The 2023 Chevrolet Corvette Z06 is home to the most powerful naturally aspirated V8 ever in a production vehicle. The 5.5-liter V8 produces 670 horsepower and 460 pound-feet of torque, and it will scream like an Italian exotic thanks to its flat crankshaft.
After working on it since 2014 and knowing how special this engine is, GM Engineers sweated and timed into this spent an afternoon going into detail about everything someone might want to know. From there, we give you the 9 most exciting things about the LT6 in the upcoming Z06.
Learn about racing cars (and Ferrari 458)
Yes, Chevy initially thought a strange plane-rotating engine was about to be born through its C8 R race car a long time ago. Since then, we’ve known that the 5.5-liter V8 in the aforementioned race car is very similar to the production Z06 engine – they share the cylinder block, head, valve system and fuel system. We all know the saying, “Win on Sunday, sell on Monday.” GM has taken this mantra quite literally, as the racing program has helped engineers develop street car engines to a certain extent. Perhaps more interestingly, the Z06 street car engineers also helped the team improve their Gemini version.
The main benefit to the carmaker team is that all the authentic data they can gather from the race team running the engine in competition over thousands upon thousands of miles is pushed to the limit. Engineers have data on wear surface, thermal management, operating parameters and more. Racing and production teams sometimes even share parts, swapping out when one wants to test something new the other has come up with. Even to this day, the two groups are still working together to perfect what will eventually lead to a buyer’s driveway.
For Ferrari 458 learning, you’ll be interested to learn that GM bought a wrecked 458 from Europe for $25,000 years ago, completely tearing it up to find out what makes Ferrari plane plane spins very well, then applies that knowledge to its own V8. So yeah, there’s definitely some Italian flair hidden inside this American supercar. A modern 458, anyone?
Cooling and oiling
If you call back C7 Z06Chevy ran into all sorts of cooling problems while that car was on the track. Engineers were determined to keep that from happening with the C8 Z06, as its cooling seems to be over-engineered to the max. Total cooling capacity is increased by 50% compared to the standard Stingray with the Z51 package, and it has a total of 5 heatsinks boosted by more powerful fans. The front bumper even has a removable aero panel that increases the opening of the front grille by 75% – Chevy recommends removing this panel for track use. The real good thing is that Chevy was able to add this entire cooling system without sacrificing storage anywhere in the car, including the front trunk.
Monitoring mice will be pleased to know that the Z06 has a new and custom designed dry oil suction system. It has an engine mounted plastic oil tank and this system ultimately provides 85% more cooling than the system in the C7 Z06. It has six pick-up pumps, a bottom-mounted oil cooler and is designed for excellent garbage collection even at the high side levels the Z06 can tow. Chevy claims the Z06 with the Z07 package can pull 1.22 g of lateral acceleration on the slide.
Mechanical valve system using high-tech materials
One particularly appealing aspect of the Z06 engine is that it uses a mechanical (non-hydraulic) valve system that GM claims will never require maintenance or adjustment over the life of the engine. It is factory hit and the clearance is measured three times over the life of the engine, but it will never need servicing. GM says this is made possible through the use of today’s modern materials. For example, the finger followers are highly polished with a diamond-like carbon finish and are made of hardened steel. The exhaust valves are nitrided steel valves containing sodium in the hollow cavity, and the intake valves are made of titanium. Everything is designed to withstand extreme wear. Even during GM’s high mileage validation, engineers say that everything is still within spec.
All of this highlights that while the Z06’s engine may be an odd design, GM says it won’t require the odd level of maintenance and short maintenance intervals. It had to go through all of the same GM validation tests. Ray passing, so expect it to perform the same in extreme conditions.
Of course, it’s a flat hand crank design
Finally, this reason Escort ship will scream like a weird Italian car lying down on its flat (not flat) crankshaft design. This gives you a different firing order and a balanced airflow and exhaust. Chevy says the crankshaft is made of forged steel and it’s 33% lighter than the crankshaft in Stingray’s LT2 engine.
Each engine is hand-built by a single technician
In addition, each Z06 engine has a plaque signed by a single technician who put it together. Chevy says it takes about 3 hours to build a single engine, and that they will all be assembled at the Performance Manufacturing Center in Bowling Green, KY.
Once built, each LT6 will be shipped to a local dyno facility, where it is made to a 20-minute process to run the engine at full load and high engine speed. Similar to Standard Corvette, the break-in interval is 500 miles long. Torque in first and second gears is automatically limited during this time.
Air conditioning systems are monitored for evaluation
GM’s goal with the Z06’s air-conditioning system is to allow proper cabin cooling during track use with ambient temperatures of 100 degrees Fahrenheit. If that’s not the goal, the American supercar aim, we don’t know what that is. To achieve that goal, Chevy had to design a new air conditioning system that was different from the stingray C8. To run the compressor when the engine was humming at 8,600 rpm, Chevy used a lower pulley ratio. However, this slowed the pulley down too much at low speed and at idle, so the team had to increase the size of the A/C compressor to compensate for the change. GM suggests that the air conditioning on the Z06 is actually slightly better than the current Stingray because of this change. Plus, you can run well and stay cool on the track in extreme conditions.
The exhaust system’s adjustable rack is the first GM
The Z06’s emissions are an important factor in vehicle enjoyment and GM has not overlooked its importance. Instead of a normal adjustable exhaust where the valve has two settings, open (loud) or closed (quiet), the valve in the exhaust system is highly adjustable through multiple settings. The valves – found in the center line – are controlled by the engine ECU uses patented software and it allows GM to adapt them in 2 gradual increase. The outside pipes are Corvette “low flow” piping and have no valves. In total, GM allows three different valve presets selectable by driving mode: Tour, Sport, and Track. As expected, the Track is the noisiest setting, although GM says it’s loud enough that you might have to turn around on tracks with strict noise regulations.
As for emissions performance, GM says its new exhaust architecture reduces back pressure by 21% compared to C7 Z06, and the silencer itself is 20 pounds lighter than the C8 Stingray’s silencer. Like you’ve seen in the photos, it has a center exit which GM says is a last-minute change to dramatically improve the sound.
54 Gemini rockets can be found on every LT6 . engine
Chevy’s internal name for the LT6 project is Gemini, in reference to NASA’s Gemini Space Program. The team considers this to be an image of an engine, so they wanted to include it in some spatial imprint. If you look hard enough, you should be able to find a total of 54 Gemini rockets per engine. Have fun hunting!
Chevy still calls it the Little Block
This is so strange. The only thing LT6 has in common with tradition Chevy Small Block V8 is the distance between its 4.4-inch barrel centreline. In addition, it is built and designed by the same team responsible for the traditional Small Block V8. Besides, this engine is a completely new, clean design. Visually, GM engineers say it’s a “Gemini Cube”. In fact, there is almost nothing in common between this cutting-edge DOHC engine design and the old push-pull V8 found in the regular version. Corvette Stingray. So go ahead, check out the comments and let us know what you think on whether this should be called the “Small Block V8”.