Is it a good Idea to Swap OHV to SOHC?

[Jstcruz]

I have a 97 XLT with the OHV 4.0 in it. I was thinking of buying another parts truck to swap the motor from so I can freshen it up without having my truck down for several days. But then I thaught about swapping in a SOHC 4.0 for power and milage reasons.

My questions are;
Would this be a direct bolt in or would I have to change the harness under the hood - or more?

Would I have to change my exhaust? - I am running only 1 inline cat with a 40 series Flowmaster and will be using headers.

And, were there any 2nd Gen Explorers with a good SOHC engine that isnt known for the timing chain issues? I want a 2nd gen 4 door so I can get several other parts from the parts truck.

Thanks in advance guys!
If it makes any difference, mine is 2wd automatic 5r55?.

 

[sport97]

Not sure about the exhaust but I know people have done the swap before. The timing chain issue wasn't fixed until the 3rd gen models so no luck there. What kind of mileage are you getting? Not sure its worth it for mileage, as you may see maybe 1-2mpg better. It is however a faster/more powerful engine, but with that being said my parents SOHC with 3.55 gears is not that fast. Mine with 4.10s however is much more enjoyable to drive. If you are going through the hassle of an engine swap go for the 5.0.

 

[snoranger]

I have a 97 XLT with the OHV 4.0 in it. I was thinking of buying another parts truck to swap the motor from so I can freshen it up without having my truck down for several days. But then I thaught about swapping in a SOHC 4.0 for power and milage reasons.

My questions are;
Would this be a direct bolt in or would I have to change the harness under the hood - or more? Harness is different.

Would I have to change my exhaust? - I am running only 1 inline cat with a 40 series Flowmaster and will be using headers. Y-pipe is different.

And, were there any 2nd Gen Explorers with a good SOHC engine that isnt known for the timing chain issues? I want a 2nd gen 4 door so I can get several other parts from the parts truck.

Thanks in advance guys!
If it makes any difference, mine is 2wd automatic 5r55?.

The SOHC timing chain issue was never really "fixed". Ford threw some band-aids at it, which made it better.... But they never truly fixed it.

 

[Jstcruz]

Not sure about the exhaust but I know people have done the swap before. The timing chain issue wasn't fixed until the 3rd gen models so no luck there. What kind of mileage are you getting? Not sure its worth it for mileage, as you may see maybe 1-2mpg better. It is however a faster/more powerful engine, but with that being said my parents SOHC with 3.55 gears is not that fast. Mine with 4.10s however is much more enjoyable to drive. If you are going through the hassle of an engine swap go for the 5.0.

I was waiting for a 5.0 remark! If I wanted a 5.0 I would get one. I am interested in better milage from what I get out of my very capable 4.0. I am getting about 18 mpg and saw Aldive was in the 30s with his SOHC. I know he had several other mods but I dont want to keep modding mine for milage if the other engine has a higher rating to start with. Im going to try to stick with my 3:73 axel, from what I understand is better for highway milage - could be wrong on that cuz Im easily confused about the ratios lol.

 

[Jstcruz]

The SOHC timing chain issue was never really "fixed". Ford threw some band-aids at it, which made it better.... But they never truly fixed it.

With that being said, are there any upgrade parts I could put in there to make it last longer? Also, I dont pound on my truck very much - no offroading or racing but I like to get on it once in a while to pass ppl or get out of ppls way. I just really dont want to have to listen to the death rattle shortly after doing all the work - if I do it.

 

[snoranger]

I am getting about 18 mpg and saw Aldive was in the 30s with his SOHC. I know he had several other mods but I dont want to keep modding mine for milage if the other engine has a higher rating to start with.

Al had a lot more then "several other mods". His biggest fuel saver was his driving style.


You wont gain any noticeable mileage increase with a SOHC swap. I didnt.


Personally, if I build another v6 RBV, I'll build a mild OHV.

 

[Jstcruz]

Al had a lot more then "several other mods". His biggest fuel saver was his driving style.


You wont gain any noticeable mileage increase with a SOHC swap. I didnt.


Personally, if I build another v6 RBV, I'll build a mild OHV.

If you have 1st hand experiance at it then I'll take your word for it. And I know the importance of driving style to save gas.
Thanks for your input. Now, hopefully I can find a parts truck with a decent OHV in it!

Thanks for the replies guys!

I am still open to further input for the sake of learning! And so other ppl may not have to search for hours on this particular subject like I did

 

[slickemhoundd]

Only input i have after having 2 sohc and my present ohv.... the soch is much peppier but much less reliable, at least with my experience. Im only at 158k on the ohv now and did nothing to it but intake gaskets and o2's. My 2 soch with didnt even make it to 140k before i was working on it more than i drovem. Just another idea... my buddies 94 navajo is pushing 476k and i swear his runs better than mine, granted hes on his 5th trans but never did anything other than basic maintenance and replace accessories when need be.

 

[FIND]

Al also had a 2wd, which makes a huge difference.

Just go 5.0. They get the same mileage with AWD as a 4wd 4.0. Go with the F150 4wd transfer case when you do the swap and throw on some TMs and you should see 21-23

 

[vroomzoomboom]

here's my 2 cents. 5L swap, you have to change more then the motor. if you dont have a donor, you will be chasing parts. going to a SOHC, for one of your questions, you will have to change the exhaust. it had 3 cats, and if i am not wrong, a OHV has two. i dont think you would have to change the wiring under the hood, but you would have to use the motor harness, and maybe the computer. mileage, i think you would get 1 or 2 less then a OHV. my SOHC wasnt great on fuel. SOHC's have more grunt then a OHV, but a OHV is way more reliable. as well, if you do have a problem, a OHV is a ton easier to work on vs a OHV. i look at a OHV as being a old school motor, and a SOHC as one of those motors that you have to have the new expensive tools to work on.
thats me however.

 

[FPGT24]

I was waiting for a 5.0 remark! If I wanted a 5.0 I would get one. I am interested in better milage from what I get out of my very capable 4.0.

I hate 5.0 Explorers. I've had 2 and i hated them. I will stick to the OHV and SOHC. I hate it when i get the "should've got the 5.0!" remarks when my SOHC's give me issues....

 

[FPGT24]

NO. do not swap it out to SOHC! the OHV is 3x more reliable and will last 100k+ more miles than a SOHC. only bad thing is horrid fuel economy and gutless. I love both of them though but I have a lead foot i need SOHC.

 

[R1dd1cK]

Well you all must be hard on your SOHC motor or some thing. My SOHC motor had almost 250,000 miles on it before it started to rattle from the chains.

 

[Flash]

A guy came on the forum recently told us how he got 425,000 miles out of his SOHC.

are there any upgrade parts I could put in there to make it last longer?

Hell yeah! Get a better quality aftermarket timing chain set, guides and tensioners, that's most of the problem fixed right there.
If you really want to keep it forever install a pre oiler so you never get the "start up rattle" which shakes the crap out of the original guides.
It will also save the rest of your top end and bearings.

Then get a bypass filter and regular oil changes and the thing will be nearly indestructible

OHC lovers will say "why do all that?" If you do all that you'll have fixed the one weakness in the engine, have better power and economy than an OHC and it will last' and it won't cost all that much.

 

[masospaghetti]

I would keep the OHV - reading about the timing guide issues sounds like a nightmare waiting to happen. The SOHC engine was a poorly designed motor.

The OHV, while not that powerful, is very reliable. It also has better EPA fuel economy ratings than the SOHC (despite what people say about it - 18/23 vs 17/22 with the 5-speed) so I don't think switching would gain you any appreciable fuel economy.

 

[snoranger]

As I've said before...
In normal driving conditions, you really wont see much, if any difference between the OHV and the SOHC. If your constantly buzzing the motor above 3k, then yes, the SOHC is the engine to have. BUT... The guides dont last as long if your always beating on the motor. Its a catch 22.