View source for Detroit Diesel V8 engine

{{Infobox automobile engine
| image = Detroit Diesel V8 engine front.jpg
| name = General Motors–Detroit Diesel V8
| aka = 
| manufacturer = General Motors
| configuration = 90° [[V8 engine|V8]]
| production = 1981 (limited)<br/>1982–2002
| predecessor = [[Oldsmobile Diesel engine#LF9|Oldsmobile Diesel LF9]] {{Convert|350|cuin|L|1|abbr=on}}
| successor = [[Duramax V8 engine]]
| bore = {{Unbulleted list|6.2 L: {{Convert|3.98|in|mm|1|abbr=on}}|6.5 L: {{Convert|4.06|in|mm|1|abbr=on}}}}
| stroke = {{Unbulleted list|6.2 L: {{Convert|3.8|in|mm|1|abbr=on}}|6.5 L: {{Convert|3.82|in|mm|abbr=on}}}}
| displacement = {{Unbulleted list|{{Convert|379|cid|L|1|order=flip|abbr=on}}|{{Convert|395|cid|L|1|order=flip|abbr=on}}}}
| length = 
| diameter = 
| width = 
| height = 
| weight = 
| block = [[Cast iron]]
| head = Cast iron
| valvetrain = [[Overhead valve engine|OHV]] 2 valves × cyl.
| turbocharger = [[BorgWarner]] GM-X series (optional on 6.5L only)
| fuelsystem = 1993 and older: Mechanical rotary pump<br/>1994 and newer: Electronic rotary pump
| fueltype = [[Diesel fuel|Diesel]]
| oilsystem = 
| coolingsystem = [[Radiator (engine cooling)|Water-cooled]]
| power = {{Convert|130-215|hp|kW|0|abbr=on}}
| specpower = 
| torque = {{Convert|240-440|lbft|Nm|0|abbr=on}}
| compression = 21.5:1, Marine 18.0:1
| emissions control = [[Exhaust gas recirculation|EGR]] and [[catalytic converter]]
| redline = 3,600
| idle = 550 ± 25
}}

The '''General Motors–Detroit Diesel V8 engine''' is a series of [[Diesel engine|diesel]] [[V8 engine]]s first introduced by [[General Motors]] for their [[Chevrolet C/K|C/K pickup trucks]] in 1982. Developed in collaboration with GM subsidiary [[Detroit Diesel]], the engine family was produced by GM through 2002, when it was replaced by the new [[Duramax V8 engine|Duramax]] line. AM General's subsidiary General Engine Products (GEP) still produces a military variant of this engine for the [[HMMWV]].<ref name=autogenerated1>{{Cite web|url=http://www.amgeneral.com/vehicles_gep_productinfo.php|title=General Engine Products :: Product Information |publisher=AM General|accessdate=2010-12-02|url-status=dead |archiveurl=https://web.archive.org/web/20080919231511/http://www.amgeneral.com/vehicles_gep_productinfo.php|archivedate=2008-09-19}}</ref>

The General Motors light-truck 6.2L and 6.5L diesel engines were optional in many 1982 through 2002 full-size GM pickups, SUVs, and vans. They were also available in [[motor home]]s. The engine was standard on [[AM General]]'s military [[HMMWV]], civilian [[Hummer H1]], and the 1980s GM military [[Commercial Utility Cargo Vehicle]].

==6.2L==
[[File:1987 AM General HMMWV model M1045 military at 2017 Rockville Maryland show 10of12.jpg|thumb|left|6.2L fitted to a 1987 HMMWV]]
The original {{Convert|379|cuin|L|1|abbr=on|order=flip}} diesel V8 was introduced in 1982 for the [[Chevrolet C/K]] and was produced until 1993. The 6.2L diesel emerged as a high-fuel-economy alternative to the V8 gasoline engine lineup, and achieved better mileage than Chevrolet's 4.3L V6 gasoline engine of the 1980s, at a time when the market was focused on power rather than efficiency. However, it was designed to easily install in place of the gasoline V8, using the same mounting and attachments for transmissions as all GM truck engines. Overall weight for the complete engine is slightly heavier than the [[Chevrolet big-block engine|7.4L/454 V8 big-block gasoline engine]]. There were about 300 6.2L diesel engines which were placed into 2-door cars in 1981, prior to official production. These were then given to the United States government and issued to various federal agencies and military branches. These were used as testbeds regarding long term fuel economy and reliability in cars.

===Applications===
* 1981 [[Chevrolet Impala]] Sport Coupe (only available with upgraded suspension)
* 1982–1993 [[Chevrolet C/K|Chevrolet/GMC C/K]] 10/1500, 20/2500, 30/3500
* 1982–1991 [[Chevrolet Suburban|Chevrolet Suburban/GMC Suburban]]
* 1992–1993 [[AM General]] [[Hummer H1]]
* 1982–1993 [[AM General]] [[Humvee|HMMWV]]
* GM version of the [[Commercial Utility Cargo Vehicle#General Motors|CUCV]]
* 1982–1993 [[Chevrolet van|Chevrolet/GMC G-series van]] 20/2500, 30/3500

===Specifications===
* Engine RPO codes: LH6 ('C' series, with [[Exhaust gas recirculation|EGR]] / [[Pressure regulator|EPR]]) and LL4 ('J' series)
* Displacement: {{Convert|379|cuin|L|1|abbr=on|order=flip}}
* Bore × stroke: {{Convert|3.98|x|3.8|in|mm|1|abbr=on}}
* Aspiration: Natural
* Compression: 21.5:1
* Injection: Indirect
* Horsepower and torque (at launch): {{Convert|130|hp|kW|0|abbr=on}} at 3,600&nbsp;rpm / {{Convert|240|lbft|Nm|0|abbr=on}} at 2,000&nbsp;rpm
* Horsepower and torque (final): {{Convert|160|hp|kW|0|abbr=on}} at 3,600&nbsp;rpm / {{Convert|285|lbft|Nm|0|abbr=on}} at 2,000&nbsp;rpm
* Horsepower and torque (US Army HMMWV model): {{Convert|185|hp|kW|0|abbr=on}} at 3,600&nbsp;rpm / {{Convert|330|lbft|Nm|0|abbr=on}} at 2,100&nbsp;rpm
* Redline: 3,600&nbsp;rpm
* Idle RPMs: 550 ± 25

==6.5L==
[[File:22nd Marine Expeditionary Unit (MEU) 140708-M-HZ646-077 (14425655210).jpg|thumb|right|22nd MEU marines extract a 6.5L V8 from a [[HMMWV]] (2014)]]
The {{Convert|395|cuin|L|1|abbr=on|order=flip}} version was introduced in 1992 to replace the 6.2. Most 6.5s were equipped with a turbocharger. This engine was never meant to be a power and torque competitor with Ford/International and Dodge/Cummins, but rather a simply designed workhorse engine that made credible power, achieved decent [[Fuel economy in automobiles|fuel economy]], and met [[emission standard]]s in [[Truck classification|half-ton trucks]]. The [[Duramax V8 engine|Duramax 6600]] replaced the 6.5 in light trucks beginning in 2001 and the C3500HD medium duty cab and chassis (replaced by the C4500 Kodiak/TopKick) and vans beginning in 2003, but the 6.5 (6500 Optimizer) is still produced by [[AM General]] for the [[Humvee|HMMWV]].

There are several GM 6.5-liter diesel engine production options. The turbocharged L56 ([[Vehicle identification number|VIN]] "S") was used in 1/2-ton and light-duty 3/4-ton. Heavy-duty 3/4-ton and 1-ton trucks used the turbocharged L65 (VIN "F") engine. The L56 is emissions controlled with [[Exhaust gas recirculation|EGR]] and [[catalytic converter]]s. The L65 engine has neither an EGR system nor a catalytic converter, but there is a soot trap on L65 engines that is often mistaken for a catalytic converter. GM was the first manufacturer to introduce an electronically controlled [[fuel injection]] system into a diesel pickup truck.<ref>{{Cite web|url=http://flashoffroad.com/Diesel/GM99Diesel/6_5LV8TurboDieselFeatures.htm|title=6.5L V8 Turbo Diesel L65 Truck: Features|website=flashoffroad.com}}</ref> The L49 (VIN "P") and L57 (VIN "Y") are both naturally aspirated engines. L57 is listed as HO or Heavy Duty. Additional [[Regular Production Option|RPO codes]] are LQM {{Convert|175|hp|0|abbr=on}} and LQN {{Convert|190|hp|0|abbr=on}}.

Changes were made by GM to the 6.5 in their light trucks for emissions or reliability improvement. The 1992–1993 model years used a 6.5-specific [[Stanadyne]] DB-2 mechanical [[injection pump]]. GM replaced the DB-2 with the electronic throttle DS-4 in 1994–2000 vehicles. In mid-1996, GM implemented a redesigned engine cooling system incorporating twin non bypass-blocking [[thermostat]]s and a {{Convert|130|U.S.gal/min|L/min|abbr=off|sp=us|adj=on}} water pump. This improved the flow through the block by 70–75% and flow to the radiator 7%.

===Applications===
Turbocharged:

*1994–1999 [[Chevrolet Tahoe|Chevrolet Blazer/Tahoe/GMC Yukon]] (2-door 4×4 models only) (light-duty)
*1994–1998 Chevrolet C/K 1500 and 2500 (light-duty)
*1994–1999 [[Chevrolet Suburban|Chevrolet/GMC/Holden Suburban]] (heavy-duty)
*1992–2000 Chevrolet/GMC C/K 2500 and 3500 (heavy-duty)
*2001–2002 Chevrolet/GMC C3500HD (heavy-duty)
*1996–2002 [[Chevrolet Express|Chevrolet Express/GMC Savana]] 2500 and 3500 (heavy-duty)

Naturally aspirated:
* 1994–1996 [[AM General]] [[Hummer H1]] (also used the turbocharged version)
* 1994–present [[AM General]] [[HMMWV]] (also used the turbocharged version)
* 1994–1996 [[Chevrolet van|Chevrolet and GMC G20 and G30]] vans (naturally aspirated)
* 1999–2005 Workhorse Custom Chassis (light- and medium-duty forward-control chassis): P42 Commercial, P32 Motorhome (also turbocharged on some versions)<ref>{{Cite web|title=Chassis Guide General Information|url=http://www.deserttruckservice.com/pdf%20folder/workhorse_chassis.guide.pdf|archive-url=https://web.archive.org/web/20160408234444/http://deserttruckservice.com/pdf%20folder/workhorse_chassis.guide.pdf|url-status=usurped |archive-date=April 8, 2016 |publisher=Workhorse Custom Chassis}}</ref>

===Specifications===
* Engine RPO codes: L49, L56, L57, L65, LQM, and LQN.
* Displacement: {{Convert|395|cuin|L|1|abbr=on}}
* Bore × stroke: {{Convert|4.06x3.82|in|mm|1|abbr=on}}
* Aspiration: Turbocharged (BorgWarner GM-X series). Also available naturally aspirated.
* Compression: GM early 21.3:1, GM late 20.3:1, AMG/GEP marine 18.0:1
* Injection: Indirect
* Horsepower/torque (lowest): {{Convert|160|hp|kW|0|abbr=on}} at 3,600&nbsp;rpm / {{Convert|290|lbft|Nm|0|abbr=on}} at 1,700&nbsp;rpm (naturally aspirated)
* Horsepower/torque (highest): {{Convert|215|hp|kW|0|abbr=on}} at 3,200&nbsp;rpm / {{Convert|440|lbft|Nm|0|abbr=on}} at 1,800&nbsp;rpm (turbocharged)
* Redline: 3,600 rpm

==Fuel system==
{{Listen|filename=Detroit62.ogg|title=Diesel 6.2L Exhaust|type=sound}}
The fuel system is a very simple design. A mechanical or electric fuel lift pump feeds a Stanadyne rotary [[distributor]] injection pump at low pressure. The distributor injection pump controls both metering, via an internal [[centrifugal governor]], and high pressure fuel delivery to the fuel injectors via internal precision hydraulic pumps. Near the top of the compression stroke, fuel is atomized at high pressure into a hemispherical Inconel prechamber in the cylinder heads using [[Bosch (company)|Bosch]] pintle and seat mechanical fuel injectors. This is called [[indirect injection]]. GM used fully mechanical DB2 series injection pumps on all military HMMWVs and 1982–1993 6.2s and 6.5s. From 1994 until end of production, GM used the electronically controlled Stanadyne DS4 series of injection pumps in its light trucks. A mechanical DB4 series injection pump can be found on some 6.5L [[Marine propulsion|marine engines]].

==Common problems==
*Main bearing web crack: In both 6.2L and 6.5L engines, this is reportedly fixed with a combination of improved higher nickel cast iron alloy and lower block re-design including, but not limited to, a [[main bearing]] girdle. These features are in the new-for-2007 AM General GEP P400 6500 Optimizer enhanced 6.5L diesel presently being sold to the U.S. government for the 6-ton armored HMMWV.<ref name=autogenerated1 />
*Crank failure: Related to age failures of the harmonic balancer, the vibration-dampened accessory drive pulley, or the dual-mass [[flywheel]].
*Pump mounted driver: Relates to thermal failures. The PMD is screwed to the DS-4 injection pump on the 1994–2002 6.5L diesel utilizing fuel flow to dissipate heat. The injection pump is mounted in the intake valley (a high heat area). The PMD contains two power transistors that should be cooled by proper contact with the injection pump body. If the pump is not precisely machined to make complete contact with the transistors via the silicone thermal gasket and paste, the PMD is improperly installed without the gasket or paste, the PMD is installed off center with the pump body, or corrosion develops on the mounting surface the PMD will overheat. Several companies manufacture an extension harness and heat-sink kits. These allow an owner or a mechanic to relocate the PMD away from the injection pump to a lower-heat environment or a place that can get more air flow.
*Cylinder head cracking: Higher-mileage 6.5 engines can exhibit stress related fractures in the cylinder head bowl. Stronger cylinder heads remedy this problem.
*Oil cooler line failure: Stock 1990s GM oil cooler lines are held together by a C-clip at the engine block and since the engine has no low oil pressure shutoff switch, if one clip fails, the engine loses its oil and seizes. Aftermarket oil cooler lines that utilize compression fittings rectify this.

==References==
{{Reflist}}

==External links==
{{Commons cat}}
* [http://www.motormayhem.net/2009/10/11/stanadyne-db2-fuel-injection-pump/trackback/ DB2 Injection Pump]

{{GM late engine timeline}}
[[Category:General Motors engines]]
[[Category:Detroit Diesel engines]]
[[Category:Marine diesel engines]]
[[Category:Diesel engines by model]]
[[Category:V8 engines]]