I've been thinking again (scary, aint it?) It seems to me that most manufacturers are concerned about HP on their new engines, to sell vehicles. Accordingly, mileage has suffered. It's still ok, but come on, my 390 equipped '70 F100 can regularly get 15mpg.

So the idea came to me: Why doesn't Ford offer an optional engine for their trucks, with a milder cam, and slightly smaller ports and valves? Something that would get 25mpg regularly, and have loads of low end torque. Something that would run out of wind at, say, 3500rpm, and have the torque peak at 1500rpm. Built this way, it'd have to last forever, never being spun up very fast. I know it would be kind of a slug and wouldn't have a whole lot of horsepower, but some people just dont care if a truck goes fast. They want torque, mileage and durability. They dont give a rats other end about horsepower. Put an extra low stall torque converter behind it, and you'd have a nice truck IMO. I'd buy one.

Like I said, keep the engine line-up the way it is, but add this as an option. I'd probably be more inclined to buy a new truck if it has something like this.

A different cam profile and some different heads shouldn't be too hard to do.

What do ya think?

 

I think's it a great idea. After all look what the 302 did for truck sales. They at one time put the 2.9, and the 3.8 in the full size trucks. These were attempts at a fuel efficient truck, but failed pretty miserably. The other problem is that if you had an engine with a redline of 3500, and a torque peak of 1500 (a small diesel would be great) the customer base wouldn't be there. Most people are used to 4 cyl cars and seeing the tach race up to 4k before shifts, and cruising at 2500 or so... The other drawback is longevity. That engine would more than likely go well over 200k miles, and would not warrant many return customers. Sure it's tough as nails, but people also want SOME performance.. I'd buy one because I like the idea. I don't need to win any races, and fuel economy is most important right now.

 

Well maybe not redline at 3500rpm, maybe more like 4000rpm, but you get the idea. It would still have some power. The numbers I'm thinking would be around 440ft-lbs @ 1500rpm, and 250hp @ 3500rpm or so, peak. This out of a 5.4L V8. It'd still move the truck plenty well.

I agree that most people are used to having to rev up the engine to get power. That's why I said make it an option. This option isn't for them. This is for the guy who doesn't care about winning a race and just wants to get there without burning a lot of gas; for the contractor that pulls a trailer and doesn't want to spend the extra money on a diesel.

Probably help Ford's CAFE numbers, too.

 

25 MPG out of a 5.4L V8 with 250HP and 440 ft-lbs of torque?

Ford has some pretty good engineers, but they're not magicians.

 

It's all in the cam profile. Make it a short duration, low lift cam and it will sip fuel.. It won't be quick, but it will sip fuel. And if it's tuned right there is no reason why it can't get at least 20 mpg.

 

up your redline to 4500-5000 and Ford made that engine for decades.
One of the reasons they killed it, was because it was too tall for the 97 body style. 25mpg is pushing it, but 80-81 4x4 f150s pulled 18 mpg.

 

Just look at the old straight six. Gobs of low end torque but no horsepower. It wouldn't accelerate very well. Normal people don't know the difference and just think the engine is slow. Ford shifted along with customer demand of a truck that is more like a car. So now they build trucks that arn't like the straight six of the past. Plus, that straight six doesn't fit in the new body style, but the windsor V-8s were more like the straight six than the new mod motors.

 

I think a lot of the problem with economy now is that the "big" v8 is less than half a litre more than their old small v8. The engine is just being overworked. A larger engine would get better mileage because it would have more reserve power available. If you were to add, say, a litre to the engine, make it a 6.4, then you would see some improvement in mileage and power. Plus, they could pull from the company's history and make a "GT390" package. With today's technology and Ford's current OHC design, there is no reason why that engine in normal trim can't make 410hp, 425lbs/tq, and get 23-24mpg. Dual overhead cams with variable timing on both (they already have that on Jaguars), maybe direct injection, and possibly a displacement on demand system. This engine would do everything you wanted it to.

 

My father told me his '77 F150 with a 302/3 speed auto got 22 to 24mpg... All the time..

 

Then his speedo's off lol....

 

They already have it, its called a diesel.

 

No justin, that was what he got when he moved to florida.

 

The old 400 was a low RPM torque motor as designed but EPA regulations killed it. It was like the old 300-6 but with more torque and power. Built and geared right it can get great mileage.

 

Eric, wasn't it a square motor?? I mean the bore and stroke were both the same? The 400 was a good motor, we had one in a '79 F250.. After replacing the heads it was good running truck.

 

The 400 is a square motor 4" stroke and 4" bore with long 6.58" rods.