Picking up right where we ended, we’re traveling back to 1998 for a check out all the backward and forward that occurred in between Ford and Dodge at the turn of the century. After the 7.3 L Power Stroke topped the P-pumped 12-valve Cummins’ 215hp and also 440 lb-ft of torque with its very own 225hp and 450 lb-ft ranking, Dodge answered midway via the ’98 version year with the release of the 24-valve 5.9 L ISB. With producers in a race to satisfy tightening up NOx exhaust requirements whilst remaining in advance of the competitors, the VP44-fueled 24-valve Cummins supplied Dodge exactly what it needed to prosper at both. The brand-new Cummins, readily available starting with ‘98.5 Rams, belted out 235hp as well as 460 lb-ft, offered it was ordered with the NV4500 five-speed handbook behind it. Striking back, Ford integrated the launch of its overhauled 7.3 L Power Stroke in conjunction with the launch of its brand-new Super Duty truck line in the first quarter of 1998. Currently with an intercooler, a wastegated turbocharger, split-shot injectors, greater voltage IDM and an electrical fuel pump, Ford’s Navistar-built V8 ended up being the initial diesel in the pickup segment to get to the 500 lb-ft limit.
Nonetheless, by January of 2000 Dodge was ready to test Ford one more time, and after wringing one more 10hp and 45 lb-ft of torque out of the ISB, 2001 model year Ram 2500 as well as 3500s could be purchased with the very first high result Cummins ever before provided. Behind the scenes, General Motors and also partner Isuzu remained in the procedure of settling what would end up being not only a game-changer as well as technical marvel in the domestic truck market, yet the General’s path back to the top: the 6.6 L Duramax. While Cummins didn’t transform the wheel, in a manner of speaking, with the ISB Cummins, it did revamp the cast-iron block for a more powerful foundation. Though it would certainly keep the same forged-steel poles as the 6BT, it would see upgraded, lower compression cast-aluminum pistons, a revised camshaft with wider lobes and also longer press tubes. For boosted lubrication, a much more efficient oil pump was employed, which supplied an added 10 psi of oil stress at any type of engine speed. The main power ranking for the 5.9 L ISB was 235hp at 2,700 rpm as well as 460 lb-ft at 1,600 rpm when optioned with the NV4500 five-speed guidebook transmission.
Engines coupled with the 47RE four-speed automatic were de-rated to 215hp at 2,700 rpm as well as 420 lb-ft at 1,600 rpm. The entirely redesigned cast-iron cyndrical tube head included four overhanging valves per cylinder, with two shutoffs activated at the same time thanks to using crossover bridges. The 24-valve head likewise included 60-ppi valve springs, 6 bolts per cylinder, situated each injector in the facility of its particular cylinder as well as the thermostat housing place was cast right into the head itself. A one-piece reusable valve cover replaced the six person, modular covers used on the 6BT. With the 5.9 L Cummins breathing easier thanks to the added valves, throttle response was a lot enhanced. To match the brand-new place of the injectors within the head and optimize exhausts, the fuel dish was centrally located and especially larger than what was made use of on the 12-valve piston. Still cast from aluminum, all pistons included a ni-resist insert for the leading ring for maximum wear and also deterioration resistance. The top piston ring area can be moved more detailed to the top of the piston or reduced, depending upon the application (keep in mind, Cummins made the 5.9 L for several consumers, not just Chrysler).
In order to equal ever-tightening discharge criteria, executing electronic controls on the Cummins was inevitable. For the 5.9 L ISB, the online regulated Bosch VP44 was chosen for its capacity to offer more exact control over gas distribution, in addition to 23,200 psi shot stress ability. The VP44 is a cam-driven, radial piston pump with 3 interior pumping bettors and also is timed to the engine. Using its integrated computer system (coined the PSG), it’s entrusted with differing the injection timing, pressurizing the low-pressure gas it receives from the lift pump as well as regulating gas quantity. The injectors it feeds diesel to are still mechanical, yet their pop-off stress is considerably higher than what was found on the 6BT injectors (4,500 psi). From the manufacturing facility, an electric Carter lift pump was responsible for providing fuel to the VP44 injection pump. Placed on the motorist side of the block, gradually this lift pump would experience a relatively high failing rate, mostly as a result of its constant direct exposure to vibration.