The LS and LT-based engines are some of the hottest swap fodder in the automotive world right now. Thanks to Chevrolet Performance, that swap has gotten a lot easier with their Connect & Cruise engine and transmission packages.
The new LS and LT engines can fit into a variety of vintage chassis', so long as you consider idiosyncrasies of both the engine and chassis being used. Who wouldn't enjoy having up to 650 driveable horsepower with a GM warranty?
There are two things that any enthusiast worth their weight in hand degreaser will enjoy – performance, and choices of performance. There’s no doubting that today’s engines (which thankfully flow over into the General’s crate engine offerings) bring a lot of performance to the table. When base-model cars are churning out more than 400 NET horsepower, it’s definitely a good time to be into cars. And, thanks to Chevrolet Performance’s broad spectrum of crate engines, of which many are available as a Connect & Cruise packages, installing one of those high-powered V8s into your vintage ride has never been easier.
Connect & Cruise brings all the necessary components to get your engine running. All sensors, and ECM and TCM are included, along with the DBW throttle pedal assembly.
Let’s face it, folks have been swapping first and second-gen small-blocks into everything from street rods to small aircraft. Many of these people have done this swap so often that they’ve gotten all the necessary part numbers permanently etched in their gray matter. The small-block Chevy engine has been the go-to replacement performance engine ever since it dethroned the famous flathead Ford engine way back when, well, when folks were still running flatheads!
Earlier model cars both young and old can benefit from a Gen-III through Gen-V engine swap.
Even when port fuel injection came on the scene with L98s and LT1s, enthusiasts warmed up to these hot little engines, and many found new homes between older frame rails. Then, in 1997, the “small-block” Chevy engine changed forever, and many folks felt that the gate had closed on swap-worthy donors for earlier cars. Since then, history has proven that nothing could be further from the truth.
Enthusiasts can choose between both manual and automatic transmissions. The 4L65E (left) can handle up to 430 lb./ft. of torque. The Tremec T-56 Magnum manual box is beefy enough to hold 700 lb./ft., while the much larger 8L90E 8-speed automatic transmission (right) can handle up to 664 lb./ft. of torque
What started out as the LS1, has grown into a broad offering through GM that not only includes varying levels of performance, but also brings levels of performance that were only once dreamed of by many enthusiasts. The current platform of V8 engines has proven its affinity to upgrades, and the aftermarket has flourished to help fill the need for more power. Even Chevy has stepped up to the performance plate with supercharged versions of the latest generation of small-block.
More people are looking for the Connect & Cruise offerings… – Curt Collins, Chevrolet Performance
Curt Collins, manager for Chevrolet Performance, describes the current trend in crate engines for us, “LT sales (LT1, LT4, and the LT376/535) continue to grow since their introduction over the last several years. However, the LS sales also continue to grow as this line is now 20 years old, having been introduced in the 1997 Corvette with the LS1.” He goes on to explain, “More people are looking for the Connect & Cruise offerings, where our powertrain engineers have already selected the best transmission to pair with our engine.”
“It does not matter whether enthusiasts choose to use a small-block, big-block, LS or LT engine. With Connect & Cruise, they also get all the right hardware and calibration to support their build.”
The offset water pump and lack of P/S pump on the LT engines (left) can require new accessory-drive systems. Likewise, the down-low A/C compressor on LS engines can also hinder fitment with frame rails and suspension components. The aftermarket has solutions for both engines.
Today’s cars are packaging marvels, with every square foot of space accounted for and engineered accordingly. The design of the engine was a strong consideration when designing the car, making sure everything fit. But all bets are off when you transplant them into earlier-model vehicles. Thankfully, the aftermarket understands the need for things like air conditioning and power steering, so many issues that once troubled early adopters of these engines has now been addressed, and the solutions most likely have part numbers.
What You Get
What about many of the things that are inherent to the latest generation of LS/LT engines? Characteristics like the number of teeth for the camshaft and crankshaft sensors, and even the number of bolts that hold the flywheel in place can be specific to particular engines. Thankfully, Chevrolet Performance has taken the guesswork out of assembling a reliable drivetrain, including everything that the enthusiast needs to successfully infuse their ride with the newest powertrain on the planet.
Direct injection helps Gen-V engines balance both horsepower and fuel mileage. The bell housing bolt nearest the high pressure fuel pump at the rear of the engine has been moved slightly for clearance.
When we say everything, we mean everything. Sure, you get the engine, as well as your choice of transmission, which for most can include both automatic and manual versions. Depending on which engine you choose, your choices can range from the reliable 4L65E, 4L70E, 4L75E, and 4L85E four-speed automatics, or the stout Tremec Magnum T56 six-speed manual row-box. For those going with the newest versions of power, the 8L90E eight-speed automatic even becomes an option.
Both Chevrolet and the aftermarket have helped make LS and LT swaps manageable. Various engine and transmission mounts help make it fit, while Chevrolet's E-Rod package helps keep it legal.
The “E” after each of these transmissions denotes that they are electronically controlled transmissions, and the Connect & Cruise packages take this into account by supplying the necessary controller to make the shifting both smooth and carefree. The Connect & Cruise package also comes with the necessary ECU to get the engine up and running, and also features other necessities like the electronic throttle pedal assembly needed to control the drive-by-wire throttle bodies on each of these engines.
Both LS and LT engines were built with either wet (left) or dry (center) sump oil pans. Also note the LT4 dry-sump pan (center) has an additional oil cooler that may interfere with frame cross members or steering. The aftermarket offers various oil pans (right) to fit into many vintage vehicles.
A wire harness, fuse box, oxygen sensors, and mass air flow sensor (MAF) are also included in the Connect & Cruise package. For those who live in an area with stringent emissions-compliance regulations, Chevrolet also has you covered with their CARB-certified E-Rod offerings. All E-ROD systems include emissions equipment including catalytic converters and a fuel tank evaporative emissions canister, along with an engine control module calibrated for a balance of performance and efficiency.
Also keep in mind that if you decide to use a dry-sump oil system, you will need to find room for the oil canister and the rest of the necessary components.
That performance and efficiency is carried forward, thanks to the increasing technology that is available through the latest generation of small-block. While the SBC has enjoyed the fuel-sipping tendencies of EFI since the early ’80s, the latest LT version has integrated that technology with Direct Injection and Variable Valve Timing. The result is unprecedented power, torque, and fuel mileage.
What You Don’t Get
One thing that isn’t available in the Connect & Cruise package is the cylinder deactivation (Active Fuel Management). Per Chevrolet Performance’s install guide, “This system requires many inputs (weight of vehicle, tire size, final drive ratio, etc.) to work properly. Due to these unknown parameters, as well as the need to tune the engine mounts and exhaust system for operation in both V8 and V4 modes, the Chevrolet Performance engine control kit disables this feature. The engine has not been changed, so cylinder deactivation hardware is still present.”
LS vs. LT
The new LT1 and LT4 engines bring some new technology to the table, but what differences are there when installing one?
• Modulation capable fuel pump (72psi at 45 gph)
• Separate controller for PWM fuel pump
• Offset water pump may cause clearance issues
• No power steering pump
• Different numbered flywheel bolts
• Bell housings are the same, save for one bolt hole moved due to high-pressure fuel pump.
As mentioned earlier, depending on the crate engine you choose, you may have to swap out the accessory drive on the front of the engine not only for fitment concerns, but also to add power steering capability since all vehicles powered by Gen-V small-blocks now utilize electric power steering and Gen-V engines do not have factory power steering pump mounts.
The aftermarket has several solutions ranging from accessory drives that relocate the water pump and A/C compressor, while also providing mounting bosses for a power steering pump. The aftermarket also offers fluid-free, electric power-steering assemblies that can be added to the vehicle’s steering column to assist turning, if you would prefer to go that route.
The LS-based engines used some sort of external fuel pressure regulator. All Gen-V engines are designed to feed from a pulse-width-modulated, in-tank fuel pump (right) that regulates fuel pressure to the necessary 72 psi. Connect & Cruise packages have the necessary PWM controller as part of the kit.
Also, mating drivetrain and chassis has to be left to the end-user since a one-size-fits-all doesn’t work well in a custom-made environment. Again, the aftermarket has stepped up to the plate with sturdy engine and transmission mounts that are adjustable to allow for variances in engine placement while providing mounting points to the most common chassis mounting designs.
Not Necessarily Factory
While no one would argue that today’s engines are producing some substantial performance numbers straight from the dealer’s showrooms, it’s evident there are enthusiasts within the ranks of General Motors who understand that enthusiasts want even more performance. They took a production, 430 hp LS3 engine and plopped in the LS Hot Cam to give enthusiasts 495 horsepower and 473 lb./ft. of torque in the 376/480 package. And, for those who still want more, their ASA-cammed 376/525 package is sure to please. Both are available as crate engines and Connect & Cruise packages from your Chevrolet dealer, via the parts counter, not the showroom.
Fitting and mating an exhaust to the elongated flanges of the LT1 and LT4 engines may be problematic. The sixth-generation Camaro exhaust has a much more typical exhaust flange and exits more rearward for additional clearance.
Many other high-horsepowered options were available through dealer’s showrooms. Like the now-famous 505 hp LS7 that took the world by storm in the C6 Z06 Corvette and the supercharged, 556 hp LSA found in the Cadillac CTS-V Series and the Chevy Camaro ZL1. From there, the numbers keep going up, like the 638 hp LS9 from the ZR-1 Corvette and the new 650 hp LT4 found in the current Z06 Corvette. Of course, all Chevrolet crate engines and transmissions are covered with a GM warranty, which is as close as your local GM dealer.
The latest generations of Chevrolet crate engines can bring a lot of performance to vintage rides, and can look right at home while doing it!
Whether you decide to go with any of the LS or LT-based engines, the jump to latest-gen technology has never been easier. As stated, it’s still not necessarily a drop-in upgrade, but with Chevrolet Performance’s Connect & Cruise packages and the assistance of the aftermarket, it can be done, and the additional power is well worth the effort.