1997 4.0L SOHC with OHV Engine Management?

[Nipplechops]

I searched and couldn't find this topic covered previously.

Anyways, what I am wondering is if a SOHC 4.0L from a 1997 Explorer has ever been (or could ever be) made to work with an older OHV engine management system. I am currently building a 1988 X-cab Ranger and while searching for powertrain options I came across a '97 Explorer locally for real cheap. I know the SOHC 4.0L's of that year only came with automatics behind them and I just can't bring myself to ever drive an auto, ever. I have a complete '92 wiring harness and EEC module for an OHV 4.0L and manual trans and for some reason I had this idea that this may work IF all of the OHV sensors and such are used with the SOHC mill.

Then again after typing that I am already seeing issues such as the fact that the OHV's rev limiter is set much lower than the redline of a SOHC, not to mention fuel curves and the like.

Maybe this is a stupid idea.

I should probably delete this thread before AllanD comes in and bitchslaps me back to reality, but I am curious just the same!

 

[Ranger44]

There is quite a big difference between the older OBD-I and the newer OBD-II management systems.

There's quite a bit of difference in the placement of sensors & added sensors, the upper intake manifolds are different(aluminum vs composite), and the wiring is routed a little different.

I know that they will swap into a 95' + Ranger without to much difficulty. But an older Ranger, It could be done, but the wiring would be an absolute nightmare.

 

[wahlstrom1]

I'll make it simple.....NO.


-andrew

 

[Sasquatch_Ryda]

Isn't the bellhousing bolt pattern different between the OHV and SOHC??

 

[Wicked_Sludge]

not that im aware of. the SOHC is still part of the cologne family.

i dont see why this wouldnt work. the SOHC is a pretty straightforward design. since the OHV doesnt use a distributor, all the sensors should be about the same between the two motors. i imagine you'll have to do some adapting here and there....and it certainly wont have the power and economy of a SOHC running on a proper SOHC tune (the fuel and timing curves must be radically different between the OHV and SOHC). youll probably have to use the SOHC MAFS and have it recalibrated so the OHV computer can work with the SOHC injectors.

but, why dont you just bolt a 5 speed to the SOHC and use the SOHCs computer?

 

[wahlstrom1]

Isn't the bellhousing bolt pattern different between the OHV and SOHC??

They have 1 bolt hole that's there on one, but not there other but I can't remeber which way it goes.....For all essential reasons, they are the same.

i dont see why this wouldnt work. the SOHC is a pretty straightforward design. since the OHV doesnt use a distributor, all the sensors should be about the same between the two motors.

He's trying to use an OBD I system to run an OBD II engine, not to mention where do you tie in 2 Cam position sensors etc? I'd just run the SOHC electronics like you mentioned and swap the whole deal in.

-andrew

 

[Wicked_Sludge]

the engine doesnt care if its OBD 1 or 2. the firing order is the same, the sensors are all the same (you'd only use one cam sensor for the EEC-IV electronics).

 

[BlackBII]

Doesn't the SOHC use two O2 sensors as well? Or I guess that wouldn't matter, as your using the OHV computer...

Sounds easier to just get a SOHC computer...

 

[turbo cat]

The ohv electronics will work I think theres a guy who has done this over at explorerforum. The early EEc IV EFI are not easily reprogrammable. It would be best using a 95+ obd 2 EEC V EFI as then you could use the SCT x cal PRP stuff to tune the ecu. It would be pretty easy as the motors ar identical just have different airflow requirments. But the firing order, bore, and stroke are the same and the motor bolts in like it is made t obe there of course. This will also give you sequential EFI rather than batch fire. The increase in economy would pay for the upgraded harness....

 

[Nipplechops]

The ohv electronics will work I think theres a guy who has done this over at explorerforum.

I think you are right. I'll have to resurrect my old account there and do a search.

The early EEc IV EFI are not easily reprogrammable. It would be best using a 95+ obd 2 EEC V EFI as then you could use the SCT x cal PRP stuff to tune the ecu. It would be pretty easy as the motors ar identical just have different airflow requirments. But the firing order, bore, and stroke are the same and the motor bolts in like it is made t obe there of course. This will also give you sequential EFI rather than batch fire. The increase in economy would pay for the upgraded harness....

The Explorer sold before I could get a hold of the guy. It was a mint 1997 with zero rust, only 195,000km and a smoked trans for 500 bucks. Looks like this idea won't be happening at this time. I still have a ton of work to do on this project, so I'll see what comes up.

Thanks for the replies!