Lingenfelter's New C8 Motor Reminds Us There's No Substitute for a 427 in a Corvette

Yahoo

26-03-2025

Some pairings are just an inherent part of the American experience. Burgers and fries, arms and the right to bear them, and Chevrolet Corvettes with 427-cubic-inch V-8s are about as red, white and blue as they come.
While Chevrolet has shied away from the large-displacement recipe for the C8-generation Corvette, the team at Lingenfelter Performance Engineering is ready to deliver on that almost-constitutional right. Not only has the company developed a 7.0-liter monster for the C8, but it's also getting ready to drop a new twin-turbocharged variant — with ZR1-rivaling levels of power.
A little history first. The original 427-cubic-inch big block V-8 arrived on Corvette order sheets for the first time in 1966. Customers could initially choose between a 390-hp variant known as L36, or a rowdier L72 with 425 hp on tap. The next year saw the addition of the "Tri-Power" L71 variant, which upped performance to 435 hp. And few engines are quite as legendary as the L88 and all-aluminum ZL-1 variants that shortly followed, cementing the 7.0-liter engine as an undisputed Corvette icon.
GM would return to the 427 recipe for the C6 Z06 and 427 Convertible models with the small-block-based LS7. Many consider that high-revving V-8 to be a high point of modern Corvette powertrains — so it's no surprise that LPE mirrored that engine's famed bore and stroke figures for this new project.
'There's just something about Corvette and 427 that just kind of has to go together,' says LPE owner Ken Lingenfelter. 'And, you know, I think that's part of the inspiration. I think part of it is just, we're always trying to get as far as we can go, take it to the limit."
The brand approached the 427-cubic-inch engine project with the care and attention to detail that's long characterized its builds. "We do a lot of testing, and we have to make sure. We can't send a car out of here and have people looking at lights popping up on a dashboard. I mean, it's got to be a solid project," he says. "We're 52 years old this year. So you know, we want to make sure that we're sticking with the right things, and going down the right paths. But, I mean, as soon as we let the word out we were doing 427, it was like, 'Oh yeah! Attaboy!' And that's what we want to hear.''It's the iconic GM way of doing it, you know?' says Brandon Baker, vice-president of sales and marketing at LPE. 'To our knowledge and from our testing, GM didn't just make a 427 out of those numbers randomly. It was very strategic, and the 4.125-inch bore and the 4.00-inch stroke definitely came for a reason. It wasn't them just throwing those numbers on a table."
"So we definitely [wanted] to stick with that. We didn't want to cheat the system and run a little bit shorter crank, and just run a larger piston... we could have definitely taken the easy way out and had it out probably five, six, or seven months before we did. But we tend not to take the easy way out here. Sometimes it holds us back a little bit and puts us behind a few other places out there, but we just like doing our homework.'
Adapting the Corvette Stingray's stock 6.2-liter LT2 V-8 wasn't quite as simple as swapping out the crank. LPE wanted to keep the factory oil pan in place, as customers weren't interested in spending several thousand dollars on a part so 'inconsequential" to big power. The C8 features a dry sump oiling setup, to assist with packaging and track performance, but that means the factory pan is already quite tight. LPE teamed up with the folks at Callies to custom develop a custom weighted stroker crank that wouldn't disrupt the factory pickup and scavenging locations. The camshaft has also been specially tuned for use with a dual-clutch transmission, ensuring smooth pickup and power delivery.
The vast majority of components can be shared between LT1 and LT2-based builds, but the engines do have some fundamental differences that require a rethink. That's particularly true in the valley of the LT2s, which are substantially changed versus the LT1. Eliminating the factory Displacement on Demand system played a huge role in sorting out the breathing issues presented by the reworked valley design, however, and the DoD delete kit has become a popular standalone part for LPE as a result.
'The LS7 blocks were the absolute best for those bay-to-bay breathing, crankcase, windage — all of that stuff they did really well,' says Baker. 'We lost that on the LT1, and we lost it even more on the LT2 block. So the LT2 block isn't really designed for big, high-horsepower applications, or big cubic-inch deals. That's where we ran into problems pretty early on."
"But you do all of that testing and do all of the stuff in house to find those limitations and those areas that need improvement,' he adds.
Lingenfelter sources LT2 block 'cores' from customer cars, with each undergoing a CNC blueprinting and sleeving process. From there, the engines receive all-new pistons from Mahle, as well as ported cylinder heads developed in-house. Naturally-aspirated builds retain the factory fuel system, with tuning centered around 91 octane fuel; LPE says they've had more success with the mid-grade octane than 93, owing largely to the car's direct injection layout. Tuning for 91 also provides better flexibility for customers out West, where punchy fuel is less available.
The end result is no less impressive for using 91, however. LPE claims more than 700 hp at 6700 rpm and 600+ lb-ft at 4800 rpm. (In stock form, the LT2 engine is good for 490 hp and 465 lb-ft of torque.) That sort of output does require a clutch upgrade from Dodson in New Zealand, who have been working with LPE as development partners since last November.
For those who need even more power, LPE is also developing a twin-turbocharger package to bolster the 427, which will see outputs well in excess of 1100 wheel horsepower when drinking E85. A package with closer to 700 horsepower will also be available on the 'lower' end of the spectrum. The development mule has already been running around for a few thousand miles, but LPE is waiting for warmer weather in Michigan for its final tests.
The package is designed to look nearly factory-spec, with the final layout set to mirror the turbo placement found on the C8 Corvette ZR1's LT7. It only takes around 15 pounds of boost for LPE to extract all of that extra performance, though an upgraded fuel system is also required for the boosted application. Full details on the turbocharged package pricing are slated to arrive soon.
The 427 can also go hybrid. Thanks to the way GM designed the Corvette E-Ray's electric front axle, that model offers another pathway for more performance out of the 427 package. The electrified front axle brings an additional 160 hp and 125 lb-ft of torque, and is seamlessly integrated with the higher-power motor out back. The E-Ray also benefits from Chevrolet's magnetorheological dampers and carbon ceramic brakes, making it a great launching point for this kind of build. (Lingenfelter is no stranger to the platform either, having built the first supercharged E-Rays on the market.)
As you can imagine, packing a 7.0-liter V-8 into a C8 isn't exactly a cheap proposition. LPE says that the naturally-aspirated packages start at $29,950, but most customers end up spending a bit more. Lingenfelter recommends pairing the setup with the brand's intake manifold, throttle body, and exhaust packages for better breathing; opting to skip these components will result in a slight drop in performance, so expect to spend closer to $35,000 for those claimed horsepower figures.
That price does include all of the installation work, however — which is sped along by the supply of core motors already in stock. LPE is working with a wait list of a few months, though, so don't hesitate to pick up the phone if this all sounds good to you.
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