Although this srory relates to the new small block in Trucks, thought might be of interest for the LS6 going in all 2027sGM appears focused on improving trust, and not just horsepower

by Chris Chilton

• GM is tightening engine quality controls ahead of next-generation truck launch.
• Some manufacturing is moving in-house for greater oversight and consistency.
• New V8 arrives after 6.2-liter recalls damaged confidence among truck buyers.

As the company prepares to launch the redesigned Chevrolet Silverado and GMC Sierra in 2027, it reportedly isn’t just developing a new V8 engine. It’s also taking steps to make sure buyers don’t spend the next decade wondering whether that engine is going to become the subject of another series of recalls.

According to a new GM Authority report, GM is introducing stricter quality controls for key components in its upcoming Gen 6 Small Block V8. As part of that push, some critical parts and manufacturing processes are reportedly being brought back under GM’s direct control, rather than being handled by outside suppliers. That might sound like a boring industry detail, but it could be one of the most important developments surrounding the next-generation trucks.

After all, this comes just a year after GM recalled nearly 600,000 trucks and SUVs equipped with the 6.2-liter V8. Investigators linked engine failures to manufacturing and quality issues involving internal components. The issue became one of the biggest black eyes for the company’s truck business in recent memory, and against that backdrop, the timing of these reported changes doesn’t feel accidental.

The new Silverado and Sierra are expected to replace today’s 5.3-liter and 6.2-liter V8s with fresh 5.7-liter and 6.6-liter Small Block engines. The 2027 Corvette‘s 6.7-liter, 535 hp (542 PS) version of this engine was revealed in March. GM has already committed enormous sums toward production, including an $888 million investment in its Tonawanda facility to support the next-generation V8 program, and the engines will also be built at two other plants, one of them in Canada.

Whether the new engine design and the decision to bring more production processes under direct control translates into bulletproof reliability remains to be seen. Engines earn their reputations on highways, job sites, and towing routes, and that takes time. But after the bruising few years GM’s V8s have endured lately, tighter oversight may be exactly what truck buyers want.

 

I think that GM is admitting that what the powertrain engineers said that outsourced mechanical quality is very hard to control.
I find it very telling that the 6.2 LT2 destined to be used in all the Stingrays came from a single source: Tonawanda. The 6.2's at the center of the problems all had either outside assembly points or outside suppliers for stuff that is made in house at Tonawanda. JMHO, the juice was for sure not worth the squeeze in the pursuit of saving money on engines for the masses!
I get it that by the numbers alone it probably sounded great, but I'm sure there was a reason (besides the # of engines that BG would need) that the corvette LT2 is only made at Tonawanda. That reason must have been quality control.
JMHO


Tom

 

Shades of LS7?

 

Yep, GM like many auto manufacturers stopped making most parts themselves many years ago and outsourced becoming assembly plants.

Actually the Tonawanda 6.2 V8 Liter problem engine issue is related to the Truck Engine. The big 600,000 recall of V8 Truck engines over several years production of the 850,000 Silverado/Sierra Trucks they make each year for the half who opt for V8s. BUT those truck engines used cast iron crankshafts where the Corvette LT2 uses a Forged Crack. To my knowledge GM has not defined what the issue with the cast iron crank was BUT one independent Group disassembled one that failed the GM "listen" test. See Pics below of that groups suggested a cause.

It does not appear that GM is having to replace the engines. They have a test that they perform, like on my friends GMC Denali. They run the engine at specific rpm and have a device that "listens" to the engine operating. That test can "define" if it needs to be replaced. In his case, apparently like most, it passed BUT they changed the engine oil from the specified higher mpg 0W-20 to the C8 Corvette Mobil Supercar 0W-40.

An independent group took a 6.2 Liter Truck engine that failed the GM "sound Test." They found the cast iron crank had a very lathe oil inlet chamfer. They commented and I found that excess chafer in racing engines can cause bearing issues do to cavitation. Is that the issue Don't Know and Don't Know IF GM has identified that or something else related to the cast iron crank.


PS:The Corvette LS6 is being assembled in Michigan where it had been years ago. My Guess that has more to do with perhaps capacity in Tonawanda (although that does not appear logical as ~30,000 corvette engines versus half the 850,000 trucks that opt for V8s or ~400,000 = 8% that is a small #.) May have more to do with GM negotiations with the UAW and the Michigan facility!

 

GM has forever tarnished their truck V8 reputation. Combine that with them being silent on the Z06 fuel recall. They could have advised on the parts schedule and many other little things that would have at least let people who had sold cars stuck at dealerships feel supported. I have a Z06 but would not look to GM for any other products. They managed to mess up the Corvette support so bad with the still lingering DCT issues, Z06 Oil leaks, and Z06 valve train issues that even these aren't very palatable or at least you must buy one knowing there is a lengthy problem history that you are likely to experience.

 

^^^^
Funny, just like Vette buyers GM has Truck Groupies!

• 2025 Silverado/Sierra sales = 944,927
• 2025 Ford F-150 sales = 828,832
• 1st Qtr 2006 Silverado/Sierra sales = 204,425
• 1st Qtr 2926 Ford F-150 sales = 159,901

With the New Small Block 2027 will be even better!

PS: BTW, they sold 25,825 Corvettes in 2025. Think anyone on the GM Board is worrying about Corvettes? We're lucky they took the engineering time and spent the money to make the Corvette LS6 Variant of the new truck engine for us!