Diesel Definitions - Dictionary

2.6 Class:
Refers to a sled pulling class in which only a single turbo can feed the engine, and its inducer must measure no more than 66 mm (2.6 inches) 3.0 Class:
Refers to a sled pulling class in which only a single turbo can feed the engine, and its inducer must measure no more than 76 mm (3.0 inches); military or semi axles, aftermarket transmissions, and transfer cases are typically allowed, but stock frames are usually mandatory 4-Pin Trailer Plug:
Transfers the tow vehicle’s 12-volt electrical system to the trailer, so brake lights, marker lights, and turn signals work; most common on older vehicles or vehicles with low towing capacities 7-Pin Trailer Plug:
Transfers the tow vehicle’s 12-volt electrical system to the trailer, so brake lights, marker lights, and turn signals work; standard on heavy-duty trucks A/R:
Stands for Area/Radius (the exhaust housing size of a turbocharger), either measured in A/R, or cm2 Air Intake:
The air tube and filter package that’s mounted in front of the air inlet of a turbocharger   |   Air Intake Billet:
A process that involves milling a part out of one solid chunk of material Biodiesel:
A type of diesel fuel made from blending organic-based diesel with petroleum-based diesel, along with other additives Boost:
A measure of the amount of manifold pressure inside the engine; boost is normally measured in pounds per square inch (psi) above atmospheric pressure CAC: Charge Air Cooler (see: Intercooler) Cetane:
A rating for diesel fuel based on the time it takes the fuel to develop cylinder pressure after it’s injected Class V Hitch:
A receiver hitch rated for towing in excess of 10,000 pounds and more than 1,200 pounds of tongue weight; other lesser ratings include the I, II, III, and IV classes Coal:
Diesel smoke or soot, usually used as a slang term Common-Rail:
An injection system composed of a main pump and a common line to the injectors. In this arrangement, the injectors (rather than the injection pump) handle injection events Compound Turbo:
The turbo arrangement of having a smaller turbo drive a larger turbo (exhaust side) while the larger turbo draws atmospheric air and compresses it into the smaller turbo (intake side)   |   Compound Turbo Compressor:
The intake side wheel and housing of a turbocharger CP3:
A Bosch pump designed for common-rail injection systems, most notably found in ’01 to ’10 LB7, LLY, LBZ, and LMM Duramax diesel engines Cummins:
Manufacturing engines and related power systems, Cummins Inc., is a worldwide corporation known most often in the automotive industry as the manufacturer of the engines found in heavy-duty ’89 to ’13 Dodge and Ram pickups DEF:
Diesel Exhaust Fluid; a urea-based solution used in conjunction with an SCR system to reduce emissions; DEF is a mixture of 32.5 percent automotive-grade urea and 67.5 percent de-ionized water Direct Injection:
A diesel fuel system that injects fuel directly onto the top of the piston without any type of prechamber DPF (Diesel Particulate Filter):
A filter that captures particulate matter so that it is not expelled into the atmosphere   |   DPF (Diesel Particulate Filter) Drive Pressure:
The amount of pressure on the exhaust side of the engine, pre-turbocharger
Dual Fuelers:
The slang term for a common-rail diesel engine that utilizes a second (twin) high-pressure fuel pump   |   Dual Fuelers Duramax:
A 6.6L V-8 diesel engine option found in ’01 to ’13 GMC and Chevrolet fullsize trucks and vans, produced as a joint venture between Isuzu and GM ECM:
Engine Control Module; a computer that takes inputs from various sensors and has the basic overall job of controlling the engine’s operation EFILive:
A tuning tool for common-rail Cummins and Duramax engines that allows access to the vehicle’s factory programming so changes can be made to add power and increase fuel economy EGR cooler:
A radiator-style cooler designed to reduce the temperature of exhaust gases before they are re-injected into the engine’s intake tract EGR:
Exhaust Gas Recirculation; EGR is a system that redirects exhaust gases back into the intake tract to be re-introduced into the combustion process; helps to limit NOx emissions EGT:
Exhaust Gas Temperature; EGT is used as a measuring tool to define a point where a diesel engine can be reliably operated without harming parts; safe EGT (pre-turbo) is 1,200 degrees sustained, 1,400 degrees for short bursts, and 1,600 degrees for a few seconds Exhaust Brake:
A valve mounted in a diesel engine’s exhaust stream that’s used to create added exhaust pressure and increase engine braking; helpful for slowing large loads on steep downhill grades FICM:
Fuel Injection Control Module; this computer is used to control the firing events of the injector Fifth-Wheel:
A type of trailer hitch incorporating large flat plates and a locking pin; used for towing large amounts of weight   |   Fifth-Wheel Fire Ring:
A small steel ring that’s inserted into a machined groove in either the head or block (or both) to help contain excessive cylinder pressure due to increased power levels; used to prevent a blown head gasket Fuel Only:
Slang term, meaning no nitrous, propane, water-methanol, or other injectables Gooseneck:
A large, ball-type hitch, mounted in the bed of a truck over the rear axle, used for towing large amounts of weight; allows more trailer movement over uneven terrain Governor Spring:
A spring or set of springs used to control peak injection pump rpm, effectively giving the engine a “redline” GCWR:
Gross Combined Weight Rating; the maximum allowed weight of a tow vehicle, all of its passengers and cargo, and a trailer GVWR:
Gross Vehicle Weight Rating; the maximum allowed weight of a vehicle (which indicates its payload capacity) Head Studs:
Aftermarket stock-sized or oversized studs that replace the head bolts for more clamping force; used to prevent a blown head gasket HEUI:
Hydraulic Electronic Unit Injector; used on 7.3L and 6.0L Power Strokes as well as other medium-duty engines; an HEUI injector uses pressurized oil to fire the injector HPOP:
High-Pressure Oil Pump; found most commonly on 6.0L and 7.3L Power Strokes; the HPOP receives oil from the crankcase, and through the IPR, high-pressure oil is then fed to HEUI injectors ICP:
Injection Control Pressure; the pressurized oil value in the oil rails of an HEUI-equipped engine; typically in a range of 450 to 3,000 psi, or more IDI:
Indirect Injection; an IDI engine injects fuel into a prechamber in the cylinder head before it enters the combustion area on the piston IDM:
Injector Driver Module; sends a precise, electronic current to the injector solenoid in a 7.3L Power Stroke; called an FICM on the 6.0L Power Stroke Injection Pump:
A high-pressure pump used to pressurize fuel and send it to the injectors Injector:
A device consisting of valves, springs, a nozzle, and various passages that is actuated to spray a metered amount of fuel into a prechamber (IDI) or combustion chamber (DI)   |   Injector Intercooler:
A series of fins and tubes in a radiator-like design, used to cool off the air exiting the turbocharger, thus increasing overall efficiency by creating a denser air charge IPR:
Injection Pressure Regulator; dump valve that sits on the HPOP outlet of an HEUI engine and is responsible for creating pressurized oil the injectors can use Lift Pump:
A mechanical or electric supply pump that sends fuel from the tank to the injection pump Limited Slip:
A type of differential that adds traction by equalizing the output of each axleshaft through clutches, gears, or cones; these differentials are more streetable because they still allow some level of differentiation between the driveshafts to occur Lockup Torque Converter:
A torque converter that incorporates a clutch or multiple clutches to lock the converter solid to the engine, eliminating any slippage Locker:
A locker is a type of differential that locks the two axleshafts together, ensuring both wheels get the same amount of power from the drivetrain Nitrous:
Also known as NOS, nitrous is short for nitrous oxide, an oxygen-bearing gas that can be injected into a diesel engine to increase the engine’s power dramatically   |   Nitrous NOx:
Nitrogen Oxide; a tailpipe emission that is thought to be hazardous to the environment O-ring:
Stainless steel wire that’s planted into a groove cut around the combustion area of the cylinder head(s) and provides better sealing of the combustion event OBS:
Short for “Old Body Style,” normally in reference to ’94½ to ’97 Fords P-pump:
Bosch P7100 injection pump; most commonly found on ’94 to ’98 Dodge Rams Particulate Matter:
Airborne pieces of carbon, also known as smoke or soot   |   Particulate Matter PCM:
Powertrain Control Module; mostly found on Ford pickups, the PCM integrates engine and transmission functions Piezo Injector:
A common-rail fuel injector that’s activated using very-fast-reacting piezoelectric crystals; these injectors use electricity to precisely introduce fuel into the combustion chamber and can open and close up to seven times during a single combustion event Power Stroke:
A line of International diesel engines found in Ford trucks from ’94½ to ’10, the Power Stroke was available in ’94½ to ’03 (7.3L), ’03 to ’07 (6.0L), and ’08 to ’10 (6.4L); the ’11 to present 6.7L is an in-house Ford design Programmer:
Also known as a tuner, this is a device that changes the air, fuel, timing, and shifting strategies of an electronically controlled engine Pulse Width:
The length of time of an injection event, also known as duration or injector “on time” Rail pressure:
The amount of fuel pressure in the rail of a common-rail injection system Rolling Coal:
Slang term used to describe the act of blowing black smoke S-Series Turbochargers:
A BorgWarner turbocharger designation based on frame and bearing size; most commonly used are S300s and the larger S400s SCR:
Selective Catalytic Reduction; an emissions system designed to reduce NOx through the use of DEF (urea) injection; SCR works by injecting a small amount of DEF upstream of the catalyst, when the DEF enters the exhaust stream, it turns to ammonia and works with the SCR catalyst, turning NOx to nitrogen and water Spool up:
The stage when a turbocharger is building boost but has not yet reached maximum boost Stack:
Also known as an exhaust stack; an upward-exiting exhaust usually mounted through the bed, or through the hood   |   Stack Super Stock:
Refers to a sled pulling class in which multiple turbochargers can feed the engine, but it limits competitors to two stages; tube-chassis frames, military or semi axles, and aftermarket transmission and transfer cases are also allowed T3:
The most commonly used turbocharger mounting flange in early Cummins 5.9L applications and other pickup truck diesel applications TCM:
Transmission Control Module; on most pickups, the TCM is integrated with the ECM to control transmission shift strategies TDI:
Turbocharged Direct Injection; a branding of Volkswagen’s Group I-4 and V-6 turbodiesel engines Traction Bar:
A long rod (usually steel) mounted between the frame and the rear suspension to prevent axlewrap   |   Traction Bar Turbine:
The exhaust-side wheel and housing of a turbocharger Turbo lag:
The time it takes for a turbocharger to start generating measurable boost Turbocharger:
Exhaust gas-driven compressor that is used to force air into an engine and increase the intake pressure above atmospheric   |   Turbocharger Up-pipe:
The exhaust pipes leading from the exhaust manifolds to the turbocharger Urea:
A common agricultural fertilizer made from natural gas and one of the two ingredients in diesel exhaust fluid. VGT (Turbo):
A variable-vane, variable-geometry, or variable-nozzle turbocharger; the vanes or nozzles are used to reduce the effective A/R, improving response and spool-up VP44:
An electronic Bosch rotary pump, most often found on Cummins engines in ’98 1⁄2 to ’02 Dodge Ram trucks Wastegate:
A valve mounted in the exhaust system designed to release excess exhaust pressure Water-Methanol Injection:
A high-pressure system that injects water or a water-methanol mix into a diesel engine for more power, improved efficiency, and cooler EGT Work Stock:
A sled pulling class typically allowing factory-appearing turbocharger rules, or having a maximum turbo inducer size rule of 2.5 inches (63.5mm) Learning about diesels? Keep this story forever!