Which is a better motor from Ford, the 4.0 they put in the Explorer or the pushrod 4.2 that's in the f-150? If I understand correctly, Ford has been using the 4.0 in the explorer since before 1997 - I wonder why they made a new pushrod v6 for trucks that make the same HP as the 4.0 sohc explorers do?? Wouldn't it have made better sense (cost-wise) for Ford to just build more 4.0's rather than taking the risk of introducing a new engine?

Stephen

 

The 4.0L I believe was redesigned in 200 from ohv to sohc. The power increase was very signifigant like 38 more hp not sure about torque. The 4.2L is a ohv (pushrod) which is a pretty decent engine. The 4.2L was released when 4.0L ohv was at a mediocere 170hp. Currently it would make sense for Ford to put the 4.0L Sohc instead of 4.2L because more efficent gas milege. The one loss would be about 14lbs feet of torque but the 4.0L makes up 5 more hp. Very good question interesting to see answers

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2001 F-150 5.4L trition,
Regular cab with 8' bed
XLT with Black Clearcoat
4x4 3.55 limited slip
factory cab steps
class III tow package
Factory ordered: 12/5
recieved: 2/22

Current Mods: Ford Plastic bedliner, Bug Deflector II

 

You must also remember that the 4.2 and 3.8 are very closely related so that saved Ford a ton of R&D money. The 4.0 is a good motor but with all the V6 mustang guys developing tons of new things for the 3.8 it can only benifit us guys with the 4.2. And as for as gas mileage i get 15 or 16 mpg not too bad for a full size truck, if people are worried about gas mileage buy a 4 cylinder Ranger.Just my opinion i do like my 4.2 it has been a great motor so far!

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98STX
4.2 V6 5 SPD 3.55 Gears
Black Clearcoat
AVS Bugflector II
AVS Window Visors
Pendaliner Bedliner
Pioneer 12 disk changer w/wireless remote
PERFORMANCE MODS
Superchip
Gibson Side Swept Catback
K&N Filter
FUTURE MODS
FIPK(AirForce One,Airaid)
Ignition Upgrade(MSD,Jacobs)
Pulleys??

 

I don't think that there is any one right answer to your question . . .the 4.0 is redesigned and is great for the ranger and explorer . . .because those vehicles aren't as heavy and aren't as likely to pull/haul heavy loads . . .the 4.0 has great numbers for HP and torque but they are both VERY high in the rpm band . . .probably inappropriate for an F150 that is heavier and may have a payload to haul . . .put the 4.0 in F150 and i believe that you'd have people screaming "where is the power? i have to wind the crap out of this thing to get any power!" the 4.2 is older tech but more appropriate to the F150 . . .so, they are both good engines and both installed where their HP and torque characteristics work best . . .

 

You also have to look at the horsepower and torque curves....I would venture to say that the 4.2 has more power in a flatter curve.

 

From what I hear from magazines the 4.0L sohc redesign is a great engine. I don't believe it will break down like stated. However Car and Driver recommends getting the 4.6L v8 as a option in the explorer. They said you will be much more happier with power and gas mileage difference is very few mpgs.

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2001 F-150 5.4L trition,
Regular cab with 8' bed
XLT with Black Clearcoat
4x4 3.55 limited slip
factory cab steps
class III tow package
Factory ordered: 12/5
recieved: 2/22

Current Mods: Ford Plastic bedliner, Bug Deflector II

 

A couple of reasons come to mind when comparing these two engines:

1. Reliability. I have heard from many techs that the 4.0L SOHC engine is a maintnance nightmare. They almost constantly have them in for repairs. Granted, they have been a very popular engine of late, but, they say the the numbers are disproportionate. The 4.2L OHV in the F-150 is a very reliable engine, second only to the 4.6L 2v Truck engine. Aside from the recall for the water pump, everything else has been performing very well.

2) Power delivery: The speculation about the torque curves is right on. If you look at www.blueovalnews.com and peruse their engine section, you can get a listing of the 1999 Ford Truck engines for the ranger up to the V-10. The 4.0 SOHC is rated for almost exactly the same numbers as the 4.2, however, the RPM for peak torque is higher, as well as the RPM for peak Horsepower. For a truck, especially a mid-sized one like the 150, you want the power low in the torque curve. Granted, for the kinds of things that we do on this board, a high reving 4.0 would seem like fun, and, there are about as many parts available for it as there are for the 4.2. Since it spins faster, it gains more from a FIPK and exhaust mods (higher reving = more air flow) the 12 cubic inch difference in their size notwithstanding.

3) application suitability: As I understand it, Ford would need a bell-housing adapter for the 4.0 to put it on the trucks, adding cost and weight to the setup. The 4.2 fits the trasnmissions in use because it was made for them. The 4.0 has a different bolt pattern.

4) Economy: The 4.0 is a marginally better engine from a fuel economy standpoint, however, if you take upkeep into consideration, it doesn't stand up as well. The Overhead cams use timing belts that will require maintnance sooner than a timing chain on the 4.2. The cost of upkeep plays into the overall economy costs. Also, the MPG difference is not as much as people think. To get the power out of the 4.0 that we get out of the 4.2, it needs to spin faster. Consequently, it needs to burn PROPORTIONATELY more fuel to get there, making the final tally almost even.

In other words, a 4.0 in an F-150 would weigh just as much, maybe get .2 to .5 better MPG, and break down more often. It would be more expensive to keep up and be of no real advantage.

Now, A DOHC 4.0L that was more reliable than the current 4.0 would be nice. The low RPMs could be set up to lean more heavily on torque and efficiency and the high rpms could be set to lean heavily into the HP range. That would give a nicer torque curve, and a nice top end for the fun we like to have.

 

what either of these engines would benefit from greatly is variable cam timing. our car has variable cam timing giving it great low end torque and then adjusting to give it great top end horsepower . . . this technological feature benefits smaller displacement engines greatly . . .another benefit is improved economy . . .