In an effort to stay ahead of GM at the time, but more importantly also gain back the ground lost with the release of the 5. With hard parts like forged-steel connecting rods and six head bolts per cylinder, the heavy-duty makeup of the 7. Twenty-five years later, the method of injection employed on the 7.
This and much more helps explain why Navistar built nearly 2 million of them. Find out all you need to know about the time-tested, revered workhorse that is the 7. Producing hp at 3, rpm and lb-ft of torque at 2, rpm when it debuted, the 7. Although it shared the same displacement as its predecessor, the 7. The connecting rods were beefier, the crankshaft had bigger mains, direct injection was employed, six bolts were utilized per cylinder to anchor the heads to the block and higher pressure fueling was electronically and precisely controlled for more power output and cleaner emissions.
After the test-run of powdered metal rods, Navistar reverted back to forged-steel units in order to use up the remaining inventory on-hand at the manufacturing plant.
The engine serial breakdown for forged vs. Forged rods are capable of surviving rwhp and tend to bend rather than break, while those with the weaker powdered metal units which generally break rather than bend are advised to stay at or below rwhp. Of all the advancements to debut on the 7. Direct injection means that fuel is sprayed directly on top of the piston the combustion chamber on the power stroke no pun intended.
No pre-combustion chamber exists as it does on IDI engines. Each cast-aluminum 7. For the type of head-to-block sealing seen in commercial duty applications, the 7.
By comparison, its IDI predecessor featured five head bolts per cylinder and its successor the 6. The six-bolt arrangement makes the 7. Above, a ,mile 7. At the heart of the hydraulically-activated HEUI injection system lies this component: a fixed displacement axial-piston pump called an HPOP or high-pressure oil pump. It made hp and lb ft of torque, and was believed to be free of the problems that plagued the 6. However, it never really shook off all the demons from its predecessor.
The reliability was improved over the 6. In addition, the 6. The 6. Not only was this a huge risk for Ford, it was an expensive one: Ford had to assume production of one of its best-selling engines. However, many truck enthusiasts will tell you that it was well worth the risk for Ford. In , the Ford Super Duty began using the 6. Initially, it produced hp and lb ft. However, just one year later, Ford gave it a new turbo, which gave the 6.
In , even more changes bumped the 6. However, the peak torque increased to - get ready for this- - lb ft. Would it escape the reliability woes that plagued the two previous generations of Power Stroke? At first, predictions were guarded as early engines suffered from premature turbocharger failures.
However, that problem was quickly solved, and the 6. Add the fact that the 6. Have we hit peak diesel? We learned this year that the new Ford F will eventually receive a 3. As such, we can expect it to make around hp and around lb ft of torque, in a package that will get at least 30 US MPG on the highway.
But will this V6 ever achieve the same commercial success as its V8 forefathers? Adjustments were made also every year to the 7. One major difference between the 7.
IDI engines literally refers to engines that utilize indirect injection. In those engines, fuel is injected into a pre-combustion or swirl chamber, where fuel mixes with air before it enters the actual combustion chamber.
Instead of using an fuel injection pump to pressurize the fuel for the injectors, the 7. This high pressure oil pump is gear-driven and is a fixed-displacement design. All 7. This swash plate determines oil output of the HPOP.
Early 7. This gives late models an advantage because it provides greater oil volume, giving these engines the ability to support higher performance modifications more easily. The HPOP on 7. Instead, it sends oil to the injectors. This pressurized oil then enters the injectors where it is used to pressurize fuel up to 21, psi.
Over time, the High-Pressure Oil Pump can provide less than adequate performance. This can result in injector starving which leads to reduce power, lower fuel economy, and lesser reliability. Even stock trucks can benefit! This makes them one of the best 7. This occurs when the poppet valve opens, allowing high-pressure engine oil to enter the injector.
This places pressure on the fuel and when pressure gets high enough, fuel is injected to the combustion chamber through the injector nozzle. The Power Control Module is the main computer that controls the direct fuel injection process. The PCM controls fuel injection events by telling the IDM when, and for how long, electronic pulses need to be sent to the injector solenoids. When these solenoids get this pulse, volts, it releases the poppet valve, beginning the fuel injection and pressurization process inside the injectors.
The Map sensor helps the PCM determine engine load and how much fuel is needed. The Injector Drive Module, or IDM, is responsible for sending electrical current to the injector solenoids to open the poppet valve.
This allows pressurized engine oil to enter the top of the injectors which is then used to pressurize the fuel for combustion. Bad Injector Drive Modules are often the culprit behind poor running trucks.
Common symptoms of a bad 7. Another very positive 7. Instead of supplying an injection pump with a steady stream of fuel, this lift pump sends fuel directly to the cylinder heads instead, to later be used by the injectors. Two different fuel lift pumps are used on the 7. Early models, , utilize a cam-driven mechanical lift pump. While both lift pump systems are adequate on stock trucks, aftermarket lift pump systems can still provide better performance and better fuel filtration.
Three different Fixed Geometry Turbocharger configurations are used in the 7. OBS models, No intercooler is present on early, OBS models. In , the TP38 turbocharger was updated.
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