What 4.0 OHV Heads are quality for a stock build? | Ford Explorer Forums - Serious Explorations

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What 4.0 OHV Heads are quality for a stock build?

Kirby N.

Elite Explorer
Joined
February 6, 2001
Messages
2,601
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412
City, State
Colorado Springs, CO
Year, Model & Trim Level
1991 Ranger
Hey everyone-

I am looking for some advice. My 1991 Ranger 4.0 has 315k on it. Still running strong, but I drive it everyday and I want to put a rebuilt engine in it.

I am looking for reliability NOT performance. I am also not looking for a bargain, I want quality. If I could buy a crate 4.0 ohv from ford that would be ideal. But I can't. I got a 1998-2000 motorcraft rebuilt short block. which means it has late model pistons in it. I dont want to redo anything in the stock wiring and I want to run all the stock accessories.

What heads would you get and from where? should I swap to early pistons?

Here is the truck it is going into:

IMG_0693.jpeg

Thanks in advance.
 



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I have always heard good things about the world product heads for these engines. Have you priced them?

New short block! Wicked cool… that’s the one part of the ohv that will last outlast the truck if taken care of

Why change pistons? ( just run the later “clean fire” heads)
 






ive heard about clearwatwr ___ heads (mot clearwater revival ;) )(forgot the second word) from brian1 iirc! i dont have an ohv, so cant speak to anything but what ive heard!

edit: its called clearwater cylinder head, apoken of in this link Cylinder Head vendors
 






I have always heard good things about the world product heads for these engines. Have you priced them?

New short block! Wicked cool… that’s the one part of the ohv that will last outlast the truck if taken care of

Why change pistons? ( just run the later “clean fire” heads)
I haven't I will look into it. Yeah- Its a motorcraft rebuilt NOS short block. A guy on craigslist had it in a crate in his garage for years. So I guess it isn't NOS- its rebuilt old stock, but it is rotorcraft.

I have heard from a couple that if I use the 98 heads I will be fine- trying to get more to weigh in on that- but it is where I am leaning now. Your opinion carries a ton of weight with me- so if that's what you think I should do I am all over it.
 






ive heard about clearwatwr ___ heads (mot clearwater revival ;) )(forgot the second word) from brian1 iirc! i dont have an ohv, so cant speak to anything but what ive heard!

edit: its called clearwater cylinder head, apoken of in this link Cylinder Head vendors
Thanks for the link- it seems someone found some NOS Motorcraft heads on eBay. If that is the case I will consider those. I like factory parts.
 






Thanks for the link- it seems someone found some NOS Motorcraft heads on eBay. If that is the case I will consider those. I like factory parts.
not an ohv guru, but do they make updated units to fix the factory cracking flaw?
 






Oh man a whole factory crate ohv is like gold!

I’m usually on a huge budget because so much is being spent on the rest of the truck so we do not normally get into engine rebuilds or crates here, we try to source the latest model and lowest mile engine we can for the best price. Getting harder to do w a ohv. Eventually we will have to “rebuild” all of these core engines I’m holding onto

The last of the ohv 98-2000 were simply awesome they just go and go
Heat and dirty oil are of course the enemies
 






yes, but from what I understand- and what is confirmed in that thread- is that the cracks are not an issue in the later heads. Heck my 91 went 315K without a crack!
 






yes, but from what I understand- and what is confirmed in that thread- is that the cracks are not an issue in the later heads. Heck my 91 went 315K without a crack!
whoops, my bad ;) forgot what it was that cracked on the ohvs
 






Oh man a whole factory crate ohv is like gold!

I’m usually on a huge budget because so much is being spent on the rest of the truck so we do not normally get into engine rebuilds or crates here, we try to source the latest model and lowest mile engine we can for the best price. Getting harder to do w a ohv. Eventually we will have to “rebuild” all of these core engines I’m holding onto

The last of the ohv 98-2000 were simply awesome they just go and go
Heat and dirty oil are of course the enemies
I paid $500 for it- bought it about 4 years ago. Do you think my OBD1 would be happy if I use 98 heads and pistons and all the other dress of a 91?
 






The ohv heads were upgraded 3 times from the factory
The “cracking” or head gasket seal issues are usually from heat…like waterpump failing and they keep driving or from sheer lack of maintenance
They easily last 150-200k miles from the factory with just basic oil changes, these are tough engines! The early ones 1990-94 had the weakest heads, in 95 big upgrade and then again in 97-98 I believe
A factory engine that goes 200k on average is not a flawed engine
With age abs with ethenol added to our fuel gaskets and seals need replacing. If you don’t…. Engine failure is eminent
Same is true with any engine produced in fords from the 90’s, especially the 7.3 international power stroke holy Moley there is a spreadsheet for all the o ring sizes on that engine. They stripped the sulfur from the diesel fuels and the o rings from the 80-90 were not designed for that. Update the gaskets abs Re seal the leak prone areas abs you can see 500+ k miles from the pushrod 4.0, 5.0 or my favorite the 7.3 diesel lol
 






I had a 98 engine in my bii with a 93 pcm for about 5 years yes I think your pcm will be fine. Also I ran 85 octane only, being in Colorado you do not suffer from the same combustion issues the lower elevations do… ohv run goooooood in the mountains

If you take that ranger to sea level for some wheeling you may just need to up your octane to help with any detonation… but I doubt it. My 4.0 powered bii lived in laguna Nigel (just north of sandiego) for like 2 years, no problems

Pcm does what? Controls air fuel spark by collecting data from sensors, it can adjust for changes in altitude from below sea level to 14’000 it can adjust for 85 octane ip to 93 or higher, it can adjust for up to 6 psi of boost…. I think your late model longblock with an early pcm is just fine…..
I replaced several early ohv with the 95tm+ engines over the years, I never heard of any issues with using the clean fire stuff? Maybe I’m just lucky :) being at 5280-9000 most of my
Life didn’t hurt.
I can also tell you Brett is running a 04 sohc in his 94 sport using the 94 pcm ;)
Seems the pcm is pretty capable of adapting

I’m going to do some research about issues with running the later engine with early pcm now… let’s see what others have experienced. I will share my findings ;)
 






Oh one more thing!!

Why not seriously update that ranger and run a 95-00 pcm? Obd2 conversion!!!

They are way better computers
My 88 thinks it’s a 97 100%
I love having an obd2 port and eec-v pcm
The 95-97 ranger 4.0 pcm is nice I think some years no egr

I am sure I have bugged you about this before hahahahaha! Just like everytime I work on my ttb I think about you “just rip all that out and solid axle that thing already” and I have a good laugh!!

I love your ranger very much. I know I enjoy driving my 88 almost every day. If I’m lucky I might score a $150 87 extended cab this weekend no title…u
I’m trying to collect as many rg trucks as I can! Finally in a place in life where I can park some in the back 40 lol
 






I’m trying to collect as many rg trucks as I can! Finally in a place in life where I can park some in the back 40 lol
wish i had the space ;) if i did i'd probably have a ranger, 1st gen etc etc by now... then again maybe its better!!! keeps the insanity "minimal"🤣
 






I had a 98 engine in my bii with a 93 pcm for about 5 years yes I think your pcm will be fine. Also I ran 85 octane only, being in Colorado you do not suffer from the same combustion issues the lower elevations do… ohv run goooooood in the mountains

If you take that ranger to sea level for some wheeling you may just need to up your octane to help with any detonation… but I doubt it. My 4.0 powered bii lived in laguna Nigel (just north of sandiego) for like 2 years, no problems

Pcm does what? Controls air fuel spark by collecting data from sensors, it can adjust for changes in altitude from below sea level to 14’000 it can adjust for 85 octane ip to 93 or higher, it can adjust for up to 6 psi of boost…. I think your late model longblock with an early pcm is just fine…..
I replaced several early ohv with the 95tm+ engines over the years, I never heard of any issues with using the clean fire stuff? Maybe I’m just lucky :) being at 5280-9000 most of my
Life didn’t hurt.
I can also tell you Brett is running a 04 sohc in his 94 sport using the 94 pcm ;)
Seems the pcm is pretty capable of adapting

I’m going to do some research about issues with running the later engine with early pcm now… let’s see what others have experienced. I will share my findings ;)
Excellent thank you. That’s what I needed to hear. Yes we have had the obd2 convo many times. You forget I am a sissy when it comes to wiring!

Will I need to or should I swap exhaust manifolds for late 4.0?
 






I would put some headers on that bad boy

I don’t think the later
Model ifs manifold will fit your ttb truck? Something in my brains says the passenger side is different between the two

Consider getting some 4.0 headers for a ttb truck should work w your 91 style y pipe

I just happen to be converting a 89 ranger to a 96 ranger 4.0 right now
I will be detailing the wiring I have done too
You could copy me
It’s a 89 ranger with a 96 4.0 and 5 speed, kid and his grandpa built and got over there head with the plumbing and wiring. I’m almost finished with the obd2 conversion.
 






I actually just posted a question on OHV heads on the stock side, found a great deal on OEM Ford 93TM heads on Ebay and since mines not a daily drive, has an upgraded cooling system I'm going to just run those. As a Ford technician for over 33+ years I've seen some cracked heads over the years, but it's never really been a huge issue my old 93' Explorer is still going strong on the original long block at well over 300,00 miles.
 






I saw that. I messaged the guy and he said they are in fact nos ford units- but he doesn’t have any 98tm
 






I have a set of 98tm aftermarket heads I'm never going to use, new in the box, never opened.
 



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brand? Let’s make a deal!
 






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