OHV to SOHC

[matt32]

Iv searched to the tech library already...but my question still needs an answer. What do i need to consider when swapping in a new '01-03 4.0L SOHC motor out of a ranger into a 97 ranger with a 4.0L. Im assuming it should bolt up up to my 97's 5 speed if the '01-'03 was a 5speed right??

Will the wiring be any different? or just swap computers?

motor mounts same??

thanks in advance, matt

 

[Bird]

A very easy swap - get the engine harness, PCM, intake, TB, injectors and fuel rails from a 97 Explorer that came with the SOHC and you'll be able to virtually drop it right in - tranny will bolt up with the exception of the bolt at the top right. You can use the motor mounts from OHV with no problems.

Bird

 

[hiwy101]

from what i have read and such, the SOHC block Engine mounting points are the same. The transmission pattern is the same except for one bolt which is in a different place. Off hand i cant remeber which one. I have worked on a friends 4.0 SOHC Explorer and the heads are pretty big compared to OHV 4.0. so you might have trouble if you have 97 AC, but i think the 97 body has more room but im not certian of this. I know the AC unit changed From 95 on.

As for computers and wiring, you will need the wiring and computer and the PATS stuff from the 01-03 SOHC to get it to work with 97. I believe, Not sure but i dont think 97 ranger was PATS (Passive Anti-Theft System) equipted. It is likely if you need PATS that the dash wiring may need to be replaced to support it. but i have never changed pats but i know it can be an issue.

Also, keep in mind the power sterring on the SOHC is totally Different than 97 4.0 OHV PS. As well as the AC compressor setup. You would need the PS/AC brackets pump/compressor etc... Be sure to get the alternator brackets also. I think you can use the alternator from the ranger though because i've put 1994 ranger alternators on a 2001 SOHC Explorer Engine. I had to put the white/black stripe jumper wire from terminal #2 to the single terminal next to it from the 1994 connector. as well as use two bolts instead of three, two seem to hold just fine. I know the alternators were the same from 92-97 on rangers. Hope this answers alll your questions.

 

[matt32]

alright that pretty much answers everything! thanks guys

 

[Bird]

As for computers and wiring, you will need the wiring and computer and the PATS stuff from the 01-03 SOHC to get it to work with 97. I believe, Not sure but i dont think 97 ranger was PATS (Passive Anti-Theft System) equipted. It is likely if you need PATS that the dash wiring may need to be replaced to support it. but i have never changed pats but i know it can be an issue.

There's no need at all to try to cobble together the wiring harness from an 01-03 Ranger - the 97 Explorer SOHC engine harness would drop right in and hook up to existing connectors in the truck - not require any rewiring of the dash or rest of the truck. No use making this more difficult. Any AC hoses / ps components could come from the donor 97 SOHC Explorer as well.

Take a look at my sig - how do you think I swapped in my SOHC ??

Bird

 

[hiwy101]

LOL your right bird, i had forgotten that explorers in 97 had SOHC without PATS. My Bad, LOL!!! Yea that makes it really easy.....sounds like a fun swap, id drive it lol. Good luck Matt! Let us know how it goes when its done!

 

[exbass94]

You can get the wiring from a 97 Explorer, but I wouldn't use an engine from a 97. They had significant problems with the timing chain tensioners in the beginning, and all the bugs weren't worked out till around 2001.

 

[matt32]

the only reason i wanted to go to the SOHC was because there is more hp & tq. i know they put those starting ni 01 for rangers, but did the 97 explorer SOHC have more hp and tq than the stock 4.0L 97 ranger did??

 

[matt32]

You can get the wiring from a 97 Explorer, but I wouldn't use an engine from a 97. They had significant problems with the timing chain tensioners in the beginning, and all the bugs weren't worked out till around 2001.

what kind of issues, anything i should be worried about??

 

[hiwy101]

The numbers i have seen only vary slightly in HP and Torque over the years of 4.0 SHOC. But always it was significantly higher than the OHV 4.0. Remeber that you have to rev a 4.0 SOHC MORE to get the power. The power band is a bit higher. just something to think about. I like torque on the low end.

I have also heard intially the chain tensioners were a bad design, I think it took until about 2001 to fix it, i have a friend with a 2000 ranger and i can hear the timing chain when it idles. Not a good thing, it only has 125,000 Miles. I have never touched a 4.0 SOHC Timing chain or heads. so i have no experience as to what to look for besides the timing chain guides. I'm sure someone else on here has more experience. there may even be better replacement parts avalible now. I am not sure...You should look into that as well. Just so you know.

 

[matt32]

cool, thanks hiwy101, that makes sense you gotta rev the SOHC higher, i also kinda like the low end torque the OHV 4.0L puts out...gotta do some thinkin.

it will eventually have the lift off my old truck and will be runnin 33's...so maybe ill just keep the stock engine and save the hassle and re-gear my axles to get back some of the lost torque

 

[Bird]

Hey hiwy101 - where do you get your data from ? Here's the 'official' numbers from Ford:

except for a slight loss below 1500 rpm, the sohc is vastly more powerful all the way throughout the rpm range.

Bird

 

[matt32]

damn...maybe i will do the swap

 

[Big Jim M]

I don't know bout you guys but my sohc rarely sees 3,000 or more rpm's.. So according to the chart above what I am using of the sohc is no better, not much anyway, than the older ohv. I am quite happy with the preformance of the sohc below 3,000. I can't imagine using the engine all the way to five grand..
Big Jim

 

[Warpath]

Not trying to hijack a thread, I have a 94 Ranger 4x4 with the 4.0l ohv w/ 302,000. I getting a little nervous and would like to install a 4.0 sohc. Since my ranger is a little older than his 97' and runs obd I, what would i need differntly to do the conversion??

Thanks,
Jim