Good F350 fuel economy?

[TheGrimMechanic]

Originally Posted by RustyLugNut

Emissions aside, what you are doing with your truck to reach your goal of 24 mpg is laudable and important as pickups make up a large percentage of some communities. Once you have exhausted the easy engine modifications, you can peruse the aerodynamic possibilities. That opens up a world of gains as our trucks come factory equipped with horrid coefficients of drag.

Aerodynamic mods are pretty much out of the question since the vehicle has the frontal profile of a barn door to begin with and it frequently gets used off-road.

The next step will to replace the stock ECM with an ECM from a 1996 Bronco or F150 that has the same drivetrain package and California emissions equipment. Two reasons for this; Even though my F350 is a 1997 model, it isn't OBDII. OBDII didn't apply to vehicles over 7,000GVW until 1998. Switching the ECU to an OBDII compliant one will allow me to view live data. The California specific ECU is also a mass-air unit and will allow me to convert from the stock speed-density fuel injection strategy to mass-air. There are kits available with the associated piggyback wiring, ECU, MAF meter, etc. Kit cost is about $600. This change alone should net around 1-2 mpg improvements because of the improved accuracy in fuel metering.

After this, the changes will revolve around building a new engine. The stock 351w powerplant is pretty reliable and there is a HUGE aftermarket for parts. Of course, many of the parts are for improved performance/horsepower but a lot of the same mods that increase specific output can improve efficiency/FE at the same time. Here's a list of what will be changed in the rebuilt engine:

1. Swap the heads for a set of TFS Twisted Wedge heads with 190cc intake runners and 62cc combustion chambers. These are arguably the best head for the 351w from a performance standpoint but they also have a very efficient 'fast burn' combustion chamber design. They also have reduced combustion chamber volume from the stock head and will allow for a 10.5:1 compression ratio with flat-top pistons. Obviously, the impact on fuel economy will be from the ability to tune for lean-burn operation and increase efficiency from the raised compression. This head-piston combination should run just fine on 87 octane fuel and possibly be ok with 85 octane at the 4,700 ft elevation I live at. Heads will also get a set of full roller rocker arms (reduce frictional losses in the valvetrain). The heads alone will not get me to where I want without some careful prep work to the bock. The block/head combination will need to be set up with a quench clearance (sometimes called 'squish') between .040" and .060". The quench area is the space between the flat part of the cylinder head (deck) and the top of the piston when it's at TDC. The .040-.060 clearance is important to promote turbulence in the combustion chamber and to increase the engines resistance to detonation. Most stock engines have a quench clearance from .080 to .100+. Quench clearance this large has the opposite effect by making detonation more likely and allowing a portion of the flame front to be extinguished while leaving some unburned fuel in the large quench area.

2. Regrind the crank to use 351c main bearings instead of the stock 351w bearings. The 351w main bearings are 3.000 inches in diameter. 351c mains are 2.750. Clevite makes swap bearings for this change. This is an old trick used by engine builders to pick up some free power and also has the benefit of reducing the oil flow necessary to lube the bottom end. Several benefits here: Reduced frictional loss, lower burden on the oil pump allowing the use of very light weigh lubricating oil, and less windage loss inside the crankcase because of the reduced oil flow. A windage tray will also be used to further reduce windage loss.

3. Use gapless compression rings, low tension oil rings, and flat-top hypereutectic pistons. The gapless compression rings can add from 1-3% in efficiency alone. The low tension oil rings can reduce rotational torque by 40%. The hypereutectic pistons have a lower coefficient of expansion than forged pistons and are stronger that stock cast pistons.

Still doing a lot of research on cam profiles and I haven't made a decision if I'm going to use something 'off the shelf' or go with a custom grind.

The transmission is still up in the air too. I'm not too fond of the ZF 5-speed manual tranny that Ford used and there are some expensive swap issues if I want to go to a NVG 4500 (5-speed) or NVG 5600 (6-speed). I may stick with the E4OD 4-speed automatic that's in it and use an improved torque converter. There is also the possibility that I can figure out if I can build the E4OD to use the newest specification Mercon LV transmission fluid. Mercon LV spec tranny fluid is very light viscosity fluid and should be good for some significant improvements in the efficiency of the transmission.

Once the engine/transmission assembly is ready to swap, I can begin the process of refining the ECU programming for the new combination. That will be the biggest mental challenge and also the most fun part of this project!

[TheGrimMechanic]

Originally Posted by RustyLugNut

Here is a link to the EPA that sketches out the importance of NOx reduction as the interaction of VOCs, NOx and sunlight result in large levels of ground level ozone.

Frequent Questions | Ground-level Ozone Standards Designations | US EPA

The information the EPA has here seems somewhat misleading. From what I remember about my chemistry, N20 (nitrous oxide) is a powerful reducer of ozone and is considered an 'ozone depleting chemical' similar to R-12. Of course we have to make the distinction about 'good ozone' and 'bad ozone' here. 'Good ozone' being the ozone found high up in the atmosphere that blocks UVB, and 'bad ozone' found at ground level (and is considered a pollutant). One could argue that the presence of N2O at ground level has a beneficial effect with its respect towards its interaction with ozone at ground level. NO (nitric oxide) is a free radical and has a very short half life most likely ending up as NO2 (the red gas, nitrogen dioxide). And NO2 reacts with water in the atmosphere to make nitric acid (HNO3). Which most likely ends up in the soil (from rain), and again could arguably be considered a benefit to plant life by fixing nitrogen to the soil.

Not that I'm arguing for [I]increased[I] emissions of NOX. I grew up in Southern California in the 1960's and '70's and remember the brown cloud and the sore throats and tight chests from it. It's no fun using your lungs as a nitric acid factory. Just bringing up the point that there are always two sides to every argument but logic doesn't always dictate the winner.

The driving public and consumer are just low lying fruit with respect to how the EPA imposes its rules and regulations. If you look at the big picture, ocean shipping probably contributes more to global air pollution in one day than all automobiles driven in the United States in an entire year. Typical ocean transports are virtually unregulated with respect towards exhaust emissions and they use the worst fuel imaginable for propelling their loads of freight from mainland china to your local Wal Mart. Most of the ships fire their boilers with 'bunker oil'. The bottom of the refining tree residue that unusable for anything else because of sulphur content, mercury, etc. Burning tires probably pollutes less than burning 'bunker oil'.

[chillsworld]

Wow, I've never seen someone break down the 351 like you just did. It sounds like you would be very close to the 24mpg goal you have set for yourself... Assuming you can keep your right foot out of it

I wish I was 1/2 as knowledgeable about my 5.0 as you are with your 351

~C

[TheGrimMechanic]

Originally Posted by chillsworld

Wow, I've never seen someone break down the 351 like you just did. It sounds like you would be very close to the 24mpg goal you have set for yourself... Assuming you can keep your right foot out of it

I wish I was 1/2 as knowledgeable about my 5.0 as you are with your 351

~C

If I get the tuning right (a lot of trial and error I'm sure), I should still be able to manage 15+mpg while hauling my little camp trailer and a couple of motorcycles in the back.

I had a 1981 VW Rabbit pickup about 15 years ago. Put a turbodiesel engine out of a Jetta in it. I loved that truck. It got 45mpg and it had enough power to stay above 50mph over the top of Vail Pass (10,300 ft. elevation) with a passenger and two motorcycles in the back. Traded it for another motorcycle. Should have kept the truck.

[RustyLugNut]

Originally Posted by TheGrimMechanic

The information the EPA has here seems somewhat misleading. From what I remember about my chemistry, N20 (nitrous oxide) is a powerful reducer of ozone and is considered an 'ozone depleting chemical' similar to R-12. Of course we have to make the distinction about 'good ozone' and 'bad ozone' here. 'Good ozone' being the ozone found high up in the atmosphere that blocks UVB, and 'bad ozone' found at ground level (and is considered a pollutant). One could argue that the presence of N2O at ground level has a beneficial effect with its respect towards its interaction with ozone at ground level. NO (nitric oxide) is a free radical and has a very short half life most likely ending up as NO2 (the red gas, nitrogen dioxide). And NO2 reacts with water in the atmosphere to make nitric acid (HNO3). Which most likely ends up in the soil (from rain), and again could arguably be considered a benefit to plant life by fixing nitrogen to the soil.

Not that I'm arguing for [I]increased[I] emissions of NOX. I grew up in Southern California in the 1960's and '70's and remember the brown cloud and the sore throats and tight chests from it. It's no fun using your lungs as a nitric acid factory. Just bringing up the point that there are always two sides to every argument but logic doesn't always dictate the winner.

The driving public and consumer are just low lying fruit with respect to how the EPA imposes its rules and regulations. If you look at the big picture, ocean shipping probably contributes more to global air pollution in one day than all automobiles driven in the United States in an entire year. Typical ocean transports are virtually unregulated with respect towards exhaust emissions and they use the worst fuel imaginable for propelling their loads of freight from mainland china to your local Wal Mart. Most of the ships fire their boilers with 'bunker oil'. The bottom of the refining tree residue that unusable for anything else because of sulphur content, mercury, etc. Burning tires probably pollutes less than burning 'bunker oil'.

Even though the EPA Link was simplified for public understanding, it made it clear that the problem was a photochemical interaction of hydrocarbons and NOx to produce ozone. The ozone comes from the Nox.

With the much smaller population of people and vehicles in the 60s and 70s you should have first hand knowledge of what happens on a sunny day in the AQMD (Air Quality Management District - the Los Angeles Basin) region seeing how you lived here. There is now over double the population of people and vehicles and the air is far better. I don't know how you continue to knock emissions efforts when the AQMD basin is a prime example of success.

And a little goes a long way. And it is cumulative. Each person in a small way contributes. Our business has been impacted not just in the vehicles we operate, but in the paints that we use, the cutting fluids the CNC machines use, down to the lighter fluids "forced" on us during company picnics. Southern California is just a microcosm of the rest of the world - too many people in too small of a place.

The Earth is soon to be in the same situation with the pollution contributions of over 7 billion sources great and small overwhelming the ability to absorb the output. The ground level pollution created in China is now detectable on the United States western shores. Our pollution ends up in western Europe and theirs goes . . . well you get the picture.

EPA is not perfect, but it has had tremendous success within it's jurisdiction and thus has set an example that is to be followed by other countries. The implementation of strict Euro6 standards are just an example. The Chinese governmental efforts are looking to the EPA for guidelines. Even the container ships you mention are coming under scrutiny as the Low Hanging Fruit is picked and more pollution cutbacks are sought. But, that is a question that is as much international politics as it is simple technology.

[RustyLugNut]

Originally Posted by TheGrimMechanic

. . . .
Aerodynamic mods are pretty much out of the question since the vehicle has the frontal profile of a barn door to begin with and it frequently gets used off-road.
. . .
t!

Our trucks are so poor aerodynamically, that simple and small changes can be gratifyingly effective. The Ford EcoBoost is not just all about the engine. The lighter frame helps. And the small aero tweeks help too. I am just pointing out how small changes such as a chin spoiler, an aero bed cap and active engine cooling shutters could put you well over your target.

[TheGrimMechanic]

Originally Posted by RustyLugNut

Even though the EPA Link was simplified for public understanding, it made it clear that the problem was a photochemical interaction of hydrocarbons and NOx to produce ozone. The ozone comes from the Nox.

With the much smaller population of people and vehicles in the 60s and 70s you should have first hand knowledge of what happens on a sunny day in the AQMD (Air Quality Management District - the Los Angeles Basin) region seeing how you lived here. There is now over double the population of people and vehicles and the air is far better. I don't know how you continue to knock emissions efforts when the AQMD basin is a prime example of success.

And a little goes a long way. And it is cumulative. Each person in a small way contributes. Our business has been impacted not just in the vehicles we operate, but in the paints that we use, the cutting fluids the CNC machines use, down to the lighter fluids "forced" on us during company picnics. Southern California is just a microcosm of the rest of the world - too many people in too small of a place.

The Earth is soon to be in the same situation with the pollution contributions of over 7 billion sources great and small overwhelming the ability to absorb the output. The ground level pollution created in China is now detectable on the United States western shores. Our pollution ends up in western Europe and theirs goes . . . well you get the picture.

EPA is not perfect, but it has had tremendous success within it's jurisdiction and thus has set an example that is to be followed by other countries. The implementation of strict Euro6 standards are just an example. The Chinese governmental efforts are looking to the EPA for guidelines. Even the container ships you mention are coming under scrutiny as the Low Hanging Fruit is picked and more pollution cutbacks are sought. But, that is a question that is as much international politics as it is simple technology.

I don't disagree with the original principles of the EPA. It's my opinion that what has happened over the years is that the EPA has been turned into a political tool and doesn't have the best interests of the country as one of its core values. I agree that there is some success' but recently it's gone overboard in some areas. My complaint don't entirely center on the EPA itself but also the rules it creates and leave up to the states to define or enforce or the unreasonable burdens placed on manufacturers and even the general consumer. Here are a few examples (albeit not related to the original intent of this post);
In California (I know, NOT the Federal EPA, but the policies started here many times find their way into EPA rules), Because of the concerns over VOC's, windshield washer solvent for your windshield containing ANY amount of methanol (or other type of alcohol) is banned UNLESS you live in a county where average wintertime low temperatures are below freezing. Another rule that originated in California and had been adopted by the EPA are the new emissions stands for small engines (i.e., lawn mowers, etc.) I honestly believe that rulemaking like this is an irresponsible waste of (administrative) resources and only serve as a distraction from other bigger sources of air pollution that are protected by political influence. I understand what you mean about improvements in small degrees but there are still a lot of gross polluters out there that have been getting a free pass for MUCH too long. I have a set of RR tracks not far from my house. I see Union Pacific locomotives several times a day with untreated exhaust. I have a small rail yard behind my house and I talk with the RR employees. Even the locomotives that are brand new don't have any emissions controls. Manufactured by General Electric (one of the big players in trying to have coal fired power shut down so they can sell more natural gas fired generation equipment), and EMD (Electro Motive Diesel, owned by GM). And then the railroads owned by Berkshire Hathaway (Warren Buffet). Why are they still allowed produce prolific amounts of NOX? Why is the EPA concerning itself with my lawn mower and not the freight trains behind my house? Pretty sure the 10 trains a day that pass through my county do more to pollute the air here than all of the lawn mowers in the county produce in a year. The EPA is more about image and perception any more than doing any meaningful work towards keeping the environment clean. Another example of an unnecessary burden is the forced use DEF (Diesel Exhaust Fluid) on Diesel powered vehicles. It's only good in the sense that it has allowed manufacturers to eliminate or reduce EGR and the maintenance problems associated with it and return some lost performance and fuel economy, but with one painful catch.....if your DEF tank runs out or the level sensor malfunctions, your vehicle shuts down. Your catalytic converter fails? Your car keeps running. Your EGR valve stuck shut? Your car keeps running. Your evaporative emissions purge valve sticks open? Your car keeps running. All of these emissions subsystems can and do fail and when they do, the driver is simply informed with a check engine light. This asinine requirement that your vehicle is disables if the DEF tank run dry was a mandatory requirement by the EPA to the manufacturers as a condition of letting them use DEF/SCR catalysts. The only other option to DEF/SCR is NOX absorber technology and it still hasn't matured enough to be viable in the heavy duty truck industry. The amount of EGR alone required to satisfy EPA rules makes the vehicles unusable and unable to meet the mandatory EPA emissions system warranty at best. Same things goes for DPF and the associated regeneration process that purposely burns fuel in the exhaust producing NO usable power for motivation. And again, the de facto (solely because the manufactures are forced to do this to protect the emissions warranty on the hardware) mandatory requirement by the EPA to cause a vehicle to become disabled because of a failed emissions device. Technology like DPF and DEF/SCR are forced on the public because there is no better alternative. And the reason for this is because the EPA creates the rules with no regard to the viability of existing technology. The philosophy of the EPA is 'Make the rules and the technology will follow'. There needs to be a better approach. If you look at the evolution of emissions systems beginning from the early 1970's on, you can see what the result of this has been. For the first 15 years they were horrible, subject to drivability problems and most of the time disabled by the owners and (illegally) by repair shops out of necessity. So what was the net effect of forcing the auto manufacturers to adopt immature technology? 15 years of horribly engineered automobiles that polluted nearly as much as their predecessors. It wasn't until the widespread adoption of feedback fuel injection systems in the late 1980's that any real impact on exhaust emissions affected air quality were made. So now, with respect to diesel vehicles built since 2007, we are going through the same thing all over again. Owners disappointed with dealing with the headaches of DEF/SCR and DPF are simply disabling these systems at great cost. I don't have the answer but there has to be a better way. I don't do the things I do to my vehicle because of a sense of rebellion against the government or EPA. I do it solely for economic reasons and in the eyes of some people, that makes me a criminal no different than a bank robber.

[2000mc]

Typically def systems restrict after warnings and going down through stages. The alternitve would be not allowing the engines at all, or implementing emmision inspections now, or after everyone is swimming in smog. Where there is emmision testing, the check engine light will indirectly stop you, it just takes up to a year. Who knows, in a few years manufacturers may have to start shutting down gas engines with emmision faults as well

[oil pan 4]

That's why you pull the DPF, disable or remove the EGR and reprogram the computer to run like an actual diesel engine once the warranty is up or nearly up.
Every one who has deleted this garbage is reporting over 50% higher fuel economy.

If you don't live in or visit a smog problem area then there is no reason to have your vehicle armed with fuel economy murdering extreme NOx eradication equipment.

As far as EGR on gas engines, it usually helps improve fuel economy. But as with most things vehicle related, there are few if any one size fits all, or any one mod that will return the same result on everything.

[oil pan 4]

Originally Posted by 2000mc

Typically def systems restrict after warnings and going down through stages. The alternitve would be not allowing the engines at all, or implementing emmision inspections now, or after everyone is swimming in smog. Where there is emmision testing, the check engine light will indirectly stop you, it just takes up to a year. Who knows, in a few years manufacturers may have to start shutting down gas engines with emmision faults as well

They could ban diesel engines. Then tractor trailers would be getting like 2 or 3mpg.
Fuel consumption on hard working heavy movers would go from barely reasonable with diesel to catastrophic with gasoline.