How to Make the C6 Corvette Z06 LS7 Engine Bulletproof
Known for oil system issues and not responding well to mods, the C6 Corvette Z06 LS7 isn’t too hard to beef up.
By now, pretty much every Corvette fan out there is aware of the many issues befalling the LS7 powerplant present in early C6 Corvette Z06 models, which have led to some complete failures in certain instances. While there’s a lot of information – and misinformation – on this topic floating around the internet, back in September 2022, Lyle at C&S Corvettes was able to speak with Paul Kerner, the head Corvette tech at GM, who explained that modifying things like the air intake and exhaust can have catastrophic effects on earlier examples. Now, Lyle is back with a followup video with new information about the earlier LS7 powerplants that he acquired from another “high up” former GM employee who wished to remain anonymous this time around.
That person – who Lyle simply refers to as “Duntov” – notes that the dry sump oiling system used in early C6 Corvette Z06 models – ones produced between 2006 and 2008, specifically – is inherently flawed. This system was purportedly designed to work properly up to one full lateral g of cornering, which the car is certainly capable of. However, when folks began putting stickier tires on their Z06s and taking them to the track – exceeding one g in the process – the oiling system simply wasn’t capable of doing its job properly.
Somewhat shockingly, “Duntov” allegedly told Lyle that GM was well aware of this fact, as it “killed” a handful of motors during testing. But, ultimately, the automaker decided that the dry sump oiling system present in these early C6 Corvette Z06 models was good enough for what most owners would be using them for. Later on, during LS3 development, the automaker discovered that this engine’s wet sump system was capable of handling more than one g of cornering force, and in 2009, made changes to the LS7, too.
That change was simply adding an auxiliary tank to the LS7’s oiling system continuing two and a half quarts of additional oil that allowed the system to function properly at higher cornering forces. “Duntov” therefore recommends that owners of pre-2009 C6 Corvette Z06 models upgrade to this newer tank to prevent oil starvation during high g cornering driving sessions.
But as they say on infomercials, wait, there’s more…
Other LS7 DOs and DON’Ts For All Model Years
“Duntov” also noted that adding forced induction or nitrous to the LS7 is a bad idea, as its hypereutectic pistons – which are infused with silicon – don’t hold up well to such modifications and only make its piston slap issue worse. Of course, there is also a workaround for this problem, too – replacing those pistons with forged pieces such as those made by K-Tec, which are designed specifically for that purpose.
Aside from these tips, “Duntov” recommends pulling the valve covers and checking the rocker arms for valve wobble. In such cases where wobble is present, LS7 owners should either replace the valve guides (a cheaper, but temporary solution) or swap in a new set of heads from a brand like K-Tec (a pricy, but longer-term solution).
Either way, people shouldn’t fear the LS7 outright. You just need to respect and be proactive about what appear to be its inherent limitations.
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