8100 chevy vortec engine swap info

grumpyvette

Administrator
Staff member
below youll find a good deal of info on the 8100 vortec big block, the problem is that it was only in production for a rather limited time frame and performance parts available ar rather limited and fairly expensive, the good part is the engines can be occasionally found in salvage yards and don,t command a huge premium in cash like the performance 427-454-502 fourth gen bbc engines.
keep in mind you can generally build a standard fourth gen 496 displacement bbc engine buy installing a 4.25" stroke crank, in a 454 with a .060 over bore (the big block version of the 3.75' stroker crank in as 350 SBC with a .030 over bore, to build a 383)
496 VORTEC = 4.250" bore diam. x 4.37" stroke (2001 Vortec 8100, 8.1 liter)

http://www.raylarengineering.com/intake_manifold.html

https://www.youtube.com/watch?v=6qGrsEp_WxI

Part Numbers used for my swap: Keep in mind, my part numbers are for use with a manual transmission, mechanical throttle body and return type fuel system along with the G-van/Workhorse/Medium duty accessory brackets.

Part Number Description
52445253 A/C compressor
11516360 A/C compressor bolts
12581203 Belt tensioner
11516367 Belt tensioner bolt
12578330 Coolant Crossover
12571593 Coolant Crossover gasket
12575172 Crank Sensor
12575123 Dipstick
12570590 Dipstick tube
12559976 EGR Cover
12580673 EGR Cover gasket
12574560 Engine Cover
12567370 Engine Cover Ball Stud
12562957 Engine Cover Bracket
12562958 Engine Cover Bracket Stud
12582964 Flywheel
12563485 Flywheel bolts
EP381 Fuel pump
W0000393 HOUSING ASM - PCM
12580771 Idler on alternator bracket
213-298 Knock sensor - Drivers side
213-2829 Knock sensor - Passenger
12573337 Oil Cap
12573337 Oil Cap
12581140 Oil Fill Tube
11518950 Oil fill tube stud
12568356 Oil pump drive
12575055 RAIL KIT,M/PORT F/INJN FUEL
17096144 Throttle body (1998 L29 7.4L)
12570168 Throttle body gasket
1000LS1U Throttle cable
20416 Upper rad hose (Gates)
When swapping one of these engines in to a pre-GMT400 truck, the ORD HD engine crossmember works perfectly to address oil pan clearance. Taking a torch to the stock crossmember is just hacky…buy a nice ORD piece.

Swap info:

- The L18 8.1L has the same foot print as older BBC engines and will bolt in the same as any other older SBC and BBC. In fact, the L18 will accept any exhaust manifold or header from older BBC engines. The starter motor from any older SBC and BBC for use with a 168 tooth flywheel will also fit the L18. Any transmission from an old PowerGlide, TH350, TH400 to Allison, to NV4500, etc. will bolt on to it as well.
It is not required to run electronic throttle control on these engines. If you choose to keep it simple and reliable like I did, you can use a 1996-2000 L29 7.4L cable operated throttle body on the 8.1L. Cruise control could be adapted to mechanical TB buy using the cruise control controller from a L29 as well. An aftermarket TB spacer is required to be able to use the L29 TB in order to allow room for the arm to swing.

- These engines love higher than spec fuel pressure. Crank it up to about 67-68 psi and watch it come alive! (The adjustable fuel pressure regulator makes the early 2001-2003 fuel rails more desirable).

- There are 4 different accessory bracket designs used on these engines. In my experience, the G-van/Workhorse/GM Medium Duty accessory brackets are ideal for swapping into a vehicle with A/C as the A/C compressor is located up high on the driver’s side whereas the Silverado/Sierra brackets position the A/C compressor down low on the passenger’s side which causes a major frame clearance issue during swapping. To convert a pickup truck L18 to the the high mount compressor design the water pump, crank pulley/balancer must be replaced as well. Don’t be that guy to hack up a frame to make room for the A/C compressor! If not running A/C, the Silverado/Sierra brackets will work fine. More information on that below.

Wiring: Like any late model engine swap, there are many different avenues for wring these engines. I personally do not like going the route of reworked donor truck harnesses. There is just too much that needs to be removed from a donor harness to bring it down to a manageable/clean size and the margin of error while rewiring it is just too great. In my opinion the only way to go is start with a fresh stand- alone harness from Howell Engine Development or one of the many other good harness suppliers out there.

Identification Photo’s:

This is the most commonly found accessory bracket design, as it is the Silverado/Sierra setup. The location of the A/C compressor causes frame interference when swapping into an older truck. If installing into a non-A/C vehicle these brackets are great. Just remove this compressor and eliminate the belt.

http://www.lt1swap.com/vortec8100.htm

http://mcspeed.homestead.com/Killer-II.html

http://www.raylarengineering.com/vortec ... parts.html

http://www.digitalcorvettes.com/forums/ ... p?t=148376

http://www.dartheads.com/products/cylin ... -head.html
bbcgen7head_2.jpg


http://archives.media.gm.com/us/powertr ... 0Block.pdf

The 2001 truck line includes a new 8.1 liter 496 cubic inch "8100" big block. The bore will remain at 4.250", but the stroke will be increased to 4.370". The firing order is also new 1-8-7-2-6-5-4-3 and features individual ignition coils mounted near the spark plugs, similar to the LS1 Gen. III smallblocks. CR is 9.1-1 and it uses Sequential Fuel Injection (SFI). All 8.1 liter BBC production motors come with an internally balanced crank, four bolt main caps and redesigned heads with equal length port runners. The 2001 model 8.1 liter BBC uses a roller hydraulic cam and makes 340HP @ 4200 rpm and 455 ft./lbs. @ 3200 rpm. You'll be able to get either an Allison 1000 5-speed auto trannie or a new ZF S6-650 six speed manual gearbox with this new big block. Both trannies are built for a maximum of 520 ft./lbs. of torque.

The Marine versions of the 8.1 liter big block comes in two power levels, a 375hp/490 ft./lb. model or a 415hp/490 ft./lb model.
8100

The Vortec 8100 (RPO L18) is a V8 truck engine. It is a redesigned Chevrolet Big-Block engine and was introduced with the 2001 full-size pickup trucks. It retains the same bore centers as the old 7.4 L big-blocks, but stroke was upped by 9.4 mm to reach 8.1L (496cuin) for a total of 107.95 mm bore and 111 mm stroke. It is an all-iron engine (block and heads) with two valves per cylinder. Power output ranges from 225 hp (168 kW) to 340 horsepower (250 kW) and torque from 350 lb·ft (475 N·m) to 455 lb·ft (617 N·m). Vortec 8100s are built in Tonawanda, New York. The Vortec 8100 is the engine used in the largest Uhaul, their 26-foot (7.9 m) truck. GM stopped installing big block V-8's in the Silverado HD trucks, when the GMT-800 series was discontinued in 2007


http://www.sae.org/automag/techbriefs_05-00/11.htm

http://www.raylarengine.com/index.html


http://powerandmotoryacht.com/engines/0101vortec/
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2005 Model Year Summary

· New for Chevrolet Kodiak and GMC TopKick with four-wheel drive
· Floating pin pistons
· Returnless fuel injection for marine applications
· Improved oil pan (for medium duty applications)
· Improved throttle actuator control module
· Rate-based diagnostics
· GF-4 engine oil

FULL DESCRIPTIONS OF NEW OR CHANGED FEATURES

NEW FOR CHEVROLET KODIAK AND GMC TOPKICK WITH FOUR-WHEEL DRIVE
For 2005, the Vortec 8100 will be available in Chevrolet Kodiak and GMC Topkick medium-duty trucks with four-wheel drive. Vortec 8100s built for this application require packaging adjustments to accommodate a front transaxle, including exhaust manifolds, heat shields and starter motor.

FLOATING PIN PISTONS
The Vortec 8100 is fitted with new floating-pin pistons. Introduced previously on GM Powertrain’s Vortec 6000 V-8, these pistons feature wrist pins that “float” inside the rod bushing and the pin bores in the piston barrel. Previously, the Vortec 8100 used a fixed-pin assembly, in which the connecting rod is fixed to the piston’s wrist pin, and the pin rotates in the pin bore. In the Vortec 8100, snap rings now retain the wrist pin in the piston, while the rod moves laterally on a bushing around the pin.

The Vortec 8100’s pistons, piston rings and connecting rods are identical to those used in 2004. The new floating-pin assembly allows tighter pin to pin-bore tolerances and reduces noise generated during engine operation.

RETURNLESS FUEL INJECTION FOR MARINE APPLICATIONS
All Vortec 8100s built for marine application are equipped with a new ``returnless’’ fuel injection system that eliminates fuel return lines between the engine and the gasoline tank. The new fuel system is also known as a demand system, and was introduced on Vortec 8100s built for the Chevrolet Silverado and GMC Sierra for model year 2004.

Before model year 2004, the sequential fuel injection (SFI) on all Vortec 8100s used a return line to manage fuel pressure by bleeding off excess fuel at the fuel rail and returning the excess to the tank. The new system eliminates the return lines and moves the fuel pressure regulator from the fuel rail on the engine to the fuel tank. The fuel line from the tank now includes pulse dampeners, or a series of baffles, that manage fuel pulsing and limit noise.

Because it delivers only the amount of fuel need by the injectors, and returns no fuel to the gas tank, the returnless system essentially eliminates heat transfer from the engine to tank. This reduces the amount of vapor generated in the tank and released as evaporation. The returnless system has been introduced on marine engines to give marine customers the same emissions standards and efficient operation as truck customers.

IMPROVED OIL PAN FOR MEDIUM DUTY AND MARINE APPLICATIONS
The oil pan on Vortec 8100s built for medium-duty (C4-C8 trucks) and marine use has been redesigned. This cast aluminum oil pan is essentially identical for both applications, with differences limited to final machining.

With the new pan, the interior baffle has been reconfigured to maximize oil flow, improve durability and stiffen the cast-aluminum pan’s structure, further reducing engine vibration. Moreover, sump capacity for medium-duty trucks increases 3.1 liters. The change was driven by the demands of the commercial fleet and rental markets. Rental truck customers may not be the most diligent operators when it comes to monitoring oil levels. The larger sump adds an extra measure of security for rental companies and fleet operators, even if customers use trucks for weeks without checking oil levels.

IMPROVED THROTTLE ACTUATOR CONTROL MODULE
All Vortec 8100’s are equipped with an improved throttle actuator control (TAC) module. Located on the throttle body, the TAC module is an integral component of the Vortec 8100’s electronic throttle control (ETC) system. The TAC takes command from the powertrain control module (PCM) and then operates the motor that opens and closes the throttle plate.

The TAC module has new read-only memory and control software. Like its predecessor, it allows multiple throttle progressions or algorithms, which operate the throttle at varying rates according to operating conditions and driver demands. It also has built-in default settings that protect the engine and ensure safe operation in the event of malfunction with the ETC or other engine subsystems.

RATE-BASED DIAGNOSTICS
The Vortec 8100’s powertrain control module (PCM) uses a new monitoring protocol known as rate-based diagnostics. Rate-based diagnostics improve the robustness of the Onboard Diagnostics System (OBD II) and ensure optimal performance of emissions control systems.

With rate-based diagnostics, the PCM applies a new formula to manage OBD II. Essentially, new software increases the frequency at which the PCM checks various engine systems, and particularly emissions-control systems such as the catalytic converter, oxygen sensors and exhaust gas recirculation (EGR). Rate-based diagnostics more reliably monitor real-word operation of these systems, and allow regulatory agencies to more easily measure and certify emissions compliance. The new protocol allows the Vortec 8100 to meet more stringent OBD II requirements two years ahead of a mandate by the California Air Resources Board.

GF-4 ENGINE OIL
All Vortec 8100s will be shipped to customers with a new engine oil that reduces engine deposits, extends oil change intervals, improves fuel economy and extends the life of emissions control systems. GM Powertrain has taken a leading role in developing and introducing the new oil, designated GF-4 (for “Gasoline Fueled, Standard 4’’) by the American Petroleum Institute.

GF-4 contains a new ash-free antioxidant ingredient and less phosphorous than the previous formulation (GF-3). The typical automotive engine now operates at a much higher temperature than an engine built 10 years ago. GF-4 is twice as resistant to oxidizing, which can present itself as foaming, at high operating temperatures. At the same time, GF-4 provides better low-temperature protection, reducing engine wear during the critical cold-start period. Lower phosphorus and sulfur content – chemicals that are harmful to catalytic converters – will extend anticipated catalyst life beyond 120,000 miles. Finally, GF-4 lowers friction overall and retains its optimal friction-reducing characteristics longer. The result is an anticipated improvement of 0.2 percent to 0.3 percent in an engine’s fuel economy, and longer oil change intervals.

Production of Vortec 8100s with GF-4 begin in fall 2004, ahead of an industry recommendation of April 30, 2005. This will allow vehicles with the Vortec 8100 to be tested for 2005 Corporate Average Fuel Economy (CAFE) standards with GF-4. GM’s industry-leading Oil Life System may be adjusted to account for the new oil. The owner’s manual in vehicles equipped with the Vortec 8100 will continue to recommend oil with the Starburst logo, which must be certified to GF-4 by May 2005.

OVERVIEW

Few words generate excitement for car and truck enthusiasts like ‘’Big Block.’’ The Vortec 8100 V-8 is the legendary GM Big Block for a new millennium, with a longer expected useful life and horsepower and torque that surpass the large displacement gasoline engines offered in competitors’ heavy-duty pickups. This heavy-duty engine also sets benchmarks for marine and industrial application worldwide.

Introduced in the 2001 Chevrolet Silverado and Suburban and GMC Sierra and Yukon XL, the Vortec 8100 was essentially a new engine. Nearly 90 percent of its parts have been completely redesigned. While it shares its valve centers, bore centers and bore diameter with the previous 7.4L Big Block, stroke was increased 9.4 mm (.37 inch) to increase displacement 700 cc. The latest math-based engineering tools were used to improve the flow and distribution of oil and coolant, to refine castings and to improve production quality and efficiency.

After extensive analysis of competitors' engines, the Vortec 8100 development team set a goal of 200,000 miles of useful life without major repairs – and then achieved it. Before it was ready for production, this big block had to pass the “Marine Dock'' test, in which it is run at full throttle for 300 consecutive hours without a failure, and a minimum of 1,000 hours at full-throttle operation for truck applications.

In the four years since its launch, virtually every aspect of the engine – from sealing to electronic management to noise, vibration and harshness control – has been re-examined and improved. For 2004, Vortec 8100s built for truck installation were equipped with a new returnless fuel injection system that eliminated fuel return lines between the engine and the gasoline tank and reduced evaporative emissions. Combined with new intake manifold and throttle body gaskets, manufactured of an advanced fluorocarbon material that is virtually impermeable to hydrocarbon molecules, the returnless fuel system allows the Vortec 8100 to meet near-zero evaporative emissions standards. Also in 2004, Vortec 8100s built for industrial applications were equipped with new valves, valve seat material and springs designed expressly for industrial operation at low, steady rpm.

GM's leadership in big-block V-8 technology dates to at least 1958, when the Vortec 8100's progenitor was launched with 348 cubic inches of displacement in the full-size 1958 Chevrolets. The 348 was followed by several variants, including a 409, 366 and 427. In 1970, the 454-cubic-inch big-block was introduced. It was retooled in 1991 as the Vortec 7400 – a truly powerful pickup engine that met stringent 1990s emission requirements. The Vortec 8100 bears little resemblance to those engines, but it maintains a tradition of outstanding durability and class-leading power.
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grumpyvette

Administrator
Staff member
yeah! read thru the linked info its well worth the effort required

http://www.raylarengineering.com/vortec ... parts.html

https://www.youtube.com/watch?v=GYFOyMiSfYM

https://www.youtube.com/watch?v=mDcQ9DM3SOU

http://mcspeed.homestead.com/Not-Anothe ... -Swap.html

http://mcspeed.homestead.com/Not-Anothe ... rt-II.html


there are performance parts available now that were not until recently


http://lt1swap.com/vortec8100.htm

http://www.raylarengineering.com/

http://www.performancetrucks.net/forums ... es-517282/

http://coloradok5.com/forums/showthread.php?t=308019





FULL DESCRIPTIONS OF NEW OR CHANGED FEATURES

APPLICATION IN CHEVROLET KODIAK AND GMC TOPKICK
The Vortec 8100 8.1L V8 (L18) is now offered in the Kodiak and TopKick, or commercial duty Family II and Family III trucks. These chassis-cabs provide the foundation for a host of vehicles from delivery vans to small dump trucks. The Vortec 8100 will be available with three gross vehicle weight ratings (GVWR): 16,000, 18,000 and 19,500 lbs. The Kodiak and TopKick replace 3500 HD and medium-duty chassis cabs. The 8.1L was launched in Kodiaks and TopKicks built from early calendar 2002 as 2003 models.

Depending on how the vehicle is ultimately finished, Family II and Family III trucks can generate far greater electrical demands than the typical truck. For these applications, the 8.1L can be equipped with two 105-amp alternators rather than a single 140-amp alternator (the second alternator is mounted on the right side of the engine). The accessory drive belt is therefore longer in these applications.

CHEVROLET EXPRESS AND GMC SAVANA APPLICATION ELIMINATED
The Vortec 8100 is no longer an option in the Express and Savana. The Vortec 6000 6.0L (LQ4) will be the most powerful engine offered in the redesigned 2003 models (see Product Specifications).

POWERTRAIN CONTROL MODULE AND SOFTWARE WITH ADDITIONAL MONITORING FUNCTIONS
A new Powertrain Control Module (PCM), called P59, manages the 8.1L. With this new PCM, processor clock speed increases from 21 to 24 mHz and memory capacity doubles to 1.1 megabytes. The PCM also manages the 4.3L V6 (LU3) and all gasoline-powered Vortec V8 truck engines, and provides one of the most sophisticated engine control systems in the industry.

Commonality offers the advantage of reducing inventory complexity and increasing efficiency at various assembly plants. More important, P59 offers the most precise engine management possible, optimizing performance according to temperature or operating conditions and virtually eliminating unintended variation in every function it controls, from ignition timing to fuel delivery to transmission shift points. It also allows GM Powertrain engineers to monitor more engine operations and improves the accuracy and robustness of the OBDII (On-Board Diagnostics) system.

For example, the PCM now measures electrical current flowing to the oxygen or 02 sensors (crucial components of the emissions-control system) on vehicles equipped with the Vortec 8100. Previously, the O2 sensors were monitored with a time-to-activity algorithm, which required more measurement latitude to ensure proper operation. The new PCM more quickly reports a malfunction in an O2 sensor with virtually no margin for misreporting. It also allows a new Engine Off Natural Vacuum (EONV) diagnostic for the Onboard Refueling Vapor Recovery system (ORVR), which reduces evaporative emissions by preventing gasoline vapor from escaping the vehicle into the atmosphere. With EONV, the PCM continues to operate when the engine is turned off, monitoring pressure in the fuel tank and ORVR system. If pressure bleeds off more quickly than ambient temperature and other conditions indicate, the PCM can determine whether the system has a leak, even when the vehicle is parked. The new PCM ensures that the engine operates according government emissions regulations. And thanks to its precision, it will also reduce the number of false alarms— OBDII “service engine” warning lights—that require dealer intervention.

The new PCM is roughly the same size as the PCM it replaces and is installed in the same place as the previous PCM in various applications—in all applications on the firewall or inner fender, depending on the vehicle. There is no visible difference in the engine bay.

IMPROVED DENSO OXYGEN (O2) SENSORS
The Vortec 8100 has new oxygen (O2) sensors. These O2 sensors have the same 6.6-volt heat rating as the parts they replace, allowing them to achieve closed loop operation—and maximum exhaust emissions reduction--in minimum time. The new sensors allowed engineers to implement the current monitoring function provided by the new PCM, and they are common to other truck gasoline V8s.

SOLID STATE OIL-PRESSURE SENSOR
The 8.1L now has a fully electronic, solid-state oil pressure sensor, replacing an analog/mechanical sensor. The solid-state sensor is installed in the same location in the engine block, but it has no mechanical parts, increasing reliability. Its introduction coincides with a new electronic instrument package in some applications.

REVISED ELECTRONIC THROTTLE BODY
The Electronic Throttle Control (ETC) system on the 8.1L uses a new throttle body and Throttle Actuator Control (TAC) module. The throttle body’s diameter (75 millimeter) has not changed, but the new part features a ``wrap around’’ throttle motor. The electric motor that operates the throttle plate is literally built around the throttle body and responds more quickly to commands from the TAC. The new throttle body is now common to all gasoline-powered GM truck V8s.

Before the Vortec 8100, ETC was largely reserved for premium passenger car engines and some heavy duty trucks. There is no mechanical link between the accelerator pedal and the throttle. Besides throttle pedal angle, the PCM measures other data, including the transmission's shift points, in determining how far to open the throttle. ETC delivers outstanding throttle response and can be calibrated to match demands in different applications.

COOLANT FLOW FROM HEATER CORE REVISED ON SILVERADO AND SIERRA
In the 8.1L applications, the flow pattern for engine coolant has been revised to heat the cab more quickly during cold temperature operation.

The heater core is a small radiator inside the vehicle’s instrument panel, behind the engine firewall. Hot coolant from the engine flows through the heater core, where the ventilation fan forces heat through ductwork to the dash vents and into the cab. In extremely cold temperatures, large displacement engines such as the 8.1L can take some time to reach a temperature sufficient to heat the cab. GM engineers have developed a simple, effective method to increase customer comfort by shortening the time it takes to heat the cab.

On Silverados and Sierras, the heater return hose is now routed into the radiator return hose rather than the radiator itself. That means the coolant flowing in and out of the heater core bypasses the radiator, where coolant is at its coldest temperature anywhere in the cooling system. Coolant flowing to the heater core stays out of the radiator until the engine reaches full operating temperature and the thermostat opens. This allows the cab to heat more quickly, meeting GM’s stringent time standard, without reducing cooling capacity during high-temperature operation.


CATALYTIC CONVERTER REVISED
The mix of precious metals in the 8.1L catalytic converter has been revised for all applications to meet more stringent 2003 exhaust emissions standards. The new converter has the same volume as the one it replaces, with similar architecture. The difference lies in the combination of platinum, palladium, rhodium and other rare metals in the converter substrate, or core. These metals create the chemical reaction that turns the majority of exhaust emissions into oxygen and water vapor. The combination has been optimized to achieve emission standards with more of the common varieties of these metals and less of the rarest types. This process limits environmental impact and keeps cost to the customer as low as possible.

REVISED OIL FILL TUBE AND CAP
The oil fill tube on 8.1Ls built for Silverado and Sierra has been revised to accommodate the new throttle body. The tube is angled more sharply as it rises from the engine block. It is also manufactured from molded plastic rather than steel, and sealed with an O-ring rather then a press-fit seal (the fill tube on L18s built for Workhorse Custom Chassis is still made of steel). Finally, the fill tube on all 8.1Ls except those built for the Chevrolet Kodiak and GMC TopKick, have a new corporate cap with a global symbol rather than the word ``oil.’’

REVISED OIL LEVEL INDICATOR
The word “Oil” stamped on the dipstick has been removed to comply with global labeling laws.

SIGHT SHIELD REVISED FOR CHEVROLET SILVERADO, SUBURABAN AND AVALANCHE AND GMC SIERRA AND YUKON XL
The thermoplastic sight shield or ``Vortec 8100 cover’’ around the 8.1L intake manifold and fuel rail has been revised to fit over the new throttle body. The sight shield dampens mechanical noise from the engine and gives the Vortec 8100 its up-to-date, finished look.

STARTER FOR SILVERADO, SUBURABAN, AVALANCHE, SIERRA AND YUKON XL
8.1Ls built for these applications are equipped with a different starter than other applications. Specifications are virtually identical, but this starter motor requires no heat shield and offers mass and packaging advantages. These applications now require a smaller heat shield for the knock sensor.

EXHAUST VALVES REVISED ON MARINE VARIANT
Exhaust valves on 8.1Ls built for marine applications are no longer treated with a Stellite surface hardener. There is no functional change for the customer. The Stellite-faced valves for marine use date to the leaded-fuel variant of the engine. Production of leaded-fuel 8.1Ls ended after the 2001 model year. All export engines are now built to U.S federal emission standards, which ensures that all Vortec 8100s produce the fewest exhaust emissions possible and allows GM Powertrain to focus further development on a common engine.

OVERVIEW
Introduced in the 2001 Chevrolet Silverado and Suburban and GMC Sierra and Yukon XL, the 8.1L is the legendary GM Big Block for a new millennium, with a longer expected useful life and horsepower and torque that surpass the competition. GM's leadership in big-block V8 technology dates to 1958, when the Vortec 8100's progenitor was launched with 348 cubic inches of displacement, in the full-size 1958 Chevrolets. The 348 was followed by several variants, including a 409, 366 and 427. In 1970, the 454-cubic-inch big-block was introduced. It was retooled in 1991 as the Vortec 7400--a truly powerful pickup engine that met stringent 1990s emission requirements. The Vortec 8100 bears little resemblance to those engines, beyond its bore centers and bore diameters, but it maintains a tradition of outstanding durability and class-leading power. Based on published figures in January 2002, the engine delivers more horsepower and torque than any gasoline engine in the heavy-duty pickup market.

After extensive analysis of competitors' engines, the 8.1L development team set a goal of 200,000 miles of useful life without major repairs--and then achieved it. The engine has been tested and validated to meet this 200,000-mile durability standard. Before it was ready for production, the 8.1L had to pass the ``Marine Dock'' test, in which it is run at full throttle for 300 consecutive hours, and a minimum of 1000 hours at full-throttle operation for truck applications. .

Durability is only one component of success in the heavy-duty pickup market. Another is outstanding power, and measured by both horsepower and torque, the Vortec 8100 beats its V10 competition.
 

grumpyvette

Administrator
Staff member
larry said:
I am active on 3 main forums (67-72chevytrucks, Expedition Portal, and CK5) and on average I get 3 to 5 PM’s and emails each week related to 8.1L swap questions from people all over world into every imaginable vehicle. While it is fun to answer each and every PM, it eats up a lot of time. Since don’t have time to write a book and make a profit on it I am hoping to make this thread the main resource thread to steer people to in the future .

The following information is a cumulation of information from GM Powertrain Application Manuals, Technical Data Sheets and GM Service Manuals

L18 8.1L vehicle applications:

2000-2011 Workhorse Custom Chassis
Transmissions: 4L80E, Allison 1000, Allison 2200

2001-2002 GMT400 3500-HD trucks (these were the 1988-2000 body style chassis cab trucks with leaf sprung I-beam front axles. All left GM as 2wd but many were converted to 4x4 in the aftermarket).
Transmission options: NV4500 & 4L80E

2001 – 2002 Chevrolet Express/GMC Savanna (G-Van)
Transmission option: 4L80E

2001-2006 GMT800 2500HD/3500 (& 2007 GMT800 Classic)
Transmission option: Allison 1000, ZF S6-650 6 speed manual

2001-2006 Suburban/Yukon XL/Avalanche 2500
Transmission option: 4L80E

2001-2009 GM Medium Duty trucks
Transmission option: Allison 1000, Allison 2200, ZF S6-650 6 speed manual, Eaton 5 speed manual

GM Powertrain also sold the L18’s to various Marine engine manufacturers where they marketed it under their own names. The two main users were VolvoPenta and Mercruiser. Both had a few different versions of the L18 with different HP ratings.

L18 HP and torque ranges depending application: 340HP/455 LB. FT to 420HP/505 LB. FT (Marine)

L18 GVWR Ranges: 8,600 lbs. to 44,000 lbs (Medium Duty & RV)

The 8.1L is still in production but not by GM Powertrain. PSI is building the 8.1L and an 8.8L version under license for other truck manufacturers like Freightliner, International, as well as industrial well pumps and generators.

Notable items:

- The L18 8.1L is 496 cubic inches, not 502. The marketing name was Vortec 8100, not Vortex.

- 2001-2003 L18’s use a return type fuel system. This means there are two fuel lines at the fuel rail. One supply and one return. There is an adjustable fuel pressure regulator on the fuel rail return side.

- 2004-2010 L18’s use a returnless fuel system. The purpose of moving to a returnless system was done for the purpose of reducing evaporative emissions by eliminating hot fuel being returned to the fuel tank. The fuel pressure regulator looking thing on the fuel rail is actually a fuel damper. Fuel pressure is regulated by a non-adjustable regulator in the fuel module assembly located in the fuel tank. 2004 also brought a new design intake gasket set and change in intake bolt lengths to address oil and coolant consumption.

- 2003 brought a new design throttle body with a much smaller motor. This seemed to help address the touchy throttle on previous years.

- 2003 also brought new bare aluminum valve covers

- 2004 brought new designs with the Cam and Crank sensors to improve durability. The later designs work great! Prior sensors, especially the crank sensor, are extremely prone to premature failure.

- EGR was also eliminated with the 2004 model year

- In the GMT800 truck application, the L18 makes 355 LB. FT. of torque at 800 RPM with a peak torque of 455 LB. FT. at 3,200 RPM. That is over 300 LB. FT. of torque at idle! Not many stock gasoline engines can claim that much twist at idle.

- The L18 is one of the only engines to pass the ``Marine Dock'' test, in which it is run at full throttle for 300 consecutive hours, and a minimum of 1000 hours at full-throttle operation for truck applications. Not many engines carry this accolade. The Ford V10 has not passed this test.

- All L18 engines from 2000 to 2011 ran on the Delphi P59 ECM, while the later small block LS engines moved onto E38 and E78 modules.

GM Service Bulletins related to L18 engines:

#01-06-01-018: Engine Tick Noise at Valve Train Speed/Loss of Power (Replace Push Rod) - (Jun 29, 2001)

#02-06-01-015: Info - Low Oil Pressure and New Oil Level
Indicator - (Apr 17, 2002)

#02-06-01-035: High Oil Consumption (Replace Intake Manifold Bolts) - (Oct 17, 2002)

#04-06-01-018: Information on Revised Design of Intake Gasket and Related Bolts for 2004 Mid Year Enhancement and Prior Year Service Usage - (Jun 3, 2004)

#06083: Product Safety - Crankshaft Position Sensor Engine Stall - (Dec 11, 2007)


Engine Mechanical Specifications Application
Specification

Metric
English

General

Engine Type

V8

Displacement

8.1L
496 CID

RPO

L18

VIN – Light Duty

G

VIN – Medium Duty

E

Bore

107.95 mm
4.25 in

Stroke

111.0 mm
4.37 in

Compression Ratio

9.1:1

Firing Order

1-8-7-2-6-5-4-3



Part Numbers used for my swap: Keep in mind, my part numbers are for use with a manual transmission, mechanical throttle body and return type fuel system along with the G-van/Workhorse/Medium duty accessory brackets.

Part Number Description
52445253 A/C compressor
11516360 A/C compressor bolts
12581203 Belt tensioner
11516367 Belt tensioner bolt
12578330 Coolant Crossover
12571593 Coolant Crossover gasket
12575172 Crank Sensor
12575123 Dipstick
12570590 Dipstick tube
12559976 EGR Cover
12580673 EGR Cover gasket
12574560 Engine Cover
12567370 Engine Cover Ball Stud
12562957 Engine Cover Bracket
12562958 Engine Cover Bracket Stud
12582964 Flywheel
12563485 Flywheel bolts
EP381 Fuel pump
W0000393 HOUSING ASM - PCM
12580771 Idler on alternator bracket
213-298 Knock sensor - Drivers side
213-2829 Knock sensor - Passenger
12573337 Oil Cap
12573337 Oil Cap
12581140 Oil Fill Tube
11518950 Oil fill tube stud
12568356 Oil pump drive
12575055 RAIL KIT,M/PORT F/INJN FUEL
17096144 Throttle body (1998 L29 7.4L)
12570168 Throttle body gasket
1000LS1U Throttle cable
20416 Upper rad hose (Gates)
When swapping one of these engines in to a pre-GMT400 truck, the ORD HD engine crossmember works perfectly to address oil pan clearance. Taking a torch to the stock crossmember is just hacky…buy a nice ORD piece.

Swap info:

- The L18 8.1L has the same foot print as older BBC engines and will bolt in the same as any other older SBC and BBC. In fact, the L18 will accept any exhaust manifold or header from older BBC engines. The starter motor from any older SBC and BBC for use with a 168 tooth flywheel will also fit the L18. Any transmission from an old PowerGlide, TH350, TH400 to Allison, to NV4500, etc. will bolt on to it as well.

- It is not required to run electronic throttle control on these engines. If you choose to keep it simple and reliable like I did, you can use a 1996-2000 L29 7.4L cable operated throttle body on the 8.1L. Cruise control could be adapted to mechanical TB buy using the cruise control controller from a L29 as well. An aftermarket TB spacer is required to be able to use the L29 TB in order to allow room for the arm to swing.

- These engines love higher than spec fuel pressure. Crank it up to about 67-68 psi and watch it come alive! (The adjustable fuel pressure regulator makes the early 2001-2003 fuel rails more desirable).

- There are 4 different accessory bracket designs used on these engines. In my experience, the G-van/Workhorse/GM Medium Duty accessory brackets are ideal for swapping into a vehicle with A/C as the A/C compressor is located up high on the driver’s side whereas the Silverado/Sierra brackets position the A/C compressor down low on the passenger’s side which causes a major frame clearance issue during swapping. To convert a pickup truck L18 to the the high mount compressor design the water pump, crank pulley/balancer must be replaced as well. Don’t be that guy to hack up a frame to make room for the A/C compressor! If not running A/C, the Silverado/Sierra brackets will work fine. More information on that below.

Wiring: Like any late model engine swap, there are many different avenues for wring these engines. I personally do not like going the route of reworked donor truck harnesses. There is just too much that needs to be removed from a donor harness to bring it down to a manageable/clean size and the margin of error while rewiring it is just too great. In my opinion the only way to go is start with a fresh stand- alone harness from Howell Engine Development or one of the many other good harness suppliers out there.

Identification Photo’s:

This is the most commonly found accessory bracket design, as it is the Silverado/Sierra setup. The location of the A/C compressor causes frame interference when swapping into an older truck. If installing into a non-A/C vehicle these brackets are great. Just remove this compressor and eliminate the belt.
8100p1.jpg

This setup moves the compressor to high towards the driver's side like older engines. This setup is found on G-van's, Workhorse and GM Medium duty. The power steering pump in this picture is a ZF, not the typical Saginaw type pump although a Saginaw pump will fit this type bracket. If you would like to order any of the pieces for this set up use VIN 3GBKC34G61M101958 for part number look up.
8100p2.jpg
 

grumpyvette

Administrator
Staff member
2006 model year summary

• Increase to 325 horsepower for Chevrolet Suburban, Avalanche and GMC Yukon XL
• New dual mid-coupled converter system
• Returnless fuel injection for Chevrolet Kodiak and GMC TopKick
• Improved electronic throttle control pedal and throttle actuator control (TAC) module
• Recalibrated P59 engine controller

Full descriptions of new or changes features
Increase to 325 horsepower For the 2006 Chevrolet Suburban, Avalanche and GMC Yukon XL 2500 Series, the Vortec 8100 delivers an additional 5 horsepower. Increased power results from reduced backpressure in the exhaust system, enabled by a new catalytic converter system. The new converter system is primarily designed to lower emissions. The Vortec 8100’s new rating is 325 horsepower and 447 lb.-ft. of torque.

New dual mid-coupled catalytic converter system Chevrolet Suburban, Avalanche and GMC Yukon XL three-quarter-ton models equipped with the Vortec 8100 receive a new M120 mid-coupled catalytic converter system. Two new mid-coupled converters replace four previous ones (two mid-coupled and two under-floor converters). The new dual converters, with about two liters of volume, are also located closer to the exhaust manifold to enhance their effectiveness. Their construction, consisting of multiple materials, is unchanged. While providing lower LEV emissions levels, the new converter system also allows a more moderate 47.1 kPa of exhaust back pressure for more power. Induction restriction is unchanged.

Improved electronic throttle control and throttle actuator control module
With the Vortec 8100, the Chevrolet Suburban, Avalanche and GMC Yukon XL 2500 Series also receive an improved electronic throttle control pedal and improved throttle actuator control (TAC) module. The throttle pedal provides more consistent truck-to-truck pedal force and effort feel for vehicle operators. The TAC is designed to accommodate the new pedal. Located on the engine side of the front of dash, the TAC module is an integral component of the Vortec 8100’s electronic throttle control (ETC) system. The TAC takes command from the powertrain control module (PCM) and then operates the motor that opens and closes the throttle plate. Like its predecessor, the TAC module has read-only memory and control software. It allows multiple throttle progressions or algorithms, which operate the throttle at varying rates according to operating conditions and driver demands. It also has built-in default settings that protect the engine and ensure safe operation in the event of malfunction with the ETC or other engine subsystems.
Returnless fuel injection for Chevrolet Kodiak and GMC TopKick
For 2006, the Vortec 8100 available in Chevrolet Kodiak and GMC Topkick medium duty trucks is equipped with a new "returnless" fuel injection system that eliminates fuel return lines between the engine and the gasoline tank. The new fuel system is also known as a demand system. The system is already used with the Vortec 8100 on Chevrolet Silverado and GMC Sierra models and with all Vortec 8100s built for marine applications.

Before 2006, the Sequential Fuel Injection (SFI) in medium duty trucks equipped with the Vortec 8100 used a return line to manage fuel pressure by bleeding off excess fuel at the fuel rail and returning the excess to the fuel tank. The new system eliminates the return lines and moves the fuel-pressure regulator from the fuel rail on the engine to the fuel tank. But because the returnless system delivers only the amount of fuel needed by the injectors, and returns no fuel to the fuel tank, it eliminates heat transfer from the engine to the fuel tank. This reduces the amount of vapor generated in the tank and captured by the evaporative emissions control system. Recalibrated P59 engine controller.

The Vortec 8100’s P59 engine controller in medium duty trucks is recalibrated to coordinate with the newly available version of the Allison five-speed automatic transmission and the returnless fuel injection system. The P59 also has new calibrations to optimize driveability and fuel economy with the new Allison six-speed automatic transmission being introduced for the first time in GM full-size pickups.

Overview
Few words generate excitement for car and truck enthusiasts like ‘’Big Block.’’ The Vortec 8100 V-8 is the legendary GM Big Block for a new millennium, with a longer expected useful life and horsepower and torque that surpass the large-displacement gasoline engines offered in competitors’ heavy-duty pickups. This heavy-duty engine also sets benchmarks for marine and industrial application worldwide.

Introduced in the 2001 Chevrolet Silverado and Suburban and GMC Sierra and Yukon XL, the Vortec 8100 was essentially a new engine. Nearly 90 percent of its parts have been completely redesigned. While it shares its valve centers, bore centers and bore diameter with the previous 7.4L big block, stroke was increased 9.4 mm (.37 inch) to increase displacement 700 cc. The latest math-based engineering tools were used to improve the flow and distribution of oil and coolant, to refine castings and to improve production quality and efficiency.

After extensive analysis of competitors' engines, the Vortec 8100 development team set a goal of 200,000 miles of useful life without major repairs – and achieved it. Before it was ready for production, this big block had to pass the “Marine Dock'' test, in which it is run at full throttle for 300 consecutive hours without a failure, and a minimum of 1,000 hours at full-throttle operation for truck applications.
In the five years since its launch, virtually every aspect of the engine – from sealing to electronic management to noise, vibration and harshness control – has been re-examined and improved.

For 2005, the Vortec 8100 was made available in Chevrolet Kodiak and GMC TopKick trucks with four-wheel drive. GM’s big block was fitted with floating-pin piston rings, which allow tighter pin to pin-bore tolerances for quieter operation and increased durability. Returnless fuel injection was incorporated in all marine applications. Medium duty trucks received an improved oil pan. All Vortec 8100s received an improved throttle actuator control. Their powertrain control module began using a monitoring protocol, known as rate-based diagnostics, to increase the robustness of the Onboard Diagnostics System and optimize performance of the emissions control systems. All Vortec 8100s
began being shipped with GF-4 engine oil that reduces engine deposits, extends oil change intervals, improves fuel economy and extends the life of emissions control systems.

For 2004, Vortec 8100s built for Chevrolet Silverado and GMC Sierra pickups were equipped with a new returnless fuel injection system that eliminates fuel return lines between the engine and the gasoline tank and reduces evaporative emissions. Combined with new intake manifold and throttle body gaskets, manufactured of an advanced fluorocarbon material that is virtually impermeable to hydrocarbon molecules, the returnless fuel system allows the Vortec 8100 to meet near-zero evaporative emissions standards. Also in 2004, Vortec 8100s built for industrial applications were equipped with new valves, valve seat material and springs designed expressly for industrial operation at low, steady rpm.

GM's leadership in big block V-8 technology dates to at least 1958, when the Vortec 8100's progenitor was launched with 348 cubic inches of displacement in the full-size 1958 Chevrolets. The 348 was followed by several variants, including a 409, 366 and 427. In 1970, the 454-cubic-inch big-block was introduced. It was retooled in 1991 as the Vortec 7400 – a truly powerful pickup engine that met stringent 1990s emission requirements. The Vortec 8100 bears little resemblance to those engines, but it maintains a tradition of outstanding durability and class-leading power
__________________

2007 model year summary

• Hexavalent Chrome Eliminated

Full descriptions of new or changes features

HEXAVALENT CHROME ELIMINATED
An ongoing process to eliminate heavy metals from engines results in one small component—the drain plug—being replaced by a hexavalent chrome-free part.

Overview
Few words generate excitement for car and truck enthusiasts like ‘’Big Block.’’ The Vortec 8.1L V8 is the legendary GM Big Block for a new millennium, with a longer expected useful life and horsepower and torque that surpass the large-displacement gasoline engines offered in competitors’ heavy-duty pickups. This heavy-duty engine also sets benchmarks for marine and industrial applications worldwide.

Introduced in the 2001 Chevrolet Silverado and Suburban and GMC Sierra and Yukon XL, the Vortec 8.1L was essentially a new engine. Nearly 90 percent of its parts were completely redesigned. While it shares its valve centers, bore centers and bore diameter with the previous 7.4L big block, stroke was increased 9.4 mm (0.37 inch) to increase displacement 700 cc. The latest math-based engineering tools were used to improve the flow and distribution of oil and coolant, to refine castings and to improve production quality and efficiency.

Power was increased for the 2006 Chevrolet Suburban, Avalanche and GMC Yukon XL 2500 Series, by reduced backpressure in the exhaust system, enabled by a new catalytic converter system. The new converter system is primarily designed to lower emissions. The new catalytic converter system has two new mid-coupled converters which replace four previous ones. The dual converters, with about two liters of volume, are also located closer to the exhaust manifold to enhance their effectiveness. While providing lower emissions levels, the new converter system also allows a more moderate 47.1 kPa of exhaust back pressure for more power. Induction restriction was unchanged.

Also for 2006, the 8.1L V8-equipped Chevrolet Suburban, Avalanche and GMC Yukon XL 2500 Series received an improved electronic throttle control pedal and improved throttle actuator control (TAC) module. The throttle pedal provides more consistent truck-to-truck pedal force and effort feel for vehicle operators. The TAC is designed to accommodate the new pedal. Located on the engine side of the front of the dash, the TAC module is an integral component of the Vortec 8.1L’s electronic throttle control (ETC) system. The TAC takes command from the powertrain control module (PCM) and then operates the motor that opens and closes the throttle plate. Like its predecessor, the TAC module has read-only memory and control software. It allows multiple throttle progressions or algorithms, which operate the throttle at varying rates according to operating conditions and driver demands. It also has built-in default settings that protect the engine and ensure safe operation in the event of malfunction with the ETC or other engine subsystems.

The Vortec 8.1L’s P59 engine controller in medium duty trucks was recalibrated for 2006 to coordinate with the newly available version of the Allison five-speed automatic transmission and the returnless fuel injection system (see below). The P59 also has new calibrations to optimize driveability and fuel economy with the new Allison six-speed automatic transmission being introduced for the first time in GM full-size pickups.

Finally, for 2006, the Vortec 8.1L available in Chevrolet Kodiak and GMC Topkick medium duty trucks was equipped with a new "returnless" fuel injection system that eliminates fuel return lines between the engine and the gasoline tank. The new fuel system is also known as a demand system. The system is already used with the Vortec 8.1L on Chevrolet Silverado and GMC Sierra models and with all Vortec 8.1Ls built for marine applications.

Before 2006, the Sequential Fuel Injection (SFI) in medium duty trucks equipped with the Vortec 8.1L used a return line to manage fuel pressure by bleeding off excess fuel at the fuel rail and returning the excess to the fuel tank. The new system eliminates the return lines and moves the fuel-pressure regulator from the fuel rail on the engine to the fuel tank. But because the returnless system delivers only the amount of fuel needed by the injectors, and returns no fuel to the fuel tank, it eliminates heat transfer from the engine to the fuel tank. This reduces the amount of vapor generated in the tank and captured by the evaporative emissions control system.

After extensive analysis of competitors' engines, the Vortec 8.1L development team set a goal of 200,000 miles of useful life without major repairs – and achieved it. Before it was ready for production, this big block had to pass the “Marine Dock'' test, in which it is run at full throttle for 300 consecutive hours without a failure, and a minimum of 1,000 hours at full-throttle operation for truck applications.

In the six years since its launch, virtually every aspect of the engine – from sealing to electronic management to noise, vibration and harshness control – has been re-examined and improved.

GM's leadership in big block V8 technology dates to at least 1958, when the Vortec 8.1L's progenitor was launched with 348 cubic inches of displacement in the full-size 1958 Chevrolets. The 348 was followed by several variants, including a 409, 366 and 427. In 1970, the 454-cubic-inch big-block was introduced. It was retooled in 1991 as the Vortec 7400 – a truly powerful pickup engine that met stringent 1990s emission requirements. The Vortec 8.1L bears little resemblance to those engines, but it maintains a tradition of outstanding durability and class-leading power.
The General Motors Vortec 8100 V8 was introduced in 2001 fullsize Chevy and GMC pickup trucks, RVs, vans, and SUVs as an alternative to the then-new Duramax diesel for customers seeking maximum hauling capability without the sourcing hassles and cost of diesel fuel. Also popular in maritime applications, the nautical version marketed by Crusader was branded Captains Choice, a great name if ever there was one. Of concern to car crafters, the Vortec 8100 (also known by its RPO number L18, but we'll just call it the 8100 in this story) was never offered in Chevrolet passenger cars because its hefty cast-iron heads and block bring total engine weight to 761 pounds.

But there is still a strong following among light-truck and SUV enthusiasts, even though the 8100 has been out of production (for highway use) since 2010. And, yes, more than a few Camaros, Chevelles, Corvettes, and Novas have been treated to 8100 power at the hands of builders seeking something out of the ordinary. These guys inevitably turn to lightweight aluminum heads from the aftermarket to shed weight. The resulting 500-plus-incher may not rev to 7,000 rpm like an LS, but with another 150 lb-ft of torque off the line, who needs revs? Check around, 8100 swaps have become popular with a host of car builders looking for something different.






Back to the history lesson, the 8100 was part of a final wave of domestic, gas-burning truck engines that included the 1994 8.0L Dodge V10 and 1997 6.8L Ford V10. Volatile gasoline prices conspired with advances in diesel engine technology like direct injection and refined turbo systems to make these oil-burners more appealing than ever. This slashed demand for these comparatively thirsty gasoline powerplants, and only the Ford V10 remains in production today. Dodge pulled the V10's plug after 2003 (except for Vipers), while the last Vortec 8100 was assembled in December 2009.


The nautical version marketed by Crusader was branded Captains Choice, a great name if ever there was one.
While Dodge and Ford added cylinders to get the necessary displacement, for the Vortec 8100, GM simply took the venerable 454 big-block V8 crankcase and gave it a shot in the arm. Though not officially designated as such by the factory, enthusiasts refer to the 8100 as a Gen 7 big-block because it borrows from the Gen 6 454/502 heavily. Call it what you will, the 8100 was the result of GM bumping the Vortec 7400/454's 4.00-inch stroke to 4.37, thanks to longer connecting rods and a block with taller decks. Sharing the 454's 4.25-inch bore, a burly 496 ci resulted. Being a heavy-duty, truck-specific engine, four-bolt main bearing caps are used, but unlike traditional high-performance 396 through 502 blocks—where the end caps (numbers 1 and 5) got the usual two bolt caps—the 8100 takes it all the way with four-bolt caps at every location (like many diesels).

If all of this makes builders of traditional rat motors drool with visions of inexpensive 600-cube torque monsters based on recycled 8100 blocks, beware. Changes were made to the block's oil-pan rails, all fasteners are Metric, and the 18-point head-bolt pattern (two more than the 396–502) is radically different and doesn't begin to accept factory or aftermarket big-block heads. Thus, the 8100 block isn't of much use to traditional Chevy big-block builders, but as we'll see, all is not lost.

And about those heads; though an assembled 8100 may not look much different from the 454-based Vortec 7400 it replaced, the intake ports were radically reworked. Since its debut in 1965, the Chevy big-block's canted valves delivered excellent breathing characteristics, thanks to the moving valve head's trajectory away from the shroud-inducing cylinder wall. But due to the need to allow space for things like pushrods, water jackets, fastener bosses, and intake ports, non-symmetrical, siamesed intake ports resulted. In short, the engine inhales through two distinctly different-sized intake runners: two short and two long. The symmetrical exhaust ports are less compromised, but there was room for improvement in both areas.

gm-vortec-8100-v-8-engine.jpg
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Improvement came from the LS1. One look at the tall, thin cathedral intake ports first used on the 1997 LS1 cylinder head will show that their designers were fixated on symmetry. By focusing on shaping the ports as close as possible to each other in terms of size, contour, volume, and flow capacity, the density and velocity of the intake charge entering each cylinder is closer to equal. The resulting cylinder pressure during combustion is then equalized—as are the spent gas-evacuation characteristics during the exhaust stroke—and a more efficient engine results. That the LS1 (and subsequent Gen III small-blocks) are potent is an understatement.

For the 8100, GM designers cast aside the big-block's traditional long-port, short-port intake design and applied the LS1's strategy of making each intake and exhaust port as close to the rest as possible. With the intake manifold removed, the 8100's evenly spaced intake-port openings are a foreign sight compared to the traditional siamesed ports of previous big-block heads. What worked on the LS1 also worked on the 8100, though as a truck-oriented workhorse, GM concentrated on low- and midrange torque production, so don't expect to see fist-sized orifices.

More than a few Camaros, Chevelles, Corvettes, and Novas have been treated to 8100 power at the hands of builders seeking something out of the ordinary.
The big-block's traditional canted valve layout was retained because it still works. So yanking an 8100 valve cover reveals the big-block's non-linear, "porcupine," valve-stem configuration and stud-mounted rocker arms. Overall, GM did a fine job of giving the "Rat" a new lease on life. But at 340 net horsepower in stock trim, there's plenty of unexplored potential on tap.

We recently got a call from Patrick Davis, owner of a 2006 Chevy Avalanche, who turned us on to the world of 8100 performance modifications, thanks to an engine rebuild performed by James Bostick and the guys at Bostick Racing Engines in El Cajon, California. It turns out there are lots of frustrated 8100 owners—on land and sea—who need more than 340 hp and 450 lb-ft of torque, but don't want to turn to diesels. They all go to Raylar Engineering for help. Raylar is the go-to shop with a full line of available rotating assemblies, camshafts, valvetrain and intake-manifold upgrades and even a line of Big Power aluminum cylinder heads. Raylar's website even shows how to swap an 8100 into a C3 Corvette! Let's dig in and see how Pat's Avalanche has improved.



gm-496ci-vortec-8100-v-8-engine.jpg
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The 496ci Vortec 8100 appeared in 2001 as a replacement for the 454ci Vortec 7400. The 8100's 42 extra cubes, siamesed intake ports, and other improvements delivered 340 hp and 450 lb-ft of torque in stock trim. The outgoing 454 rated 290 hp and 410 lb-ft. This 2006 Chevy Avalanche's owner needed even more and put Bostick Racing Engines on the job.

gm-496ci-vortec-8100-v-8-engine-block-main-caps.jpg
4/21
The 8100 block bears external 8.1L markings for quick identification. With four-bolt main caps in all five positions, bottom-end strength is abundant and all-out builds can easily handle 7,000 rpm. Lacking a distributor-mounting hole, the factory crank trigger ignition is retained to fire the plugs. The 8100's main cap bolts torque to 110/100 lb-ft (inner/outer) at all locations. Believe it or not, the 8100 block is 20 pounds lighter than a 502 due to its thin wall casting.

raylar-engineering-stroker-kit.jpg
5/21
The dominant source for upgraded 8100 parts for land and sea use, Raylar Engineering offers everything needed to transform the 8100 into a stormer. The Raylar 4.75-inch stroker kit bumps displacement to 547 cubes using all forged rotating parts. Stock 8100 cranks and pistons are cast with powdered metal rods. Raylar's kit uses all forged parts and hard-anodized piston skirts with anti-friction coatings. The rotator can handle 800 hp and even turbocharging. Note the crank position tone ring at the tail of the crank (left).

gm-496ci-vortec-8100-v-8-engine-cylinder-barrels.jpg
6/21
The Avalanche block's seasoned bores are enlarged 0.030-inch to 4.280 to eliminate existing wear. The bottoms of the cylinder barrels require modest notching to clear increased swing arc of rods. Swapping 8100s into classic Chevys with manual transmissions requires a hydraulic clutch actuator. The 8100 block lacks the threaded receptacle for clutch pivot ball.

gm-496ci-vortec-8100-v-8-engine-with-raylar-540-stroker-assembly.jpg
7/21
The Raylar 540 stroker assembly grows to 547 with the 0.030-inch cylinder overbore. Swappers love the 8100 block for its combination of LS style and traditional motor-mount bosses. The dual circular holes tapped into the oil-pan rail ahead of the oil-filter pad connect to factory-stock external oil-cooler circuitry. The wider oil-pan rail doesn't accept non-8100 oil pans. Truck pans swapped into cars are aluminum and require modifications to fit.

raylar-big-power-cnc-aluminum-heads.jpg
8/21
Stock 8100 cast-iron heads weigh 78 pounds each and are not interchangeable due to a front-mounted coolant transfer tube. Raylar's Bigpower CNC aluminum heads weigh less than half that and interchange from side to side. Port flow at 0.300-inch lift is 240/176 cfm (I/E), 0.400 lift yields 295/201 cfm, 0.500 lift yields 330/229 cfm, and at 0.600 lift you'll see 341/252 cfm. More than 400-cfm flow numbers are possible with the CNC Extreme head option.

The resulting 500-plus-incher may not rev to 7,000 rpm like an LS, but with another 150 lb-ft of torque off the line, who needs revs?
raylar-intake-ports.jpg
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At 315 cc, Raylar intake ports are significantly larger than stock 8100 heads (see sidebar). Raylar also embraced the LS-style, high-velocity, symmetrical intake-port configuration to feed its 2.19-diameter EV8 stainless intake valves. Manganese-silicon bronze valve guides and hardened steel valve seats are ready for anything from trailer hauling to turbocharged dragstrip duty.

raylar-exhaust-ports.jpg
10/21
Like the stock 8100, Raylar retains the good D-shaped exhaust port but with a larger 135cc volume. Exhaust valves measure 1.750-diameter and share necked 11/32 valve stems with intake side. Both seats feature a five-angle competition valve job. Optional CNC Extreme heads use 2.25/1.88 valves and extensive CNC porting to boost flow.

raylar-aluminum-heads-combustion-chambers.jpg
11/21
Like GM, Raylar's aluminum heads retain the benefit of the big-block's stock canted valve arrangement, as well as the stock guideplates and rocker studs. Fully CNC-machined 107cc combustion chambers bring compression ratio to 10:1 (9:1 is stock). Extra-thick 5/8-inch cylinder head decks ensure rigidity; the factory iron head decks are ½ inch.

raylar-aluminum-heads-with-double-valvesprings-and-chromoly-retainers.jpg
12/21
Up top, the Raylar Big Power castings come with double valvesprings and chromoly retainers providing 140 pounds on the seat at 1.900-inch installed height and 380 pounds at 0.600-inch lift. Stock 8100 valve covers must be used since the bolt pattern is different than traditional big-blocks—more on that in a moment. Beware, the stock 8100 is an all-Metric engine and its stock fasteners are all one-time-use, torque-to-yield items.

raylar-hydraulic-roller-cams.jpg
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The 8100's LS-style port spacing and 1-8-7-2-6-5-4-3 firing order prevent the use of traditional big-block camshafts. Raylar honcho Larry Hofer says he's invested too much dyno time to give away the ideal cam specs. Thus, Raylar offers nine proprietary performance-proven hydraulic roller cams to suit applications from trailer towing to turbocharged drag racing. This trio depicts (left to right) the 203 (high-torque, stock-idle quality, emissions-compliant, safe with stock piston crowns), the 206 (for stock displacement or strokers with deep-relief pistons, choppy idle, 2,500-rpm stall recommended, improved midrange and top-end power), and the 213 (high lift, choppy idle, ideal for extra-displacement applications, requires Raylar deep-relief pistons). We pried, but all Hofer would say was that valve lift ranges between 0.500 and 0.660 lift. Call Raylar to make sure your pistons and cam are safely matched. Our 547 Avalanche runs the 206 cam. One benefit is the stock GM roller lifters can be reused if they're healthy.

gm-496ci-vortec-8100-v-8-engine-with-raylar-heads.jpg
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Seasoned big-block builders will note the shortness of the Raylar chrome-moly rocker arm stud assemblies. The total installed height is low enough to fit beneath the stock 8100's pancake valve covers. The Raylar 1.7:1 cast stainless roller rockers gain 18 hp versus stock 8100 scrubber-type rockers. The top timing gear does double duty as cam position sensor trigger. Three gear and sensor assemblies were used (2001, 2002–2003, and 2004-up), so contact Raylar to ensure you've got the right parts. The head bolts torque to 55 lb-ft (long), 50 lb-ft (short), and with six fasteners clamping the gasket's fire ring around each bore, the 8100's gasket seal is unsurpassed in stock rat motor block history.

raylar-modified-manifold.jpg
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The stock cast-aluminum 8100 intake manifold and 73mm throttle-body were meant for hauling and suppress airflow and power above 4,000 rpm. To complement our 547-cube long-block, Raylar offers this modified manifold with removed internal dividers, port matching, and a 90mm throttle-body for increased flow and power with the rpm ceiling climbing to 5,000. The stock 27-pound fuel injectors were at maximum duty cycle and gave way to Delco 42-pound squirters. All-out applications can make use of Raylar's fabricated aluminum Cool-Gap intake manifold or even a vertical eight-stack manifold with individual runners and ram tubes. When uncorked with these manifolds, crank speeds approaching 7,000 rpm are possible in all-out builds.

jba-headers.jpg
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Perched on the engine stand, the completed 547-cube Vortec mill wears equal-length headers from JBA Headers. Designed for 2001–2006 8100-powered trucks, they're superior to stock manifolds and feature 2-inch primary tubes, 3-inch collectors, and are CARB approved. They cooperate with factory head pipes and catalytic converters for easy installation. Note the 8100's coil-near-plug ignition layout. The white ceramic spark-plug boots can withstand 2,000 degrees and are available from Raylar to prevent burned wires.

reprogrammed-ecu.jpg
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Once installed in Davis' Avalanche, Bruce Tucker and the crew at JBA Speed Shop reprogrammed the ECU, then strapped the beast to their Mustang chassis dyno. If you're wondering how a 4x4 truck gets tested on a rear-wheel-only chassis dyno, thank the Avalanche's 4x4 on/off switch! The stock 8100 uses the same ECU as many LS engines (PN 12200411 and popularly referred to as the 0411), so reprogramming is no mystery. JBA updated the fuel trim, spark table, torque management, and the self-learning properties took it from there. Not used in Corvettes or Camaros, the truck-only, torque-management function retards timing to protect the transfer case against damage in extreme off-road situations. Passenger cars (fortunately) lack this detail.

dyno-results.jpg
18/21
The notoriously conservative Mustang chassis dyno delivered the news. Jumping off from the stock readings (220 hp at 3,940 rpm and 303 lb-ft at 3,400 rpm), the 51 extra cubes, free-breathing heads, greater cam timing, and hogged-out intake manifold brought 110 hp and 115 lb-ft to the party (330 hp at 4,600 rpm and 418 lb-ft at 4,000 rpm). Imagine this monster in a light Camaro or Nova!

Overall, GM did a fine job of giving the "Rat" a new lease on life. But at 340 net horsepower in stock trim, there's plenty of unexplored potential on tap.
Symmetrical Rat
A Look at the 8100 Cylinder Head

stock-combustion-chambers.jpg
19/21
The stock, 114cc, heart-shaped combustion chambers were designed for a 4.50-inch bore (the 8100 bore measures 4.25). The chambers overlap the 496's bores, which shrouds the stock 2.190/1.725-inch valves. Raylar's Big Power heads use smaller chambers to eliminate the shrouding problem. Raylar also added another quench area adjacent to the spark plug, which promotes faster combustion.

stock-intake-ports.jpg
20/21
Tall and skinny, the stock 8100 intake ports borrow from LS architecture and are virtually identical from cylinder to cylinder. The classic big-block's two short and two long intake-runner strategy was a compromise. Unfortunately, the 8100's extreme focus on thin wall casting for reduced weight prevents meaningful porting work, particularly at the short side radius, where help is most needed.

exhaust-ports.jpg
21/21
The 8100 head retains the D-shaped exhaust-port configuration first employed in 1979. Shown upside-down here, the concept is good, but the size is too small for high horsepower. Each cast-iron 8100 head weighs 78 pounds bare. Since the stock valvetrain is strictly non-adjustable, when swapping cams, be sure the stock base circle is retained to ensure proper lifter preload.


http://www.lowmileageparts.com/2002...gclid=CI60pMKoxNACFVE7gQodbcEEMQ#.WDhlV-YrLcc

http://www.powertrainproducts.net/C...E-p/1173.htm?gclid=CMu12e6oxNACFVMvgQodsXMC6w

http://www.raylarengineering.com/index.html

http://www.karlperformanceparts.com/p/89017618-8-1L-L18-GM-Crate-Engine/708
 
Last edited by a moderator:

chromebumpers

solid fixture here in the forum
Staff member
Update Grumpy. The 8100 Vortec is a hot commodity now and much more is available in the past 2 years for power ad-ons. Ad a supper charger kit (compression is just about right for it) along with performance heads,headers and programming and you're looking at over 700 hp. It's a bit expensive to swap in an 8100. At an average $5,500 on eBay, you can easily spend another $7,000 for the above mentioned parts plus the change-over to install parts will be about $1,000 more. I know the weight difference is between an LS Aluminum block and LS iron block is 88 lbs. - I don't know the weight difference between the 8100 and the all aluminum LSX's, maybe near 150 lbs.?
 
8

87vette81big

Guest
Already at the New Baseline 900 Hp from Hellcats. 9-second ET 1/4 Mile .
 
8

87vette81big

Guest
Bone stock is fine for most.
Only a few can compete with Hellcats.
Little point trying unless all out effort.
 
8

87vette81big

Guest
I kind of get the feeling you might have a thing for Hellcats Brian?
Because I have been there before.
Myself and my 70-1/2 T/A Against all 10 & 9-Second Chevies local.
Its a Street Racing Hero Game action.
Real Life.
I warned all last year 2014.
Only Junkman on DC Listed to me.
Too late for most. Not me.
 

chromebumpers

solid fixture here in the forum
Staff member
In the pictures above, why the really high valve covers, the valve-train doesn't need anywhere near that much room?
 

chromebumpers

solid fixture here in the forum
Staff member
It's funny how things work out. I bought a tailgate last week from a salvage yard employee and I asked him to let me know when the next LSX engine comes his way. Last night he called to tell me he has an 8100 that just came in still in a rear wrecked Avalanche. I never knew those came with that engine. It's $1500 with 90,000 miles. My only fear is I think he yanks engines out the butcher way, not like the resellers on the Internet that are very professional and follow the GM manual and factory trained tech ways. Trust me, there is a big difference!
 
8

87vette81big

Guest
It's funny how things work out. I bought a tailgate last week from a salvage yard employee and I asked him to let me know when the next LSX engine comes his way. Last night he called to tell me he has an 8100 that just came in still in a rear wrecked Avalanche. I never knew those came with that engine. It's $1500 with 90,000 miles. My only fear is I think he yanks engines out the butcher way, not like the resellers on the Internet that are very professional and follow the GM manual and factory trained tech ways. Trust me, there is a big difference!
Tell the guy you will pay extra if nothing is butchered.
$100 more.
 

chromebumpers

solid fixture here in the forum
Staff member
Tell the guy you will pay extra if nothing is butchered.
$100 more.
That's too funny! I already sent him my instructions and told him he will get an extra $250 AND I bet when done by the book it will save some time! I hate like hell when theses junk yard guys snip off wires and ship accessories that should be kept sealed but instead drain drip-dried and left open!
 

chromebumpers

solid fixture here in the forum
Staff member
The new power steering is areal pita to re-bleed and be like factory feeling and quite after it's been drained!
 
8

87vette81big

Guest
That's too funny! I already sent him my instructions and told him he will get an extra $250 AND I bet when done by the book it will save some time! I hate like hell when theses junk yard guys snip off wires and ship accessories that should be kept sealed but instead drain drip-dried and left open!
They are Junkyard Guys. Motivated by $.
The Young helpers are LAZY..............
 

chromebumpers

solid fixture here in the forum
Staff member
Yeah, they rip and tear away like a gorilla! I stood back watching once while the guys were removing an LS6 from a wrecked '04 Z06. I complained and the boss threw me out, I guess they had someone else who would pay more ( it was kind of cheap but certainly not worth replacing what they were screwing up).
 
8

87vette81big

Guest
Yeah, they rip and tear away like a gorilla! I stood back watching once while the guys were removing an LS6 from a wrecked '04 Z06. I complained and the boss threw me out, I guess they had someone else who would pay more ( it was kind of cheap but certainly not worth replacing what they were screwing up).

Its hard to correct Stupid Richard.
If management is Dumb then.....
 

Grumpy

The Grumpy Grease Monkey mechanical engineer.
Staff member
http://www.hotrod.com/features/1509-how-to-find-an-8-1l-big-block/?cx_source=cxrecs#cxrecs_s
o you’ve decided you want an 8.1L engine in your muscle car or your tow rig, and who can blame you? They make more torque at 800 rpm than a factory LS1 produced at any point in its rpm range. Because they were also intended for marine and medium-duty truck use, they were subjected to grueling development tests, including the “Marine Dock” test that involves running the engine at full throttle for 55 minutes and then idling if for five minutes, 300 times. In other words, they’re incredibly durable.

With both Ford and Dodge dropping big-blocks in favor of V10 gas engines for their heavy-duty trucks, GM was the last OEM to produce big-block passenger vehicles into the 21st century, and the 8.1L had many of the advancements that make GM’s Gen III small-blocks so successful. The factory fuel-injection system and engine diagnostics are more advanced, their cylinder-head ports are similar to the cathedral ports you’d find on an LS1—only larger—flowing around 285 cfm on the intake. They also use coil-on-plug ignition with a crank trigger for accurate spark timing. With those improvements, they still use the same engine mounts, bellhousing bolt pattern, exhaust bolt pattern, and starter that are found on a traditional big-block, making bolting one into your car or truck relatively straightforward. But where to find one?


2001–2002 GM 3500HD trucks. There were carryover chassis cabs that used the 1988–1998 body style.

2001–2002 Chevrolet Express/GMC Savanna vans.

2001–2006 Chevy and GMC 2500/3500 trucks and Suburbans.

2001–2009 Chevy Kodiak and GMC TopKick medium-duty truck, option code LRW.

Mercury and VolvoPenta marine applications.

Industrial generator and pump applications.

2/2
- Light-truck and SUV applications will be the easiest to find, and they’re the best bet for a complete engine if you don’t plan on using air conditioning. Unfortunately, their accessory brackets mount the A/C compressor low on the passenger side, which is likely to interfere with the frame.

2015 Honda Accord
www.Honda.com/Hyundai_Sonata
Compare Side by Side:
Performance, Specs, Price & More.
- If you want air conditioning, the accessory drive from a Kodiak or TopKick will be the best bet. Engines with option code LRW mount the A/C compressor high on the driver side. The air-brake-equipped trucks with option code KDZ will mount it high on the passenger side. You can eliminate the brake air compressor and its related idler and reroute with a shorter serpentine belt.

- While they look like they’d fit, the accessory system from a Vortec 454ci V8 will not bolt to the 8.1L’s heads.

- Marine, industrial, and medium-duty trucks use massive oil pans. The rear-sump, light-duty truck pans are much more swap-friendly.

- The factory valvetrain is non-adjustable, so you’ll probably want new rocker studs to allow for adjustable rocker arms.

- The light-truck and SUV applications moved to a returnless-style fuel system in 2004, marine applications followed in 2005, and the medium-duty trucks followed in 2006. Returnless systems don’t heat up the fuel as much and there’s less plumbing, but the earlier systems allow for easily adjustable fuel pressure. If you want more power with the stock injectors, the return style is the way to go.

- 2004 engines eliminated the EGR system with tuning changes that made it obsolete. 2004 also included more durable crank and cam timing sensors that are the same as those used on the Gen III small-block, making them more likely to be stocked in your local parts store.

- Look out for industrial applications of the engines, as they use different valvesprings meant for low-speed operation. The 2004-and-later industrial 8.1Ls use the same valves as the truck applications, so only the springs need to be updated.

- If you want a cable-actuated throttle, a spacer can allow the use of a Vortec 454 throttle-body.
 
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