
to ad, my truck is 2wd. not sure if that lower cross member is the same between models

 

[Brett]

The SOHC pan would hit the factory cross member on a 4x4 frame. The OHV pan is shaped differently to go around the cross member. When changing to the OHV pan, be sure to pull out the balance shaft on the bottom of the SOHC motor if it has one. Not all SOHC engines have them, but mainly if they originally were in 4wd Explorers they would be present.

 

[dezertranger]

thank you for the info. ill see if it hits the 2wd cross member. my beam pivot brackets have a portion of em that bolt towards the center of the crossmember so i definitely dont wanna take it out.

 

[Stic-o]

The SOHC pan would hit the factory cross member on a 4x4 frame. The OHV pan is shaped differently to go around the cross member. When changing to the OHV pan, be sure to pull out the balance shaft on the bottom of the SOHC motor if it has one. Not all SOHC engines have them, but mainly if they originally were in 4wd Explorers they would be present.

This is not entirely correct. I have successfully fit my '00 SOHC in the '91 Navajo without trimming any of the 4wd cross member, and although very close, it does not hit. I'm using custom engine mounts from @Brian1 and a extra 1/4 plate for as a spacer. I can add pictures if needed.

 

[dezertranger]

i learned that the auto fab motor mounts that i already have lift the sohc out of the way of the crossmember. so were all good there

 

[donalds]

Old thread but a good thread

 

[dezertranger]

okay so upon further review, i do have the rear cam sensor on my ohv, so i will have to find a wire diagram and wire it to the sohc one.

 

[dezertranger]

@Brett did you have the cam sensor on your ohv? any tips on converting the wiring to the sohc? im reading that they run off different signals and voltage and cant be wired to run across platforms

 

[Brett]

This is not entirely correct. I have successfully fit my '00 SOHC in the '91 Navajo without trimming any of the 4wd cross member, and although very close, it does not hit. I'm using custom engine mounts from @Brian1 and a extra 1/4 plate for as a spacer. I can add pictures if needed.

Of course you would be able to make it clear with custom motor mounts and a spacer....

I am referencing the stock motor mounts. They will not allow the factory SOHC pan to clear the Gen1 cross member.

 

[Brian1]

Of course you would be able to make it clear with custom motor mounts and a spacer....

I am referencing the stock motor mounts. They will not allow the factory SOHC pan to clear the Gen1 cross member.

To clear things up a bit about @Stic-o 's post about the motor mounts I build and sell. My mounts are 100% built to the 1st Gen stock mount dimensions and are a direct bolt-in replacement for them as well. Stic-o is therefore making his pan clear with only the 1/4" spacer he made + whatever distance stock mounts sag with weight on them since mine will not do that. So yes they are "custom" in a sense but the dimensions that matter in this instance are the same as a stock motor mount.

 

[Brett]

@Brett did you have the cam sensor on your ohv? any tips on converting the wiring to the sohc? im reading that they run off different signals and voltage and cant be wired to run across platforms

I will have to look up my wiring notes for this. I've had mine wired in since the conversion and it has never had a cam position code. I believe all 94's do have a cam sensor as do some 93's. In the EEC IV, the cam sensor is used mainly as a reference for the computer to fire the correct injectors at startup.

The SOHC has a dummy cam shaft in the middle block to run the front and rear timing chains. The SOHC has a oil pump drive that runs off this shaft. There was a difference between the OHV and SOHC cam sensor / oil pump drive length and I could not simply swap this out.

 

[dezertranger]

okay let me know. really appreciate all your help sir