The new LT6 V8 engine is a thrilling new addition to the engines from General Motors, and of course, the road to making it production-ready wasn’t easy. It’s rare for large automakers to talk about the failures they encountered during the development of new vehicles or engines. But the 2023 C8 Corvette Z06 isn’t just any car, and the LT6 isn’t just any engine.
General Motors sent Small Block Chief Engineer Jordan Lee to the annual NCM Bash so he could tell us all about the Gemini Project. Included in his talk was a story about the vibrations in the early prototype motors. Utilizing a flat-plane crank allowed the engineers to maximize volumetric efficiency for greater power, giving the engine the ability to redline at 8,600 RPM. That high rev range also means this V8 engine will reach high octaves that no Corvette has reached before.
Image via GM.
Overcoming Early LT6 Engine Issues
There is a known downside to the flat-plane crank: “it shakes like a paint shaker,” as stated by the chief engineer. Ford’s own flat-plane 5.2L Voodoo V8 exclusively found in the Mustang Shelby GT350 had an issue where the shaking would cause the oil filter to spin off the engine. Yikes. The engineers thought that was “pretty hilarious” and doubted they would ever make that kind of mistake until, during testing, the oil filter spun off the engine.
Lee told the crowd during his presentation that while working with the first development engines, he recalls the number 2 engine testing on the dyno lab when the engine suddenly lost oil pressure and failed. After looking into the test cell, they saw that the LT6 V8 engine’s oil filter was on the ground and figured someone had forgotten to tighten it. After setting up a camera to watch the filter on another engine, the Corvette Z06 team discovered that the filter started to spin off the motor once it got up to speed. Double yikes.
The engineers then realized that it wouldn’t be an easy task and spent five years working on all the vibrations and other issues. According to Corvette Blogger, the C8 Corvette Z06 team even threaded fuel injector connectors were being shaken apart, causing engine codes and other coil issues. But they managed to sort out all of the issues with time, so Z06 owners won’t have to face these problems.