Head Porting for Fuel Milage

[Tom68]

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.

You do realise those two objectives on a petrol engine are in conflict, look at how LS engines have been specced over the last 20 years, they don't have good low speed torque considering their capacity, they do get good fuel economy, when you need power you rev them and ignore the fuel consumption.

[PackardV8]

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. 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.

Not a fan of the 2.8 or 2.9 versions. They all have cracked cylinder heads. In my experience, a 4.0 will run faster, last longer and get almost the same fuel economy.

[frnkeore]

The 2.8, Cologne (Germany) engine, has no similarities to the 4.0, which is a up grade of Fords first American "Metric" engine, the 3.8.

[BCjohnny]

IIRC ......

The 3.8 was a 90* V6, with the common SBF bellhousing pattern, built in Canada ..... 'Essex V6' (not to be confused with the English 2.5/3.0 'Essex V6')

The 4.0 was a 60* V6 based on the smaller 2.0-2.9l, built in Germany ..... 'Cologne V6'

I think the 4.0 has bellhousing pattern differences to the smaller 'Colognes', so you might want to check if going this route

If so I'd pick up a cheap 2.9 and rebuild that, it's a better design (no adjacent exhaust valves, so doesn't crack so easily) and the 2.8 manifold will fit with mods

[PackardV8]

The 2.8, Cologne (Germany) engine, has no similarities to the 4.0, which is a up grade of Fords first American "Metric" engine, the 3.8.

If we stay here long enough, we'll all be wrong about something; this is yours.

The Cologne V6 has evolved through engine displacements of 1.8, 2.0, 2.3, 2.4, 2.6, 2.8, 2.9, and 4.0 litres.

[BLSTIC]

Are there longer reach spark plugs available? That will get you some efficiency and detonation resistance because of reduced burn time. If possible get ones that are factory side-gapped (the two or three ground electrode items can be) as they have shorter ground straps and less shrouding. Piston and valve to plug clearance may or may not be thing, you should check.

You should investigate textured inlet ports to help keep fuel in suspension.

A good set of headers will help. Three cylinder headers are easier to make 'right' than cross-plane V8 headers and with the likely short cam timing you'll have it will mainly come down to port-manifold transition, long radius bends, merge collectors, and using a probably very small pipe compared to what you'll usually see on here. As in, if you're making less than 300hp 1.5" off the head is likely too big, and if you're at 200hp it's *definitely* too big. I have no idea what size the exhaust ports are but you do not want to be making them bigger for the sake of flow bench numbers just to shrink them down after the header flange to get decent scavenging.

Run a good breather/catch can system. Oil in the intake long term clogs things up and short term costs octane (which puts limits on ignition timing and costs torque and efficiency)

Beyond that you're stuck with an engine that has too much against it in terms of combustion chamber and port design, and on top of that staying with a carb and non programmable ignition are further limits. You could change to a carb that has better atomisation properties (or modify your own).

[mag2555]

Getting the chambers and valves heat barrier coated can produce the same result as raising the compression by 1/2 a point, but without increasing the chances of ping or knock.

[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.

You do realise those two objectives on a petrol engine are in conflict, look at how LS engines have been specced over the last 20 years, they don't have good low speed torque considering their capacity, they do get good fuel economy, when you need power you rev them and ignore the fuel consumption.

No, I did not realize the objectives are in conflict. Explain more please.

[BobbyB]

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. 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.

Not a fan of the 2.8 or 2.9 versions. They all have cracked cylinder heads. In my experience, a 4.0 will run faster, last longer and get almost the same fuel economy.

Bought truck new in 1983. Rebuilt engine at about 180,000 miles. No cracks. Rebuilt again at about 360,000 miles. No cracks. Heads now have over 550,000 miles on them…. Might be cracked.

Picked up 2 “ rebuildable cores” to hopefully get 1 engine built. Tearing the first one down now and hope to remove heads today.

[travis]

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.

You do realise those two objectives on a petrol engine are in conflict, look at how LS engines have been specced over the last 20 years, they don't have good low speed torque considering their capacity, they do get good fuel economy, when you need power you rev them and ignore the fuel consumption.

That is not an apples to apples comparison though. EFI and computer controlled ignition timing vs carb and vacuum advance distributor...they use 2 different approaches to achieve fuel economy.
There is no denying that trucks made in the last 20 some odd years get good fuel economy (I'm talking the typical 5.3 GM or Coyote 5.0), but the lack of low end torque in a truck application drives me nuts. Modern 6-8-10 speed transmissions have certainly helped here though.

I haven't touched a 2.8 Ford in probably 30 years, but I certainly remember going through piles of junkyard engines trying to find crack free heads.

I will say that as long as there are no other major restrictions, I have yet to see anything that hasn't responded positively to a bit of bowl porting and casting clean up.

[Walter R. Malik]

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.

If it uses a carburetor or throttle body injection there should be no sharp corners within and very smooth transitions keeping the fuel in suspension.

[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. 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.

Not a fan of the 2.8 or 2.9 versions. They all have cracked cylinder heads. In my experience, a 4.0 will run faster, last longer and get almost the same fuel economy.

They were before my time, so I don't know what they look like. A lot of gone by the way side engines like that. Which is probably a good thing.

[Tom68]

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.

You do realise those two objectives on a petrol engine are in conflict, look at how LS engines have been specced over the last 20 years, they don't have good low speed torque considering their capacity, they do get good fuel economy, when you need power you rev them and ignore the fuel consumption.

No, I did not realize the objectives are in conflict. Explain more please.

If you have high torque at cruise RPM you'll be running at high vacuum, good for fuel atomisation, bad for economy.

You can get the fuel atomisation with manifold heat and sharp edges on the valves and seats and your peak torque needs to be above your cruise rpm so there is less pumping loss.

[PackardV8]

You do realise those two objectives on a petrol engine are in conflict, look at how LS engines have been specced over the last 20 years, they don't have good low speed torque considering their capacity, they do get good fuel economy, when you need power you rev them and ignore the fuel consumption.

No, I did not realize the objectives are in conflict. Explain more please.

If you have high torque at cruise RPM you'll be running at high vacuum, good for fuel atomisation, bad for economy.

You can get the fuel atomisation with manifold heat and sharp edges on the valves and seats and your peak torque needs to be above your cruise rpm so there is less pumping loss.

Same but different, for forty years, when gas was cheaper, the SBC with carb and distributor, was of necessity geared to turn RPM. When emissions requirements forced the adoption of EFI, computers and overdrive automatics, for the first time, the SBC could be tuned for WOT hard pulls at 1500 - 1800. From this came main bearing failures, never-before-seen on SBCs.

[Tom68]

No, I did not realize the objectives are in conflict. Explain more please.

If you have high torque at cruise RPM you'll be running at high vacuum, good for fuel atomisation, bad for economy.

You can get the fuel atomisation with manifold heat and sharp edges on the valves and seats and your peak torque needs to be above your cruise rpm so there is less pumping loss.

If you do build a low rpm high torque engine, EGR could be used to reduce pumping losses.