4.0L OHV rebuild

[bajaman19]

Hi everyone. Im sorta new on here, I was on a while ago but lost my password and username. I just got it back up today. I just had a few quick questions about a 4.0L OHV engine im rebuilding. Ive done a little research on what to get to do the swap. I currently have a 99 Explorer Sport with the 4.0L SOHC engine. Im rebuilding an OHV engine out of a 95 explorer with only 110K miles on it with aftermarket pistons, rods, cam, pushrods, valves and valve springs(if I need them) and headers. I also want to get the engine bored .030 over and get head work done. Im rebuilding it because I believe the OHV models are more reliable than the SOHC models. I have the 5R55E trans with the auto 4x4 system, not sure about the transfer case model though. All I know about the t-case is that its a Borg-Warner t-case that is chain driven. I also have factory LSD with 4.10 gears. I go to an automotive tech school so I can get a little help with some things regarding this engine swap. But I figured the forum would help me the most. I have wiring diagrams for both engines to compare them to hopefully make this swap easier. I know that an OHV engine would bolt right up to my trans. I have also read a few other articles saying I will need an OHV ecm because of the difference between the fuel injection systems on the two different engines. Im assuming those are the two major things to be concerned about. Im pretty much rebuilding the entire engine including new sensors, egr valve and tube, and all OE parts such as water pump power steering pump pulleys and belt, and anything else it needs But if there are any other major concerns I would greatly appreciate any posts on this thread.

 

[2000StreetRod]

What about PATS?

One issue you haven't mentioned is PATS. If you replace your stock PCM with an OHV PCM from a model year before PATS was implemented that should eliminate the PATS issues but may introduce other problems such as the vehicle speed signal. In my 2000 the vehicle speed signal is generated by the 4WABS module. I think for some earlier model years the vehicle speed signal is generated by the PCM. That could impact your speedometer, cruise control, and a few other less important functions. If you plan to have a custom tune for your OHV, then you might consider using your existing SOHC V6 to control the OHV V6. Search the forum for SOHC to OHV engine swaps. I recall there is at least one that is fairly well described.

Edit: I just finished searching thru about 100 threads and didn't find any documented ones with a successful swap.

 

[bajaman19]

Thanks 2000StreetRod. Ill definitely have to do some research on that. I do know my explorer doesn't have 4WABS though.

 

[2000StreetRod]

4WABS module?

Are you sure that you don't have a four wheel anti-lock braking system (4WABS) module? I think all 1993 and later Explorer/Mountaineers have one. It was optional on the 1995 to 1999 Rangers. It should be located on the inner side of the driver side fender between the battery tray and the power brake master cylinder.

 

[bajaman19]

Im not to sure. Haven't had a chance to look. Ill take a look and reply as soon as I can.