Leaked CAD Images Showcase the new LT7 V-8 that Will Power the 2021 Chevy C8 Corvette Z06 – Here’s What We Think We Know
The LT7 V-8 is going to be a doozy!by Robert Moore, on
With the 2020 Chevy C8 Corvette set to debut in just a few days’ time, It’s not all that surprising that leaks and rumors are swirling the internet. The most recent leak\rumor places a new, twin-turbo V-8 – known for now as the LT7 – at the heart of the midengined Corvette. This is big news but, while there are leaked CAD images floating around the world’s digital playground, there is absolutely zero confirmation from Chevy. Be that as it may, we have some questions: When will we learn the truth about this alleged LT7? Will the Corvette’s LT7 be based on Cadillac’s Blackwing V-8? How much power will the LT7 make? What does it all mean?
The Recently Leaked LT7 for the C8 Corvette Isn’t the Base Engine
When the 2020 Chevy C8 Corvette Debuts on July 18th, we’ll be there to see it go down. We know that model will carry the Stingray name and, as the entry-level model, it will feature GM’s new, 6.2-liter, LT2 V-8 and should produce somewhere in the ballpark of 500 – 550 horsepower in base configuration.
This engine is expected to feature the typical LT overhead-valve, pushrod valvetrain (as opposed to an overhead camshaft arrangement), and that means it’s probably based on the same design as the current LT1, LT4, and LT5 engines with minor changes for reliability and power delivery as well as mounting since, you know, the C8 will have the engine behind the front seats.
Current Chevy and Cadillac LT Engines
The LT1 is currently known internally as a “Gen V, 6.2-liter, small block” which is, suffice it to say, a little weird as GM has only built three versions of the LT1 – Gen I was built from 1970-1972 while the other was offered from 1991-1997, both of which displaced 5.7-liters. The newest (technically third-generation) engine displaces 6.2-liters and can be found in the C7 Corvette Stingray, Corvette Grand Sport, and Chevy Camaro SS. In general terms, it generates 455 horsepower and around 460 pound-feet of torque in a standard configuration, so the 500-550 horsepower from the LT2 in the C8 will be a huge improvement for the Stingray name.
|Chevy LT1 V-8||Chevy LT4 V-8||Chevy LT5 V-8||Cadillac LTA V-8|
|Torque||460 lb-ft||630-650 lb-ft||715 lb-ft||373-410 lb-ft|
The current LT4 follows a similar timeline, but it wasn’t conceived until 1996 when it was offered as a 5.7-liter small block. That generation only lasted one year before being phased out. The current LT4, which was introduced in 2015, is also considered a “Gen V” engine and displaces 6.2-liters with a supercharger slapped on it for some extra grunt.
This engine delivers between 640 and 650 horsepower and around 640 pound-feet of torque depending on the application.
It can be found in the current C7 Corvette Z06, Camaro ZL1, and the Cadillac CTS-V.
The LT5 was just recently introduced with the new Chevy C7 Corvette ZR1, and it has remained exclusive to that model. It, too, is considered a fifth-gen engine and delivers a respectable 755 horsepower and 715 pound-feet of torque. Like the other LT engines, it features an overhead, pushrod-driven valvetrain, but it features a larger supercharger than that of the LT4 found in the C7 Corvette Z06. To help improve reliability under all that power, Chevy was forced to install a stronger crankshaft while a larger throttle body and larger fuel injection system were also needed. It’s possible that the C8 ZR1, if there will actually be one, will feature a revamped version of the LT5 or a beefed-up but currently unconfirmed LT7 paired with a hybrid drivetrain. If so, this will be the model that we’re expecting to deliver around 1,000 horsepower and fight it out the world’s finest exotics.
If rumors of this alleged LT7 turn out to be true, then it will be the successor to the LT4, but there’s more to the story then that.
GM’s Rumored LT7 Engine Could Be Based on Cadillac’s Blackwing V-8
GM has been pretty clear that Cadillac’s Blackwing V-8 that’s found in the Cadillac CT6-V would be exclusive to the Cadillac brand.
That’s a shame because it would have made bringing the C8 to the market much easier – at least in Stingray form, anyway. This engine, in the CT6-V, delivers a cool 550 horsepower and 627 pound-feet of torque, more than enough and on par with what we’re expecting from the LT2 that should be showcased on July 18th when the new C8 Corvette Stingray makes its long-awaited debut. That doesn’t mean, however, that Chevy isn’t using the Blackwing (known internally as LTA) as a basis to create the LT7.
There are a couple of different ways this could go. First, the LT7 could use the LTA’s engine block with GM installing tougher components to accommodate the higher power output. The pistons, connecting roads, and the crank would all be stronger. The heads would be similar, but they would be altered as well. The other possibility is that the LT7 will simply be based on the LTA’s design but will be largely different. That wouldn’t make sense as we don’t see GM spending a ton of money to develop an engine that’s exclusive to low-selling models like the Cadillac V-lineup and not use at least part of the R&D elsewhere, but it’s still a possibility. The one thing we do know based on the leaked CAD images is that the LT7 won’t feature a “hot vee” in which the turbos are located in between the cylinder heads. Instead, these will be mounted down below the headers in a more typical fashion.
|Cadillac CT6-V Blackwing V-8|
|Suspension||Magnetic Ride Control|
|Brakes||Brembo V-Series Specific|
|0-60 mph||3.5 Seconds (est)|
|Top Speed||192 mph (est)|
The LT7 Will Usher in a New Breed of LT-Engines for the Chevy Brand
The 4.2-liter, LTA, V-8 found in Cadillac V-series models is a DOHC engine, which means that the valvetrain doesn’t rely on pushrods for mechanical movement. Instead, each cylinder head has its own camshaft as opposed to the block-mounted camshaft found on the LT1, LT4, and LT5 engines.
Since the current crop of Chevy LT engines are all of the OHV configuration, the DOHC LT7 will be a big change.
It could provide more flexibility in terms of valve and lift timing, and it allows the engine to breathe better because there aren’t as many valvetrain components – with DOHC engines, there is no need for pushrods, and the overall design of the valvetrain itself is different. All told, DOHC engines are typically more efficient and more powerful than OHV engines, but there are some drawbacks.
DOHC engines are generally a little more complicated, and it could end up being costly for those that end up owning a C8 Corvette. With DOHC engines, valvetrain timing is way more complicated. Moving from an OHV to DOHC design means you also lose the all-too-reliable timing chain in place of a timing belt. These timing belts are more susceptible to stretching, breaking, and general wear, and therefore, must be inspected and replaced at regular intervals. We haven’t seen the C8’s overall design yet, but we’re guessing a major timing overhaul at 100,000 miles (the typical life of a timing belt) isn’t going to be an easy job. Hell, that job isn’t easy on FWD Hondas or Toyotas with relatively open engine bays, so something tells us this is going to be a costly piece of maintenance on the C8 Corvette. The other big downfall is the fact that DHOC engines are typically larger than their OHV counterparts. This can mean increased weight and difficult repairs, especially in a midengined car.
DOHC engines aren’t a new subject when it comes to performance cars, and if you look around, you’ll find a lot of them. Ford’s EcoBoost V-6 in the Ford Mustang features the same design, as does Ford’s 5.2-liter, supercharged, V-8, and the 5.0-liter Boss 302 V-8. BMW S65 V-8 can be added to that list, as can the Infiniti VR30 and Merc’s Inline-Six. Even the 3.8-liter DOHC in the 2019 Nissan GT-R pumps out 565 horsepower, which is something not all pushrod V-8s can accomplish. It’s just something that Chevy guys will have to get used to in performance cars because something tells us that the LT7 will end up in other performance models as well.
How Much Power Does Chevy’s LT7 Make?
How much power Chevy’s new LT7 will make is a big mystery and, since we probably won’t hear any official word about it until sometime in late 2020 at the earliest, GM has a lot of time on its hands to perfect the engine.
Since it’s set to be a DOHC engine, it’ll be widely tunable, so the possibilities are endless.
The LT7 is expected to be found behind the seats of the C8 Corvette Z06 and, most likely, the C8 Corvette ZR1. With the entry-level C8 Strinray expected to offer anywhere between 500 and 550 horsepower, the LT7 needs to offer up a lot more than that. It will be plonked in the Z06 and needs to deliver more than the 650 horsepower provided by the C7 Z06. So expect the LT7 to offer around 675 horsepower on the low side of things and as much as 800 -850 horsepower on the high side. But wait, it gets better.
|2020 Chevy C8 Corvette Stingray||2021 Chevy C8 Corvette Z06||2020 Chevy C8 Corvette ZR1|
Rumors have said that the new C8 Corvette will be offered as a hybrid as well. This will probably happen for the range-topping model, which will likely carry the ZR1 badge. That means, a high-output LT7 with, say, 750 or 800 horsepower could be paired with a couple of electric motors and boost output to as high as 1,000 horsepower, if not more. That, my friends, is how Chevy will finally be able to take on Ferrari and Lamborghini, and it will do it well.
When Will We Know More About the new Chevy LT7 Engine?
Right now, details about the LT7 engine are sparse at best. With it set to call the Corvette Z06 and ZR1 home, don’t expect to hear anything about it on July 18th when the new C8 Corvette makes its debut. C
hevy will likely sell the new C8 Stingray and its LT2 engine solo for anywhere between 12 and 16 months before introducing a higher-performance model.
That means the most likely window of debut is some time at the end of 2020 or, more likely, sometime in the first half of 2021 – most likely at the Chicago or Detroit Auto Shows. Along with the new LT7, Chevy will probably showcase the Z06 and continue working on the ZR1 for another year or two before it’s finally shown off.
The debut of the first production-ready, midengined, C8 Corvette is a huge milestone in the history of not only the Corvette itself but for the Chevy brand as a whole. It will likely reshape the “American supercar” market and will likely force Ford to rethink what it’s doing with the Ford GT, as I honestly don’t believe the GT as we know it will be able to keep up with the new mid-engined C8. There’s too much desire, anticipation, and heritage surrounding the Corvette and its new midengined roots for the Ford GT to remain relevant as it is now. Furthermore, if there’s really a 1000-horsepower C8 in the works, then some of the finest cars in the world could end up being bested by something with a bowtie emblem, and it’s going to make the next decade a very interesting one as far as supercars are concerned. I honestly can’t wait to see what Chevy has cooked up and will cook up over the next 5-6 years. This is either going to be a huge move or a complete disaster. I’m really not sure which yet, as Chevy needs to do the C8 right, but with everything we’ve seen and heard so far, it doesn’t look like the C8 is going to disappoint – not as a corvette, not as a mid-engined car, and not as a supercar fighter that could deal a direct blow to Ferrari and Lamborghini, among others.
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Source: GM Authority