Читать книгу Swap LS Engines into Chevelles & GM A-Bodies - Jefferson Bryant - Страница 7
ОглавлениеMODERN V-8 MASTERPIECES: THE LS- AND LT-SERIES ENGINE
Development for the Gen III engine began in 1991 after the short-lived LT1/LT4 engine failed to meet GM’s performance expectations. General Motors essentially started from square one to create the new Gen III V-8 engine, which shared very little with the original small-block Chevy LT1/LT4 platform that it replaced. A phenomenal high-performance engine, the Gen III LS1 showcased modern engine technology while retaining the traditional pushrod valvetrain. The engine first appeared as the flagship engine in the 1997 Corvette, generating a groundswell of enthusiast interest. A series of high-performance Gen III/Gen IV engines followed it.
An assembly technician installs components on each Gen III/IV powerplant. All Gen III/IV engines are distributorless, and all but one are fuel injected. If you are buying a used engine, you need all the wiring and electronics for almost every engine swap, unless you are going to use an aftermarket controller. (Photo Courtesy General Motors)
Although many refer to these as “LS” engines, the official nomenclature is Gen III and Gen IV. These remarkable engines produced class-leading performance and fuel efficiency. Street rodders, muscle car enthusiasts, and even sports car aficionados recognized the potential of the potent, compact V-8s and sought Gen III/IV engines for swapping into a wide range of vehicles. The factory small-block engines pushed out 350 hp at the low end of the scale and reached more than 500 hp at the top end. It seemed the horsepower wars from the late 1960s were back again. In addition, Gen III/IV engines transformed Chevrolet Performance’s marketplace and they released a full complement of high-performance parts for these powerhouse engines.
The desire to swap these engines into other vehicles is at an all-time high. Finding an LS engine for your project can be as simple as a stroll through the local salvage yard, a website visit, or a phone call to your local dealer. You can select a “take-out” engine from a damaged or totaled vehicle in a salvage yard, build an engine from component parts, or pick out a crate engine with a warranty from many different LS engine dealers and Chevy Performance. Many different models of these venerable engines are available from a variety of sources.
Gen III: A Revolution in V-8 Performance
All aluminum and cast-iron blocks built from 1997 through 2004 are basically the same. However, there are some minor differences within this time frame, including an important internal difference. The outside diameter (OD) of the camshaft bore was changed in 2004. Although the cam itself remained the same, the bearing OD changed, and required a different set of cam bearings.
General Motors utilized the Gen III platform for the full range of GM trucks. With two years of experience under its belt, General Motors replaced the aging Gen I 305 and 350 small-block truck engine platform with Gen III engines. The new truck and SUV powertrain was offered in three displacements: 4.8-, 5.3-, and 6.0-liter. These V-8 engines were installed in every GM truck and SUV from 1999 to 2007. The 4.8- and 5.3-liter engines have the same aluminum cylinder heads. The Vortec truck engines have proven to be a popular swap because of their abundant availability. You can pick up a Vortec Gen III for next to nothing.
The scalloped holes at the top right side of the main webs on the block illustrate the crankcase breathing holes. This promotes proper ventilation for the air and oil vapor in the Gen III/IV engines. (Photo Courtesy General Motors)
In 2005, when the Gen IV platform began replacing the popular Gen III, the evolution in pushrod engine technology took another step forward. Based on Gen III architecture, these new engines took advantage of displacement-on-demand (DOD) technology, which General Motors called Active Fuel Management (AFM). With AFM, the engine alternates firing of the pistons among all eight to as few as four pistons, saving fuel and reducing emissions. Although the technology has been offered on the Gen IV platform, this engine series was designed to accept Variable Valve Timing (VVT) and to accept three valves per cylinder.
But that did not mean the Gen III disappeared from production in 2005. The LS1 was still in production for the Holden VE and W models and the LS6-powered Cadillac CTS-V, while the Chevy Performance division continued to offer both engines. In fact, Gen III engine production continued for new vehicles until 2005 when two all-new engine platforms were released: the Gen IV LS2 and LS4.
Pumping out 505 hp, the LS7 was the first dry-sump LS engine, and it’s a favorite for swap projects because you don’t have the oil pan clearance issues that you have with a wet-sump engine. In addition, this fourth-gen engine is one of the most powerful naturally aspirated engines and is standard equipment in the Corvette Z06 and Camaro Z28. (Photo Courtesy General Motors)
Cadillac and Chevrolet needed an engine to turn the CTS-V and ZL1 Camaro into street demons, so General Motors came up with the LSA. The slightly smaller Eaton supercharger reduces the overall output to 556 hp compared to the LS9. The LSA is also available as a crate engine. (Photo Courtesy General Motors)
The LS9 is the ultimate LS powerplant, making 638 hp with the intercooled supercharger. When it was released, it was the most powerful production engine ever made by a U.S. manufacturer. It was installed in the ZR1 Corvette and the ZL1 Camaro. The 6.2-liter engine is available as a crate engine from GM Performance. (Photo Courtesy General Motors)
In 2014, General Motors introduced the LT1, the next evolution in small-block pushrod engine technology. Upgraded from the LS-series, the LT-series engines share some basic architecture, but are a completely new line of engines.
The biggest advancement in the LT series is direct injection. Similar to diesel fuel systems, the mechanical pump pressurizes the fuel to more than 2,000 psi and injects it directly into the combustion chamber, ensuring there is no issue with atomization and yielding absolute control over the engine’s fuel use. (Photo Courtesy General Motors)
In 2006, the LS7, the ultimate Gen IV engine, was installed in the Corvette Z06 and made quite an impression in the high-performance community. This fire-breathing small-block produced 505 hp and earned the distinction as the most powerful naturally aspirated production small-block Chevy engine ever built. In 2005, the truck engine line changed to the Gen IV platform, adding six new Gen IV blocks. By 2008, the 6.0-liter L76 and the 6.2-liter LS3 joined the Gen IV line. With the popularity of the Gen III and Gen IV engines, General Motors developed specially for the aftermarket the LS364 carbureted Gen IV engine and the LSX bare block for retrofitting and swapping.
To further push the Gen IV performance envelope, General Motors stepped up its game with two new ultra-high-performance engines to stay on top of the late-model horsepower wars: the LSA and the LS9, both based on the LS3 block.
The LSA is a supercharged 6.2 liter that utilizes a 1.9-liter roots-type Eaton supercharger to build 556 brake hp (flywheel) and 551 ft-lbs of torque. The LSA is available in the 2009–up Cadillac CTS-V models as well as the 2012–up ZL1 Camaro.
The LS9 also measures 6.2 liters, but uses a 2.3-liter Eaton Roots blower to generate the 638 bhp and 604 ft-lbs of torque, making it the most powerful GM V-8 ever produced. Just like the LS7, the LS9 features a 10.75-quart dry-sump oiling system. The LS9 is used in the 2009–2013 Corvette ZR1.
In 2013, General Motors released the Gen V platform and adorned it with the LT-series designation. Although not to be confused with Gen II Chevy small-blocks, this engine series will eventually replace the LS-series engine in all platforms. The Gen V shares the look of the III/IV series, but is an all-new engine platform. The LT series’ biggest advancement is the use of direct injection. With this system, fuel is sprayed directly into the combustion chamber at high pressure (2,175 psi for the LT1), increasing fuel economy and overall performance through better fuel atomization. Direct injection also makes cylinder deactivation more efficient, further increasing fuel economy. The 2014 LT1 Corvette can achieve as much as 29 mpg. Other advancements include piston-oiling jets, active fuel management, and continuous VVT.
General Motors wasn’t going to stop there, as it brought out the LT4 in 2015. This is a supercharged version found in the Corvette Z06. The biggest differences from the LT1 to LT4 are lower compression and slightly stronger pistons and rods to handle the additional boost. (Photo Courtesy General Motors)
Chevrolet Performance has released two crate versions of the Gen V: a naturally aspirated 6.2-liter 460-hp LT1, which is the same engine installed in the base-model C7 Corvette, and the supercharged 6.2-liter 650-hp LT4, which comes in the Z06 version of the C7 Corvette. The LT1 for Camaros is rated at 455 hp.
6.2 LT1
Making 460 hp without a supercharger is not easy, and to do so while hitting 29 mpg is even harder, but the LT1 does exactly that. The 4.06-inch bore combined with the 3.62-inch stroke creates an 11.5:1 compression ratio, which makes efficient use of the fuel pumped through the direct-injection nozzles. A forged crank, hypereutectic pistons, and forged powdered-metal rods yield light weight and durability. The heads are conventional aluminum castings that feature lightweight sodium-filled valves.
6.2 LT4
To increase the output of the LT1, General Motors dropped a supercharger onto the 6.2 block to make 650 hp. To make that work long term, changes were made to the rotating assembly. The crank is the same, but the rods were slightly redesigned to increase strength in key areas. The LT4’s pistons are forged and the combustion chamber was opened up, decreasing the compression ratio to a boost-friendly 10.0:1. The rotocast heads are stronger and better at handling higher heat ranges than a typical cast head. The valves are solid titanium and the oiling system is a dry-sump design.
Starting in 2014, all GMC/Chevrolet trucks and full-size SUVs with V-8 gasoline engines come with Gen V engines. Currently three truck versions are available: 4.3 (LT-based V-6), 5.3 V-8, and 6.2 V-8. The V-6 is an LT-series engine, essentially a V-8 with two cylinders cut off. The V-8s are the most common for trucks and SUVs.
5.3-liter L83
This engine features a 3.78 bore with 3.62 stroke. These engines make 355 hp and 383 ft-lbs of torque with gas, while producing 376 hp and 416 ft-lbs of torque with E85.
6.2-liter L86
The L86 is a modified LT1, making 420 hp and 460 ft-lbs of torque. The LT1 and L86 are very similar, down to the compression ratio of 11.5:1.
The purpose of most engine swaps is to increase performance. In almost all cases LS engines meet performance goals. Because the Gen III/IV engine platform represents the largest growing segment of the performance automotive aftermarket, many options are available for increasing the performance of an LS-series engine. Simple bolt-on components include items such as larger throttle bodies or high-flow intakes; serious performance upgrades include items such as high-lift camshafts and large-port cylinder heads.
Although the factory equips its high-performance LS engines with superchargers, a turbocharger is the most effective big-boost upgrade you can install. Driven off exhaust rather than drive belts, a turbo provides “free” horsepower. A 5.3 Vortec engine with a single turbo can make more than 500 hp with no other mods (other than a tune).
With so many options to choose from, Gen III/IV engine swaps have become more and more popular. Once you know where to find the engine that best suits your needs, performing the swap is the next step. The rest of this book deals with how to do this and covers most of the details. Although every car and swap is different, several aspects are common to all.
Swapping an LS-series engine is not the most complicated automotive endeavor. An average swapping project is fairly easy if it is carefully conceived, researched, and planned. The Gen III/IV engine families have footprint similar to the original small-block Chevy. If a traditional small-block Chevy can be swapped into a vehicle, you can certainly install an LS engine, but some minor adjustments such as re-arranging the drive pulleys and other components may be required. The possibilities are truly endless when it comes to LS swaps.
Although most builders are familiar with carburetors and how they work, fuel injection systems, computers, and wiring harness hookups intimidate many swappers. Electronics are a critical component of any swap. In most cases, you must carefully modify wiring harnesses, plugs, and wiring, or purchase the correct aftermarket components for plugging in the particular engine to a specific car. Shops such as Painless Performance provide the products and support to help simplify the wiring harness. Tuning companies such as HP Tuners and EFI Live can reprogram the engine control module (ECM) to adapt it for a swap. In the end, you have a more efficient powerplant with the ability to tune it better and faster.
You can install a carburetor on an LS engine, such as an LS364, and eliminate a big chunk of the electronics. In addition, you can use an aftermarket carbureted intake designed for LS-series engines. LS engines with carburetors are just as powerful and still take advantage of the electronic spark distribution using the one-coil-per-cylinder design. You still need a spark controller, though, because these engines do not have a provision for a traditional distributor, but these control boxes are very easy to wire up.
One of the biggest benefits of the new Gen III/IV engines is their efficiency. They were designed to meet strict Corporate Average Fuel Economy (CAFE) standards for new vehicles. These engines manage to meet fuel economy ratings while making significant horsepower numbers. In the past it was not possible for a small-block Chevy to make 400 hp and get 20 mpg. With an LS engine, it is not only achievable, it’s standard.
The 2013 Z06 Corvette has an LS7 that cranks out 505 hp and maintains 24 mpg highway and 15 mpg city for a combined 18-mpg average. A Gen I small-block Chevy cannot get close to those numbers. A stock Vortec 5.3-liter with an overdrive automatic can produce 350 hp and 20 mpg with a custom ECM tune.
These factors combined make the Gen III/IV engines the most popular swap since the original small-block Chevy hit dealers in 1955. With so many variations, there is sure to be a Gen III/IV engine to suit your application.
One of the most popular swaps is the 1964–1972 GM A-Body platform. This generation of vehicles covers every GM make (except Cadillac) and features the most popular muscle car models. These include the Buick Special, Skylark, Sportwagon, and GS. Chevrolet cars are the Chevelle, Concours Estate Wagon, Nomad, Malibu, and El Camino. Oldsmobile models include the F85, Cutlass, Cutlass Supreme, Vista Cruiser, and Cutlass 442. Fiercely independent Pontiac A-Body cars are the Tempest, Safari, LeMans, and GTO. The differences among models means different requirements for installing an LS or LT engine, most notably the frame stands for the motor mounts.
Performance Project: The “Take-Out” Procedure for a Vortec 5.3-Liter Salvage Yard Engine
Although some swappers purchase crate engines or salvage yard take-out engines, you can save a lot of money by finding a wrecked vehicle and yanking the engine yourself. GMC and Chevy trucks are the most abundant source for LS-series engines, but it’s important to find one with less than 200,000 miles on the odometer. When properly maintained, an LS engine can make 300,000 miles before needing a rebuild. An LS engine with 150,000 or fewer miles usually has a lot of life left and does not require a rebuild.
For this project, I bought a still-drivable 2003 Chevy 1500 truck with rear-end damage. The engine and transmission ran well and it could have been repaired. However, it had a salvage title and was a bargain at $500, so I went ahead with the swap. I rolled the truck into the shop and began stripping it down by removing the fenders. Although removing the fenders isn’t required, it makes accessing all the bolts much easier and the truck is slated for the scrap yard anyway. Within 10 minutes the fenders were off.
Under the hood of this 2003 Chevy 1500 lies a dormant beast; well, a potent powerplant anyway. The 5.3 Vortec engine is the most commonly swapped LS engine. It is also the most abundant. Ripe for the picking.
First, I started removing the fenders and grille. Next, I disconnected the airbox and removed the shrouds.
I removed the fenders and hood to gain access to the engine without having to work around those parts. This is much easier. I disconnected the wiring and removed it from the engine. This included the computer, located on the driver-side inner fenderwell.
The hose can be removed or cut because it will not be reused. I did leave the A/C system intact, as those parts are good salvage parts and opening them to the atmosphere leads to damage.
Next, I removed the core support. You can leave the radiator in the car until you are ready to pull it. Two body bushings on the frame connect the core support with through-bolts; remove them. The fenders are attached to the core support with a couple of bolts as well. This opens the front of the engine, making removal from the chassis easier.
A lot of hoses and wires attach to the engine. The coolant needs to be drained; you can do this last if you prefer as it usually makes a mess. The A/C components (compressor, hoses, and condenser) can remain in the truck. You can’t use the stock A/C compressor in swaps, so there is no point in purging the gas from the system. Carefully remove each wire connector from the engine, cut any zipties or straps holding the harness to the engine or chassis (don’t cut any wires!), and remove the harness. The hoses can be removed or simply cut because you need new hoses for your swap install. The ECM is located on the driver’s side of the vehicle.
At this point, the engine should be unfettered. If you are removing the engine and transmission as one unit, unbolt the transmission from its mount, support it with a jack, and remove the transmission crossmember. Disconnect the transmission wiring harness, shifter, driveshaft, and cooling lines. Unbolt the engine from the motor mounts on the frame and attach an engine hoist. Lift the engine (with the transmission attached) and slide it out of the chassis.
If you are taking just the engine, you need to support the front of the transmission from the ground first. Then use a flywheel turner to spin the flexplate until you reach each torque converter bolt and remove them all. At this point, you can unbolt the bellhousing and remove the engine separate from the transmission.
Because this is a drive-by-wire (DBW) vehicle, I removed the pedal and throttle actuator control (TAC) module and installed them in the swap project car. The TAC module is located on the firewall next to the power brake booster. Don’t forget these two items; you will need them if you plan to use the stock computer. If not, take them anyway, someone will want them.
With a little degreaser and elbow grease, your new LS engine will be ready for prime time in just a few minutes. Don’t forget to save the secondary sensors such as the mass airflow (MAF) sensor from the air inlet tube.
The engine is now ready for removal; only the radiator stands in the way. I did this last to keep the mess to a minimum.
The TAC module is a key component of the drive-by-wire (DBW) system, so you need it and the wiring harness that goes with it.
The pedal mounts to the firewall. A few turns of the 10-mm bolts frees it from its humble cage and readies it for your A-Body ride.
With the engine on a stand, you can begin to prep it for your swap.
