1998. This is a bit confusing for the uninformed. Officially there is no 1998 model year for the Heavy Duty Ford F-250-F-550 Series Pickup. This was the year that ford went to two different platforms for its trucks- The light duty F-150 and the New Super Duty series of heavy duty work truck available as the F-250 up to F-550. Diesels were not available in the light duty F-150. Where this conversation is about diesel, we will only focus on the Super Duty platform. So if there was no 1998 MY, what was available in 1998? You had a few options. You could buy a 1997 OBS truck(Old Body Style) or the All New Early 1999 MY(Model Year) Super Duty. There were however 1998 MY E-series vans with the Powerstroke diesel. The 1998 E-series had the same updated Powerstroke engine that the 1999-2003 Super Duty would get with the electric lift pump.
1999-2003. These are among the Best, most reliable and heavy duty pickup trucks ever made. Ever. The Crew cab can fit a family of 6 easily. Even if they are 6’6” tall! The cabin space is simply perfect. The drive train is nearly bullet proof save for the transmission. And the 7.3? Well it really became something special during these years. The 7.3 has proven to be exceptionally reliable, and nearly indestructible, so long as you are not trying to make 500hp with them. The truck was released in 1998 as a 1999 model, but there are really two generations of 1999. There is the Early 99, made prior to 12/98, and then the late 99. The differences are subtle, but many. On the engine the Turbo is smaller, the intake is smaller, the turbo pedestal is different, The HPOP is different, Suspension is different, and some of the interior options are different. The trucks are most easily identified by the location of the powerstroke badge. The early 99’s have the “V8 Powerstroke” badge on the Front fender, and the late 99-03 7.3 have the Powerstroke badge on the door. Generally speaking the late 99 trucks are more desirable to have, and the conversion process is slightly easier. In 2002 The Super Duty got clear headlights, a significant change in wiring and Gages, and finally ALL super Duty’s (except the Excursion) got a real Dana 60 Front differential instead of the half breed Dana 50. The engine remains unchanged.
Fuel Delivery. Beginning in 1998 with the E-series Van and in 1999 with the Super Duty trucks, Ford went with an electric lift pump and a deadhead fuel design. The path of fuel flow is from the tank, through the electric lift pump on the frame under the drivers seat, to the Fuel bowl in the engine valley, through a simple poppet regulator, and back to the tank. This causes the fuel bowl to pressurize, forcing fuel through the filter, and out the two fuel lines on the passenger side of the fuel bowl to the OEM fuel feed ports on the engine. One feeds to the Passenger side rear(cylinder 7), the other to the Drivers side front(cylinder 2). The opposite ends of the fuel ports that was used on the earlier years has been plugged off. That means that fuel is only fed to the engine, but never returns from the engine. Tidbit- Factory spec for the fuel pressure is 54psi plus or minus 3. Typically I see anywhere from 60-70 psi on most trucks. But remember from earlier, anything north of 50 and south of 100 is adequate. This fuel system design while simple, had it’s drawbacks as well. Mainly in that the firing order is [FONT='Verdana','sans-serif']1,2,7,3,4,5,6,8. If you remember from earlier, the cylinder arrangement on the drivers side is 2,4,6,8, and fuel is fed into the rail by #2. That puts #8 at the “dead” end of the fuel rail. It is getting what fuel is left over from the other cylinders. Then to further complicate matters is that #6 fires immediately before #8. So #6 is further robbing #8 for fuel. This leads to a constant state of fuel starvation for #8. There are a few ways to combat this problem. Ford, devised the so called “Long Lead” injector. This was a futile attempt at incorrectly solving the problem by modifying an injector with a longer filling time. It didn’t work. The aftermarket had some much more effective ways of dealing with this by either shimming the pressure regulator to increase fuel pressure therefore helping to overcome restrictions to flow and allowing more fuel to #8, or the more expensive but better option which was the regulated return. Fuel was fed all the way through the head, and pressure was regulated after the injectors, not before. This ensured a much more stable fuel pressure for ALL injectors and eliminated any starvation issues. This resulted in a much quieter engine, smoother idle, and some gain power, maybe as much as 15hp on an otherwise stock truck. One other issue that was well known was that the Ford fuel system was known for getting air into the fuel either from the fuel line seals between the pump and tank, or from the fuel pickup in the tank itself. This air would get trapped in the heads with nowhere to go but through the injectors. Fortunately the injectors on the 7.3 were very robust, and the fuel starvation or the air did not have any real detrimental effect on the life of the engine or injectors. There are plenty of bone stock 7.3’s with 500,000 miles or more on them. One other item of note that is really only for the horsepower junkies is that in 2001 Ford started using PMR process connecting rods instead of the Forged rods it had been using since 1994. Ideally the PMR rods have a higher tensile strength and greater hardness then the Forged rods, but they were also much more brittle, and when used with an unreinforced crankcase were more prone to breakage than the much more forgiving Forged rods. Rule of thumb is no more than 400hp with PMR’s, and up to 500hp with the Forged. [/FONT]
The End[FONT='Verdana','sans-serif']. 2003 would mark the last year that you could buy a Ford truck with the coveted 7.3 Powerstroke ending a highly successful 10 year run that helped make the Ford Super Duty the undisputed champion of Reliable Hard working trucks. Federal emissions regulations, and increasing HP/TQ demands in the marketplace dictated the need for a newer, smaller, more efficient, more powerful, and more emissions friendly engine. And in 2003, the all new high tech 6.0 Powerstroke was released, becoming one of the biggest black eyes Ford Trucks have ever known. [/FONT]
6.0 Powerstroke[FONT='Verdana','sans-serif']. This engine was the future of Diesels. High tech and High Power. The all new 6.0 had Four Valves per cylinder, A variable Vane turbo that could provide maximum boost off idle, smaller more efficient HEUI injectors operating at up to 26,000 psi, Pilot Injection that made the motor super quiet for a diesel. The block was a two piece design now with the crank being held in place by the two halves of the block ensuring an extremely strong and rigid bottom end. And finally the old 4R100, formerly the E4OD that has been around since the 80’s gets replaced with a modern 5 speed automatic made for diesel use, called the 5R110. The 5R110 was better in every way than the outgoing 4R100. These Transmissions had very few issues, if any. The same could not be said for the motor. [/FONT]
[FONT='Verdana','sans-serif']Pick your poison. International who designed the 6.0 had already been using them in their fleet fairly successfully. However the consumer light truck market was different than the commercial truck market. Ford didn’t dare release a new engine that couldn’t match or better the competitors HP and TQ numbers. And of course it had to be quieter as well. This required a higher RPM, a different turbo, and modified injectors from the original International design the meet the requirements. The engine had already been through substantial testing and validating, so changing a few items shouldn’t cause much problem. [/FONT]To get back on track, the injectors were one of the critical components for converting the 6.0. Many people and companies attempted to convert the 6.0 to run on oil, and failed. There were a few reasons for this. First the OEM fuel system has two filters- One on the Frame at the fuel pump also known as FCM, or Fuel conditioning module. This housed the primary fuel filter, fuel pump, thermal fuel recirculation valve, and water separation. From there the fuel traveled to the secondary filter bowl on the engine. This fuel bowl is similar in operation to that of the 7.3. There is a simple poppet valve regulator that pressurizes the fuel bowl to about 54psi forcing the fuel through the filter through two fuel lines and to the injector fuel rails. Except in this case the fuel is fed through the front of the engine using 12mm Banjo Fittings. There are fittings at the opposite ends of the fuel rails, but like the 7.3 they are plugged. This is still a deadhead fuel system, and again like the 7.3, on the drivers side the fuel is fed through the front, and deadheaded at the back, at #8 injector. The fuel starvation issue isn’t as bad since the fuel rails have a larger volume that better deal with the deadhead design. At least until you get into the higher horsepower applications. When trying to feed oil through the OEM fuel system filter plugging was a major problem. It is nearly impossible to keep enough heat in the oil for the oil to make it past both filters without waxing and eventual plugging. Then of course once the filters plug, switching back to diesel does no good. It is too late at that point. The engine loses fuel pressure, you are stuck, and there is a very likely chance your injectors are ruined from the low fuel pressure. There is only one way to successfully convert the 6.0 to run on 100% SVO with no problems. And that is a completely separate pressure based fuel system designed to handle the viscosity of the oil and ensure that the injectors never lose pressure. The DFA Vegistroke is the only vegetable oil conversion system currently that operates that way. And because of that we have converted hundreds of 6.0’s without issue. In fact we have some 6.0’s out with over 100,000 miles on oil already! Not all systems are the same when done correctly the 6.0 can run perfectly find on oil without creating problems not already inherent to the motor.
To recap- The 6.0 PowerStroke can be converted to run on oil successfully without more than normal maintenance or failures if done with a quality pressure based fuel system that will ensure the injectors never lose pressure. The system does not help prevent other engine issues such as EGR coking and sticking, head gasket issues, cylinder washing from bad injectors, etc.
The Rest Of the Truck. The chassis has not had a major overhaul since its introduction in 1999, however almost nothing remains unchanged. Even the frame itself is considerably different. However the exterior dimensions remain unchanged from 1999-2009. Why mess with perfection? In 2005 besides some pretty serious interior changes the Truck got a facelift with a new grill, bumper, and integrated crystal headlights/turn lamps. This look is in my opinion one of the best looking trucks Ford ever made. And the good news for those with older trucks is that these parts are a direct bolt on that can be done in a matter of a few hours. 2005 was the first year that the heavy duty trucks would get a coil spring front suspension that helped ride considerably and turning radius.
6.4 A new Era of Uncertainty. For 2008 model year Ford released the latest and LAST International designed motor- The twin turbo 6.4l common rail, piezo injector high tech motor. Even though the basic construction itself is the same as the 6.0, Everything that was an issue with 6.0 was addressed. First the fuel system. This would mark the first time that HEUI injection would not be used for the Powerstroke. The fuel system is now a common rail injection system using a first in the industry Piezo injector. These crystal based injectors have such a quick reaction time that they can be fired 5 times per combustion stroke!! The injection system is nothing short of sensational and completely different from the Cummins or Isuzu(Duramax) systems which both rely on CPS injection pumps and very similar style injectors. Other issues addressed besides the injection was the reputation for weak headgaskets. The heads were revised and headbolts were upsized from 14mm to 16mm and no longer hold the rocker arm fulcrum. The EGR cooler was significantly revised and more than doubled in size for cooler exhaust temps into the intake and less EGR failures. Due to the dual turbos AND variable vane the torque curve is incredible making over 500lb-ft from 1300 rpm to 3300 rpm. Reliability has been improved from last to on par with the others. In fact the 6.4 has had fewer issues than the new 6.7 Cummins engine.