souping up the OHV 4.0

http://www.youtube.com/watch?v=tFNwvj0Ifs0 seen this guy had a perty bad little 4.0 i was wondering you think it would be easier and cheaper to fix up a 4.0 ohv thats in my ranger or get a 4.0 sohc and fix that up? any ideas on what it would cost to get around the 300hp mark?

Nope!

91rangerxlt said:

http://www.youtube.com/watch?v=tFNwvj0Ifs0 seen this guy had a perty bad little 4.0 i was wondering you think it would be easier and cheaper to fix up a 4.0 ohv thats in my ranger or get a 4.0 sohc and fix that up? any ideas on what it would cost to get around the 300hp mark?

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THINK V-8! Why go to the trouble and expense with the smaller engine.. You want power? Go V-8...
Big JIm

^^^ exactly do a little searching and you will find your answer. you can swap in a 302 and make 400hp for what it would cost to make 250 at the wheels out of a 4.0

So before you get any specific recommendations I've gotta ask:

What do you do with the truck NOW?
What do you want to do that you cannot with the torque/power
you have now?

what doesn't it do that you want it to do?

Some things are just beyond practical reach....

Some people have unrealistic expectations or goals, and I like to know if I'm speaking to one of them before I waste my time explaining reality to them.

Any "Improvement" comes at a price...

There is an old saying that "engineering is choosing what compromises to make".

In the case of the 4.0 the "compromise" was over the design of the engine as an "improved" 2.9 and was accomplished by adding
displacement to gain the torque characteristics that were needed
to do the job and taking the penalty in econonmy.

I can say that running "unladen" the 4.0 does tend to eat a bit more fuel than a 2.9 in an identical truck... I can actually say "Identical truck", because I swapped a 1993 4.0 into my 1987 Ranger.

I can also say that loaded or towing the 4.0 isn't as stressed and I get BETTER mileage with the 4.0 than I could with the 2.9 towing similar loads.

Yes, that's right bigger engine BETTER mileage while towing!
that's mostly because the 2.9 needed to be "Flat out" a good
portion of the time, the 4.0 does nearly "effortlessly" what
really shouldn't be tried with a 2.9.

Like last July I towed another Ranger (1 1992 3.0 2wd Long-box)
from Southbend IN, to where I live in PA, total Mileage? a bit over 660miles. I managed nearly 16mpg while TOWING another Ranger. I had no difficulty maintaining 65mph on any hill and there were only two or three hills that made me shift out of 5th, and NONE that got me out of 4th and into 3rd, not only that I could effortlessly "walk away" from my chase vehicle... a 1991 2.3/5sp/2wd Ranger shortbox being driven by the owner of the truck I was towing

So I tend to find difficulty in understand what exactly is "broke" with a 4.0OHV that some people feel a need to "fix"...

Generally speaking if you want more acceleration you want gears.

your 1996 could be saddled with 3.27's or 3.55's... when what
you probably want are 3.73's

IF you really want a 4.0 to make more power that power is going to come at a price. USUALLY increasing power is done by changing the cam timing and spinning the engine faster, the engine can only make torque in proportion to it's displacement, so while you will get more power, you effectively ruin the
low rpm performance.

IF you want your cake and get to eat it too there is a way out: Blower.

blowers don't make more "power" except by accident.
what they do is force more air into the engine and that makes more torque, if more torque happens to make more power that is a secondary effect...

But Torque is at the route of it all.

Increasing compression can make more power without adversely
affecting low rpm performance, but is expensive and requires premium fuel...

Finding out why you think it needs improvement whil help choose what method to improve it.

Frankly I think most people with 4.0 trucks just need to be forced to drive an identical truck with a 3.0 for a months to return them to reality...

that reality is: "It's a Ford, not a Ferrari".

AD

That has GOT to be one of the most intellegent answers I've read in a while.

Fast Doc said:

That has GOT to be one of the most intellegent answers I've read in a while.

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+1 <<<<<

Some people have unrealistic expectations or goals, and I like to know if I'm speaking to one of them before I waste my time explaining reality to them. +1

good response

If you're looking for a street racing v6 ranger that you can go around saying "hey, i just picked off your v-8 mustang with my v6 truck ranger" you're looking atleast at 3.k+


and ALOT of time. I have a set of ported heads and intake sitting in my dads garage that i just paid 1.7 for together and i probably won't get 80hp out of it off the engine, and probably just under 45 at the wheels

Give you an example of how much you can expect to pay. I rebuilt a 4.0 over the summer. new everything except kept crank, heads pistons rods. with cleaning up the rest. new bearings, seals, gaskets, (your main rebuild stuff) added 410 cam... sitting now dollars invested including new belt hoses oils .... $2,000. and this is just for a rebuilt motor. nothing over the top nor added bolt on. stock exhaust.

Hi allan, hope you don't mind but i had to use your quotes here.... well said!!

AllanD said:

Generally speaking if you want more acceleration you want gears.

your 1996 could be saddled with 3.27's or 3.55's... when what
you probably want are 3.73's


AD

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ive got 3.73s in it right now i read your whole reply and yea it makes since, but im one of those guys that like to pull up to a stoplight right beside a nice camaro or mustang and blow their doors off. im looking to kind of turn it into a sleeper was the plans. i could go with a 5.0 swap but i want something im gonna beable to bolt right up to the tranny thats in it now.

u guys think it woulf be easier to pick up an old junker and do a 5.0 or 351 swap???

Angie said:

+1 <<<<<

Some people have unrealistic expectations or goals, and I like to know if I'm speaking to one of them before I waste my time explaining reality to them. +1

good response

Click to expand...

+1

What Allan says applies to MOST performance mods, don't throw your money away!!!

91rangerxlt said:

ive got 3.73s in it right now i read your whole reply and yea it makes since, but im one of those guys that like to pull up to a stoplight right beside a nice camaro or mustang and blow their doors off. im looking to kind of turn it into a sleeper was the plans. i could go with a 5.0 swap but i want something im gonna beable to bolt right up to the tranny thats in it now.

Click to expand...

Then I have a suggestion for you, first install the grabbiest gears you can stand to live with on the highway on a long trip.

a 4.0 will get it's best highway mileage at ~2250rpm

then? Go shopping for a Nitrous Oxide system and a spare
engine for when you push it "too far".

If I were bottle feeding an engine to play traffic light bingo
I'd pick something cheap and replaceable that I can get cheap
junkyard replacements for.

That and an AAA membership to get you towed home when
you grenade it and you are golden.

Yeah, you can turd polish every part of the engine to make it
work better with nitrous...

About as far as I'd go in "optimizing" a 4.0 for bottle feeding
it would be to put TM93 heads on a 99-01 short block.
This would lower compression a bit (allowing a bigger shot)
and the later bottom end vibrationally "stable" to 6000rpm.
The early six bolt crank 4.0 isn't.

I'm from a group of "old timers" who with humor and a large
dollop of truth refer to Nitrous as "supercharger in a bottle"
which in essence is EXACTLY what it is.

I'm not sure if someone GAVE me a new, old stock Ford Motorsport
Paxton Kit for a 4.0 if I'd actually put it on my truck (who am I kidding?
Hell yes I would!) but I'd install Nitrous FAR faster.

Personally I'd love to have about a 50-60hp shot, but I'd be just a bit cautious I'd use two rev control switches, one to trigger the system
on at 2250rpm and turn it back off at 4000rpm.

BTW, if your truck is a 5sp? spring the $219 Summit wants
for a Hurst Billet plus shifter a quick accurate shift is worth
quite a bit.

AD

To the OP, i find it amazingly hilarious that a lot of the information you have/will recieve on this subject will come from people that have little / none knowledge of the internals of the 4.0 and the possibilities of modifications - they're standard answer will be "change the gears - there's nothing else that you can really do". While that will work in some instances, it's not the 'do all / be all' for your wants.

The stock 4.0 OHV is, in actuality, a very stout engine and capable of taking a lot of abuse with regular maintenance and keeping the cooling system fully operational. I have personally put well over 200 1/4 mile passes on a stock motor with 6 lbs of boost from a supercharger system and it survived beautifully - compression was still up in the 170's on every cylinder before I swapped it out and it ran smoothly and quietly. That engine is now in another Ranger and still going strong after 50k more miles since the swap. The cranks and rods in these engines are quite good and the factory cast pistons, with the exception of the 98-2000 series) are strong enough for moderate boost or nitrous as long as detonation doesn't rear it's ugly head (easily controlled with timing changes). The intake ports actually flow quite well, but the exhaust side of things is where the restrictions lie - a lousy bowl and short side radius along with low port roof really choke it down - combine that with the log exhaust manifolds and you've got flow problems. In the 98-2000 heads, Ford really hurt the flow with even smaller ports for emissions purposes. Headers really do help in this area - removing the manifold restriction and helping scavenge out some additional exhaust gasses. That's about the only worthwhile mod that you can do to a 'stock' engine that will show any real 'gains' in power - intakes, MAF's, etc are a waste of money at this point.

Now for the 'good' part - internally, the factory cam is a piece of crap - the 410 cam is what should have been installed from the factory - good lift and moderate duration on this cam gives great low rpm drivability and a nice bump in higher rpm flow - just requires proper setup with correct length pushrods.
The exhaust ports in the heads really need a good port job and replacing the valves with one piece, undercut stem stainless valves will wake these up. You can get an honest 45+ rwhp gain from heads / cam / headers.

Now, is all this worth it....................NOPE !!!

These engines aren't like the small block Fords or Chevies that have thousands of cheap parts available - everything that will honestly give power on these 4.0's is practically custom (= big $$$$). I've only done it because I have my own flow bench and do my own porting / polishing and get the rest of my parts at jobber prices or through scrouging good deals on used pieces and do all of my own mechanical work. Wouldn't do it if it cost me what it would normally cost anyone else - especially good port work (notice I said 'good' - any Joe Blow can hog out metal for cheap and call it a port job, but you get what you pay for - especially with these heads). There's also the additional cost of retuning the PCM to maximize the gains with these parts - either buying the software package or paying someone else to do it = $$$$$ - again, i do my own on multiple vehicles thereby spreading the cost.

I do disagree with AD about dropping the compression to run nitrous - that's a full point compression drop - 'NAWZ' likes compression and there's a very simple way to drop the timing necessary for a 60 shot. Why drop compression and hurt everyday drivability and power? It's a good alternative for short requirements for additional power.

If you can find a decent supercharger system that was available for these engines at a good price, that would be the best bang for the buck for all-around drivability and power - otherwise, swap in the V-8.

If all that is beyond your means or capabilities, change the gears, maybe add some headers and be happy.

Bird

ps. the SOHC is a stronger engine, but will involve a lot of work to swap over properly and cost even more that the OHV for power mods.

Hey Bird. In regards to what you said here ...

"There's also the additional cost of retuning the PCM to maximize the gains with these parts - either buying the software package or paying someone else to do it = $$$$$ - again, i do my own on multiple vehicles thereby spreading the cost."

Can you go into more detail about how to tune this area? For this could be the information I was looking for about my build. As you are aware from a different thread I was/am having that small problem, and after the injector swap tings have mellowed out for the rich burning, however, i still feel that she isn't running 100% yet. any knowledge on this fine tuning will be appreciated. (links??)

thanks