4.0 SOHC vs 3.0

[cbxer55]

When I moved from CA to Oklahoma in 02, I towed a heavy ass trailer behind my 3.0. Through the mountains of Flagstaff, New Mejico. No problemo. Only thing I did was keep the OD off when on uphills. Other than that, let it go into OD on the flats and downhills. Never noticed any lack of power. I thought it did quite well for what it is.

 

[8thTon]

But you are still working the engine at a 20% higher rpm range... the gear ratio has nothing to do with where your engine makes power.

Who cares where the engine makes power? Power matters at the wheel rpm, which is what the gears are for. Gears will translate the entire shape of the power curve to whatever rpm is needed at the wheel. Within reason 20% more rpm will not bother any modern engine, and if it's designed for that the accessories will be geared down appropriately.

In fact both these engines have a 5200rpm hp peak (at least my 2004 3.0 does). It's hard to tell how flat the power curve is without a plot, but the 3.0 is not a peaky engine. The 4.0 is making 136hp at its torque peak of 3000rpm. The 3.0 is making 134hp at its torque peak of 3900rpm. The only plot I found was for a 2005 Taurus 3.0 which had a very flat torque curve between 3000-4000rpm, but that's a different cam and manifolds.

Anyway, of course the 4.0 makes more power, it's a 30% bigger engine - and in fact it makes 30% more power. My point was that Ford derived not one benefit from the entire SOHC design on the engine. They could have staggered the valves out of line like a Lima 4cyl, or they could have used 3 or 4 valves per cylinder. If they got port shapes that flowed better that would help power at rpm, not so much the low rpm torque peak, but they only did as well as the pushrod 3.0. It's still a 2 valve engine with all the valves parallel and lined up, running at 6000rpm and below where pushrods would work the same.

 

[Uncle Gump]

Actually... I care where my engine makes power.

 

[Uncle Gump]

I'm not gonna go research this... But I think I remember the SOHC having a much flatter curve then the OHV... and better peak numbers... so I don't think it's a total loss of engineering dollars Could they have done more with it during development... Probably.

 

[cbxer55]

Well, my 3.0 has the 3.73 gears. And it works fine for me. As I said, I get to drive 4.0 Rangers at work. And I have no desire to go out and buy one, I'll keep my 3.0 thank you very much.

Someone on the first page said "don't drive it like you stole it." I beat my 3.0 like a red-headed step child, whip it like a rented mule. It takes it all and comes back for more.

 

[85_Ranger4x4]

Mom babied her ‘02 Explorer... sound like it had a bunch of marbles in the engine when she dumped it at 160k. The ‘94 before that was traded at 180k and was still seen running around town years after the ‘02 was traded in.

I think they put too many bandaids on it IMO.

The 3.0 is a very tough and durable engine, I would rather have that than a time bomb disguised as 18 miles of timing chains on both the front and the back of an engine. I would rather have just about any other RBV engine except maybe the 2.9... I would call that about a tie for time bombness.

 

[Uncle Gump]

cbxer... I'm not trying to change your mind on anything. Rock On with your 3.0L

 

[cbxer55]

cbxer... I'm not trying to change your mind on anything. Rock On with your 3.0L

You couldn't anyway, I've had it for 19 years now. Every once in a while, I think about getting rid of it. But likely couldn't sell it for $1000. So why bother? I'll just keep using it as my daily driver til it decides not to run anymore. LOL!!

 

[19Walt93]

I bought 2 new Rangers with 4.0 SOHC engines even though I don't like them, they're typical over engineered, over complicated, German engines. I would have much preferred a late 4.0 OHV if it had been available. Four timing chains with 1 from the back of the balance shaft to drive the right cam from the rear, all so they didn't have to make a mirror image head casting for the right side. Before ordering my 04 Ranger I test drove a regular cab short bed 4x4 with a 3.0(nice car engine), 5 speed and 4.10 gears. I accelerated up a steep ramp onto the highway, crested the hill at about 60 and shifted to 5th gear and immediately shifted back to 4th because I couldn't maintain 60 on a slight ( for NH) upgrade. Maybe an automatic would have done better but I didn't want one. The 2.9's had their share of oil leaks but they felt like they had a lot more low end torque than the 3.0.

 

[8thTon]

I bought 2 new Rangers with 4.0 SOHC engines even though I don't like them, they're typical over engineered, over complicated, German engines. I would have much preferred a late 4.0 OHV if it had been available. Four timing chains with 1 from the back of the balance shaft to drive the right cam from the rear, all so they didn't have to make a mirror image head casting for the right side. Before ordering my 04 Ranger I test drove a regular cab short bed 4x4 with a 3.0(nice car engine), 5 speed and 4.10 gears. I accelerated up a steep ramp onto the highway, crested the hill at about 60 and shifted to 5th gear and immediately shifted back to 4th because I couldn't maintain 60 on a slight ( for NH) upgrade. Maybe an automatic would have done better but I didn't want one. The 2.9's had their share of oil leaks but they felt like they had a lot more low end torque than the 3.0.

I agree on the German engineering - why use 1 part when 5 will do? And how much money did they spend to avoid a mirror image casting?

On that 2004 3.0 you tested, assuming it had 235/75-15's you would have been turning 2260 engine rpm in 5th (0.79 overdrive) at 60mph. Not gonna be too lively there, but then again it has other gears. Obviously a larger engine will be making more power.

My 2004 Edge with 4.10:1 gears and an auto (0.75 overdrive) is turning even slower at 60mph, but it can shift at will, and can unlock the torque converter too. It rarely feels poky.

 

[cbxer55]

I keep the OD turned off on both my Ranger and my Lightning, for in town use. I only turn it on when I hit the highway or speeds over 55 to 60 mph. Makes driving the 3.0 more enjoyable, since it's not constantly hunting around for the appropriate gear. The Lightning is the same, around town, it hunts between 3rd and OD all the time. Irritating. On both trucks, it doesn't affect mileage even one mpg. My 3.0 gets 18 around town, and 20 or better highway. My Lightning, don't ask!!

As soon as the truck is running, I pop the OD off. And leave it there.

 

[Uncle Gump]

Not that I want to keep this debate going... but that is exactly why I like the low end torque of my SOHC. I find it enjoyable to drive regardless of the position of the O/D cancel switch. If it wants the next gear... it just takes it and pulls it.

 

[8thTon]

I never turn off the OD on my 3.0, if that seems necessary and it’s hunting for gears then try cleaning the MAFS. Mine does not hunt aound for the right gear at any speeds.

 

[cbxer55]

I just like, in both my Lightning and Ranger, when driving around town with the OD off, when you put your foot in it, you don't have to wait for that delay before the trans shifts out of OD. It's already out of OD, and wham you're gone. Plus, my intake probably exacerbates the already rev happy motor. The crimped down stock tube helps keep intake velocity high during slow movement. When you put a full three inch tube on there, it slows the airflow down. Keeping it out of OD helps keep the intake flow high. But, when the rpm's are up, it sure sings a nice tune. Even without a muffler, the intake noise is louder when the petal is down.

I tried putting the stock intake tube on with the cone filter. Don't like it at all. Totally kills the power it makes with that big tube. It's an old MAC intake. Can't get them any more.

I'll have to take another picture, it's not the same exactly. Different sleeves, different filter. Spectre stainless steel mesh filter. Way less restriction than any other filter out there. Way louder as well.

 

[19Walt93]

I don't consider the 4.0 SOHC to have any low end torque, the 89 F150 that I replaced with my 04 Ranger had a 300 with a T18 transmission and 3.08 gears. I could drive 25-30 mph in 4th gear at 800 rpm, step on the gas and it would gain speed without complaining, or stick it in creeper gear and pull stumps. It also got about the same gas mileage as the 4.0, 5 speed, 4x4 supercab. The Ranger was way better at highway cruising, the 300 was happiest at about 62 mph.