Head Porting for Fuel Milage

[BobbyB]

Currently rebuilding a 2.8 ford V6 for an 83 ranger 4x4 truck with 4 speed manual transmission.

What modifications to the heads will help with fuel milage and low speed torque? I am not concerned with peak horsepower.

I expect to have Mike regrind a cam. I have access to a flowbench.

[PackardV8]

Carb or EFI? It makes a difference.

[mt-engines]

Its a gas engine. Don't expect it to drive like a turbo diesel.

Just some bowl work is more than enough since you aren't trying to move peak torque up.

I would say have Mike grind you a cam and find someone with a load cell and wideband.

Then go after tires and aero. Look at some new gmc and Ford trucks carefully, you will notice immediately.

[Wetflow]

Would a 5 angle valve job on the intake and radius on the exhaust also help with this?

[BobbyB]

Carb or EFI? It makes a difference.

2 barrel carb

[mag2555]

The bottom line in terms of what your talking about here is efficiency.

Improvements in assisting the motor to not have to work at pumping out the Exh gasses that it does produce is where I would start with.

[David Redszus]

Raise the compression ratio. That will improve efficiency across the entire rpm range.

Put it on a dyno and plot the BSFC curves.

Drive the vehicle in the rpm sweet spot. (see typical BSFC curves)

[BOOT]

As others said efficiency, just cleaning up n blending bad edges/alignments, Intake manifold & exhaust as well.

[PackardV8]

Currently rebuilding a 2.8 ford V6 for an 83 ranger 4x4 truck with 4 speed manual transmission. . . . 2 barrel carb

There are some 2-bbls of that vintage like half a QuadraJet; small primary, large vacuum secondary. Which carb will you be using?

[BobbyB]

Raise the compression ratio. That will improve efficiency across the entire rpm range.

Put it on a dyno and plot the BSFC curves.

Drive the vehicle in the rpm sweet spot. (see typical BSFC curves)

Where do I find typical BSFC curves?

[BobbyB]

Currently rebuilding a 2.8 ford V6 for an 83 ranger 4x4 truck with 4 speed manual transmission. . . . 2 barrel carb

There are some 2-bbls of that vintage like half a QuadraJet; small primary, large vacuum secondary. Which carb will you be using?

Either a motorcraft 2150 or Holley 350. Might try annular boosters in the Holley.

[BobbyB]

Raise the compression ratio. That will improve efficiency across the entire rpm range.

Put it on a dyno and plot the BSFC curves.

Drive the vehicle in the rpm sweet spot. (see typical BSFC curves)

How high do you think I can safely go with iron heads and 87 octane fuel? I do not plant to use a computer controlled ignition or knock sensor.

[Bigchief632]

If the 2.8 is like the 4.0 they used a bazillion of in the Rangers in later years, there's BIG gains available. I used to do a fair number of those heads for repair shops back in the day. Early 2000 era. I remember one in particular, this truck was the guys baby. Had it since new. It was immaculate. Had 130k. Started using antifreeze, my friend's repair shop determined it was a head gasket going away. Guy said fix it, do whatever it takes, it's my baby and I want it perfect.

I did a lot of heads for them and was told, price is no object, replace or do whatever they need. Ok. Guides were smoked, exhaust seats were pounded (induction hardened), assuming the 2.8 seats are also? And the exhaust valves were junk. I ordered new SBI replacement exhaust valves, and the seats they listed for that engine. When I installed the seats, the was a giant ridge left under the valve in the throat, the as cast throat size was ridiculously undersized for the valve diameter, maybe on purpose? But probably not. So I set up a throat cutter, removed the ridge, did a nice radius performance type exhaust seat, did a more performance oriented intake seat, still with basically "stock" angles, just put the seat closer to the outer edge, still used a 30 degree top cut, it was stock after all, and it allowed me to add a 4th angle and use a throat cut to open the intake bowl up some. Then I hand blended the bowls, without getting carried away, but it was a VERY dramatic difference. I also back cut the intake valves, and surfaced the heads .015, to give it a little bump in compression without going to far and causing issues with geometry or intake fitment.

It woke the thing up so much, the mechanic called me to ask WTF did I do to those heads? He said he had worked on the truck for 100,000 miles and drove it many times. He said it will light the tire up from a roll, it's literally fast, and it made him giggle, he could not believe how much that made a difference. Guy picks truck up, comes back after 5 minutes, and asked them the same question. WTF did you guys do to my truck? After a week, he reported that he gained 5+mpg. So, if your 2.8 is anything like the 4.0 litres, which I'd imagine it is, there's a fair gain to be had.

[1980RS]

Best things for fuel mileage are a super good valve job and compression and drive with a light foot.

[Tom68]

Raise the compression ratio. That will improve efficiency across the entire rpm range.

Put it on a dyno and plot the BSFC curves.

Drive the vehicle in the rpm sweet spot. (see typical BSFC curves)

Where do I find typical BSFC curves?

You're making it by head work and cam selection.