4.0L OHV to SOHC conversion

[Scott B.]

The SOHC is much wider across the top. I thought about doing this to my '93, but I would have to rework/remove the heater box (I think that is what it is called) on the firewall.

From what I have read, wiring-wise, it is a very simple swap (at least for OBD-I trucks.)

 

[ZNathan130]

Why do you say I'll want the auto?

And I think I found a solution to part of my dilemma. My dad's work truck is an early 2000's Ranger and I believe it has the 4.0L SOHC. Not sure what transmission is on it. I recall at one point his boss replacing the transmission with something other than the stock. Not too sure though.

However, with just over 300k miles, I'd have to really think about if it would be worth it. In any case, I bet I could get it for cheap.

 

[ZNathan130]

The SOHC is much wider across the top. I thought about doing this to my '93, but I would have to rework/remove the heater box (I think that is what it is called) on the firewall.

From what I have read, wiring-wise, it is a very simple swap (at least for OBD-I trucks.)

I don't know if I'll have the problem since I'm a 2nd gen, but not too sure about that. If I do, I've got the most innovative people that could help solve it relatively quick.

 

[ZNathan130]

Does anyone know if I need to grab the wiring harness and/or computer from the SOHC donor?

 

[blueka]

I would... it wouldn't hurt...


Si

 

[ZNathan130]

That's what I and my brother-in-law(the brains of the operation) are thinking. I really need to go out and look at the info for my donor vehicle, but I'm pretty sure it doesn't have PATS. This would be a VERY good thing if I'm switching computers since mine doesn't have PATS either, right?

Also, I've never really done anything even close to this difficulty (hence the brother-in-law), so how difficult is changing out the computer and wiring harness ?

 

[blueka]

I changed my dash, which had a different wiring loom. but going from one to another should be ok as long as you get everything from one car, then you should be home free. get as much as you can and just swap it over..


Si

 

[ZNathan130]

I'll have the entire Ranger in working order, so I can grab whatever I need... just trying to figure out what all I'll need to grab.

I'll probably spend quite a bit of time from the time I put the Ranger down for donation and actually transplanting into my X. Plenty of time for a grade A rebuild!

 

[CARLITOX1]

The SOHC has 205 hp and the OHV has 160 hp ('95-'98 models cause my '99 OHV says in the prop manual it has 169 hp) so the difference are 45hp, but.. the SOHC has 9.7:1 compression ratio and OHV has 9:1. The diference is not only in the heads. if you're going to make that change, better rebuild your engine, use flat top piston (stock are dish) or lower the heads and raise the compression. Also to the OHV engine you can find a lot of camshafts. Comp cams has one for only like 280 USDs and for the SOHC, you have to go to Morana's site and pay 750 USDs for a couple of them. Also according to that site, the stock duration for the SOHC is .262 and for OHV is .256 (according to summit r). That's another difference, so you should think about how many ponys would really give you the SOHC and how much would you spend on it.
Remember also the OHV is giving you the top Hp and torque in lower rpm's than SOHC (better for street). Excuse my english, not my native language

 

[Neil1750825]

The SOHC has 205 hp and the OHV has 160 hp ('95-'98 models cause my '99 OHV says in the prop manual it has 169 hp) so the difference are 45hp, but.. the SOHC has 9.7:1 compression ratio and OHV has 9:1. The diference is not only in the heads. if you're going to make that change, better rebuild your engine, use flat top piston (stock are dish) or lower the heads and raise the compression. Also to the OHV engine you can find a lot of camshafts. Comp cams has one for only like 280 USDs and for the SOHC, you have to go to Morana's site and pay 750 USDs for a couple of them. Also according to that site, the stock duration for the SOHC is .262 and for OHV is .256 (according to summit r). That's another difference, so you should think about how many ponys would really give you the SOHC and how much would you spend on it.
Remember also the OHV is giving you the top Hp and torque in lower rpm's than SOHC (better for street). Excuse my english, not my native language

I agree with most of this. Basically, tune your OHV to what a worn our SOHC can deliver. Which isn't much more... Honestly a reflash and a cam would be pretty close by my estimation. No sense putting a worn out time bomb like an SOHC in your explorer. I prefer the SOHC because i have one but 300K is insanely high miles for one. You'd be lucky to get another 25K out of it. By the time you spend all the money and time updating it, you could have mowed a few lawns and saved up the cash to just tune the one you have. Thats my two cents anyway.

 

[hiltsy82]

I have a 2000 ford explorer 4.0l sohc guides are gone but i have a 1996 4.0l ohc will it fit or you have to change harness and tranny ?

 

[Neil1750825]

You'll need a 4speed tranny the 5speed only goes with the SOHC.

 

[Glen4X4]

You do not need to use the 4speed, 97+ the ohvs used the 5R55E. But as far as I know its not that hard, just change the wiring harness and possibility that one bolt hole will be off on the bellhousing at the top but all other holes bolt up fine.

 

[jelder]

There are alot of little things that you will need to change, like power steering lines, cooling lines, ac lines, thottle cable, trany dip stick, and maybe the y-pipe. I'm in the middle of a OHV to SOHC swap right now and I would never do it again unless I had a ready available doner. It really sucks when you have to buy parts or have them custom made

 

[Cobraguy]

There are alot of little things that you will need to change, like power steering lines, cooling lines, ac lines, thottle cable, trany dip stick, and maybe the y-pipe. I'm in the middle of a OHV to SOHC swap right now and I would never do it again unless I had a ready available doner. It really sucks when you have to buy parts or have them custom made

And it drives the price through the roof as well. I've done tons of swaps over the years...carb to EFI...engines, etc etc. I have never done one without a donor. Just too hard to find the little parts you need.

 

[snoranger]

There are alot of little things that you will need to change, like power steering lines, cooling lines, ac lines, thottle cable, trany dip stick, and maybe the y-pipe. I'm in the middle of a OHV to SOHC swap right now and I would never do it again unless I had a ready available doner. It really sucks when you have to buy parts or have them custom made

Thats why I got a donor when i did my OHV to SOHC swap.

The donor cost $500 and I sold off $700 worth of parts. I got paid to do my swap!!

 

[jelder]

I got lucky I found a doner to get most of the parts from the only problem is that its 70 miles away and its winter now and dam cold

 

[snoranger]

I got lucky I found a doner to get most of the parts from the only problem is that its 70 miles away and its winter now and dam cold

What? It was 60° today in NJ.:

 

[Backwoods "X"]

I remember reading somewhere that the SOHC motor could and would run on 1st gen 4.0 electronics. I need to go find that info again and share it. I can get a 62,000 mile 99 SOHC for $350 at the local yard, and since I need a motor for my Ranger now, this is a very interesting thing to look into.

 

[snoranger]

I remember reading somewhere that the SOHC motor could and would run on 1st gen 4.0 electronics. I need to go find that info again and share it. I can get a 62,000 mile 99 SOHC for $350 at the local yard, and since I need a motor for my Ranger now, this is a very interesting thing to look into.

Yeah, i kinda remember seeing that somewhere. Now where was it? Oh yeah, my engine compartment.