2.9L to early 4.0L swap really worth it?

I was reading in the technical information and noticed that the horsepower ratings for the two motors aren't very different. I was just wondering if the swap is really worth all the trouble. Thought I would start this to see what everyone thinks. I have an 88 Ranger 2.9 and have the option to get an early Explorer with 4.0. Thank you.

The difference between the 2.9 and the 4.0 is rar, FAR more than it would appear in the published Horsepower specs of the two engines...

First off while 20hp isn't all that much of a difference the difference in torque is actually quite profound... the 2.9 makes 170ft/lb@2600rpm and while toe torque spec varies between 2400rpm(Aerostar) and 3000rpm for various calibrations of the 4.0OHV the torque specs are 220ft/lb, 225ft/lb or 230ft/lb(Aerostar)

Ponder this a moment, 225ft/lb Vs 170ft/lb, that's a 32% increase in torque.... But even that doesn't tell the entire picture... because the 4.0 produces significant useful torque well below it's torque peak.

While the 2.9 kinda falls flat below 2300-2400rpm the 4.0 is still making torque in the 1600-1800rpm range.

Yeah, if the 4.0 made the same power at higher rpm like the 2.9 does it'd make ~195hp but that isn't where you really use the power, or even need it....

Now if you do like I did and switch from a 2.9 to a 4.0 with headers (Borla) you'll really like the 4.0...

To me with the headersit does seem to make bit more power up high, and more torque through the entire power band.
I'd even venture to say that the 4.0 (with headers) makes more torque at 1800rpm than the 2.9 makes total

Borla used to advertise that their headers added 35hp and 50ft/lb of torque and after driving my truck I have little trouble believing it.

I only finished the conversion in the last few weeks and have accumulated 78miles test driving and 1800miles and change driving it home from wyoming

It was flat-towed out there as my ride home after "ferrying" an F-250 out there.

Yeah, I was pretty sure everything was "right".

It wasn't the first time (or the second or even the third) that I have assembled a vehicle from parts (or a major repair) and hopped in it and driven 1000 (or more) miles without a second thought.... (well, not entirely without second thoughts, but...)

I'm still chasing an annoying problem with an uncooperative A/C-WOT cutout relay (It trips out and never re-connects) and I just found a loose ground that caused the headlights to blink out intermittently (striped thread), but the engine, MASSIVE changes to the entire vehicle wiring (converted an '87 Ranger to a '93 explorer's power distribution system) as well as actually finishing the installation of my factory dual tank system (but not actually using either of the factory tanks or fuel pump installations)

And finally I rewired the lighting so that the headlight and multifunction switch do not actually switch the rear brake and turn signals or tail lights. as I added an additional relay box under the hood so that the relays actually switch on the rear lamps, I also added a set of diode isolators so that I could control those lights from the vehicle I towed my ranger with, which is actually pretty slick...


AllanD

No....not really.

Put some 4.10's behind that 2.9L....and you wont miss a 4.0L at all.

Some agree the 2.9L was very underrated from the factory.

later,
Dustin

Ahhhh the great 2.9vs4.0 ensues again.... I have 4.10s behind my 2.9, its not enough, get a 4.0... A 32% increase in torque doesn't lie Dustin...

Ive drivin them both....for an extra liter in displacement, and the extra fuel, and the work of swapping them over, the extra 1\4 sec you save to 60 isnt worth it.

A 2.9L will jump a 4.0L till about 25 anyways.

later,
Dustin

rusty ol ranger said:

Ive drivin them both....for an extra liter in displacement, and the extra fuel, and the work of swapping them over, the extra 1\4 sec you save to 60 isnt worth it.

A 2.9L will jump a 4.0L till about 25 anyways.

later,
Dustin

Click to expand...

If you tow it will be worth it however, that 55 ft lb of difference in torque will shine in that arena.

Afterall if a somewhat peakier 2.9 170 lb-ft will out tow a 4.0 smooth 225 ft-lbs, then my really peaky 2.8 with 143 will whoop them both.

rusty ol ranger said:

Ive drivin them both....for an extra liter in displacement, and the extra fuel, and the work of swapping them over, the extra 1\4 sec you save to 60 isnt worth it.

A 2.9L will jump a 4.0L till about 25 anyways.

later,
Dustin

Click to expand...

Were both rigs you drove equipped the same? Same tranny, gears, tires, bed, cab and 4x4 or 4x2? I average 15 mpg with my 2.9, doesn't matter how I drive it... I'm POSITIVE I'd get better millage with a 4.0. Don't get me wrong my 2.9 is has been a tough bastard and comes back for more but Id take a 4.0 any day. I have 2 friends with rangers, ones a 93 SC 4x4 4.0 auto with 31s, the other is 90 2.9 5 speed SC 4x4 with 28s and both have 3.73 gears. The 2.9 truck feels more peppy but they're equipped differently, one's an auto with 31s and the other is a manual with 28s.
4.0 FTW!

if you can do the electrical bullshit go for it.i could make my 91 sploder chirp third gear and my 91 2.9l would only chirp second gear.pretty much is the electrical and smog worth the big increase to you.there are superchargers and all kinds of stuff for 4.0l's also so you can approach v8 power levels.

Aftermarket is better ill admit for the 4.0L then the 2.9L. The 2.9L has just as much (if not more potenital) if the aftermarket woulda noticed it.

The 2.9L already makes more power per CI then a 351 lightning, or 302 HO motor, so by strict defintion its a high performance motor.

The 4.0L i drove was in a Ext cab 2wd with an auto, and the 2.9L has been in various ones, but i drove a 2.9L Regcab long bed 2wd, is what rusty is.

A supercab cant be 300lbs heavier then a Reg cab, so if the 4.0L is as torquey as everyone claims then 300lbs extra it still shoula run harder then the 2.9L, and i know that auto tranny didnt zap much.

Even the 2.9L Ext cab 4x4 with a 5sp i drove had more nuts to it then that 4.0L.

They both beat the pants off the 3.0, and the SOHC 4.0 is a decent motor, but the OHV 4.0 just isnt all that great.

later,
Dustin

rusty ol ranger said:

A supercab cant be 300lbs heavier then a Reg cab,

Click to expand...

Oh yes it can.
A 2nd generation ext cab 4.0L Automatic would easily weigh 300lb's more than a 1st generation reg cab.

My '92 4.0L 5 speed 4x4 Ranger with 3.55 gearing and 32" tires can still whip my stock '88 2.9L 4x4 5 speed with 3.45 gearing and stock sized tires quite easily.

Swap in the 4.0L. You won't regret it.

rusty ol ranger said:

No....not really.

Put some 4.10's behind that 2.9L....and you wont miss a 4.0L at all.

Some agree the 2.9L was very underrated from the factory.

later,
Dustin

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Dustin, Only one word comes to mind.... .

I already HAD 4.10's behind my 2.9.

I'm comparing apples to apples, a 2.9 with 4.10's Vs a 4.0
with 4.10's and I don't care what you do to a 2.9, my
freshly swapped 4.0 utterly stock '93 engine (except
for borla headers) will stomp your 2.9's dick into the dirt.

It isn't about a puny 1/4sec 0-60 it's about cutting the time by a third.
It's about going up hills with the 4.0 part throttle in fourth where
with the 2.9 you had to be SCREAMING @ WOT in third.

there simply is NO comparison

Now yes, I'm the one who first pointed out that the power/CID of the 2.9 is similar to the 351Lightning, but that is an impediment to improving the 2.9, the 4.0 has much more potential, because if a 4.0 was producing the same power relative to displacement as the 2.9 it would make 193hp

I think actually getting 200hp form a 4.0 is easier than getting more from a 2.9 would be...

The same old problem applies the higher the performance is stock the harder it is to improve upon it.

Now as for mileage, I'm close to being a champion at squeeking mileage froma 2.9, my best of 26.2 over a full tank of gas (all highway miles) is fantastic
However running at the same speed towing my 2000lb trailer and my 2.9's would drop to the High-12's or low-13's.
That being said the 4.0 while returning from Wyoming managed high-16's
and low-17's over a 1900miles distance and six tanks of gas.

Honestly I don't expect the peak mileage with the 4.0 to
be as good, but EPA estimates for the 4.0 in the early 90's
were 20-21 highway. I can live with that is it is about the same as my average mileage with the 2.9.

I simply haven't had the chance to drive the 4.0 with the truck
unloaded on the highway to find out how it'll do, but a "tight"
4.0 has gotta be better than an aging 2.9.


where the 2.9 was always straining the 4.0 just seems to loaf along and do things effortlessly.

I would not only put my 4.0 up against ANY 2.9 in a 4x4 supercab, but I'd be fairly confidant going up against
MOST 5.0 installs in a 4x4 supercab.

AD

The 302 is junk anyways. Its worthless in a truck. But still.....i gurantee it would be faster then a 4.0L, (Unless you have a worn out 302 and a fresh 4.0), and outpull it.

Ill get my 300 and whoop both of you (Pulling anyways).....and a 351 would eat us all alive.

Techinically its dumb to compare the 2.9L to the 4.0L, its like compareing a 4.3L to a 350....They were never made to compete against each other. The 2.9L competed with the 3.0, the 2.8L Chevy, etc, and it kicked both of there asses. The fact that the 2.9L can be compared in anyway to the 4.0 proves its a good engine.

My nephews 2.9L, (Port and polish, headers, 2.8 pistons, and some other goodies, incliding a cam) with 4.10 gears will walk a 4.0L Sohc with a stick shift.

A 2.9L is a hellacious running engine for what it is, The 2.9L is the best all around engine ever stuck in a ranger, it may not be as efficent as a 2.3L, and might not be quite as powerful as a 4.0L.....but its a good tradeoff. Alot better then the 3.nogo that replaced it.

Bottom line....its not worth the time and effort and BS you have to go through.

later,
Dustin

rusty ol ranger said:

its like compareing a 4.3L to a 350....

Click to expand...

Well some of us remember a 4.3L running with a 351W a couple of years back in a pulling contest.

Apples and Oranges.

ANY comparison of the different engines NOT involving a similar truck (Cab type, 2wd or 4x4, gearing) is worthless.

I've seen a non-turbo 2.3 that would walk 2.9's, but the 2.3 had 4.10's in a shortbed 2wd while the 2.9 was in a 4x4 supercab with 3.45's.

There was someone else locally that thought 4.0's were junk because he HAMMERED the one his brother had, problem is that a 2.9 with 4.10's shpould stomp all over a 4.0 with 3.08's....

Remember that it's more likely that a 4.0 truck has 3.27's or 3.55's than anything else and the difference in gears between 3.27's and 3.73's makes the difference between the engines a wash...

Objective fact, the 4.0 has far more "grunt" ANYWHERE in it's range than the 2.9 does and ALL the mods in the world will HURT the 2.9's bottom end grunt.
And frankly unless you are RACING (on a track) top end is less than useful.

Can you outrun me with your 2.8 pistoned highly modified 2.9? yeah, probably, but you are going to have to catch up to me first.

And remember that the 2.9 was only made from 1986 through 1992
while the 4.0 was made from 1990 through 2001 and MANY TIMES
more 4.0's were made, and the 2.9's out there are only getting older
The very youngest are already 16 years old!

AD



AllanD

the only thing i diden't like about the 4.0l in my 91 sploder was it would start to misfire if you ran through water too much and splashed it around the engine compartment.i've been up to the bottom of the headlights in my 2.9l truck and it diden't cut out with a relocated air intake.(but if my truck stopped while up to the lights i'de probably be shit out of luck).i know it could just be that particular truck but anyone else have their 4.0l start sputtering after a few mud runs?