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[News Recap] ZR1 Engine “Confirmed”, UAW Strike Ends, Plant Temporarily Shuts Down

What engine is the ZR1 said to have now? As the UAW strike ends, what is causing the Assembly Plant to shut down?

Bowling Green Assembly Plant/Image Credit: Corvette Blogger

I’m on all the notable Corvette forums and social media pages all day every day, and I’ve done the legwork for you. Here are some compelling stories from the Corvette community.

1) GM Parts Catalog Leak Appears to Confirm ZR1 Engine

I put confirmed in quotes and wrote appears because at this point I still feel we won’t know for sure until the official reveal. As several screenshots from an internal GM Parts catalog began circulating around the net, some in our community are speculating that a lot of these leaks and “intel” from higher-ups at GM are a controlled effort to throw us reporters off the scent.

First, let’s look at the catalog leak, and then summarize what it tells us.

Abbreviations Decoded:

  • YR: ZR1
  • DI: Direct Injection
  • VVT: Variable Valve Timing
  • AFM: Active Fuel Management
  • DOHC: Dual Overhead Camshaft
  • M1K: ZR1-specific DCT code, suggesting an upgrade over the Z06 transmission

The Key Takeaway:

According to this latest leak, the 2025 ZR1 will have a DOHC 5.5L Twin-Turbo LT7 with DI, VVT, and AFM. Most outlets are reporting that the LT7 will have a cross-plane crank (CPC), versus the flat-plane crank (FPC) LT6 in the Z06. The CPC lowers the RPM range and offers greater reliability with a reduction of the FPC vibrations (while being able to add VVT and AFM technology).

Summary of ZR1 powerplant theories:

  • LT7 Twin-Turbo based on the flat-plane crank 5.5L LT6 out of the C8 Z06
  • 670hp LT6 in concert with the E-Ray’s 160hp 1.9 kWh electric motor on the front wheels
  • LT6-based Twin-Turbo with TWO electric motors
  • 6.2L cross-plane crank V8 (most likely with twin turbos)
  • AND NOW, a 5.5L cross-plane crank Twin-Turbo LT7 with VVT and AFM

Additional Source

2) UAW and GM Reach Tentative Agreement on New Contract

Multiple outlets are reporting that on Monday the UAW and GM reached a tentative agreement on a new contract. But, there is still room for something to go wrong, as the deal will need to be approved by local UAW leaders and then ratified by a simple majority of the 46,000 union-represented workers at General Motors. After the UAW reached agreements with Ford last week and Stellantis Saturday afternoon, the pressure was on GM to get a deal done. On Saturday evening, the UAW turned up the heat on GM by announcing that 3,900 workers would be walking off the job at GM’s TN Spring Hill facility.

Early reports indicate the framework of the agreement is similar to the deal the UAW worked out with Ford, with union members getting an initial 11% raise (which would go to 25% as the contract matures). It also reinstates cost-of-living adjustments, allows workers to reach the top wages in three years instead of eight, and protects workers’ right to strike over plant closures.

If you want a review of the tumultuous 6 weeks that led up to this agreement, CorvSport published a concise summary here.

3) Corvette Assembly Plant Stumbles and Shuts Down Temporarily

This story broke yesterday on MidEngineCorvetteForum and is still developing, but it appears a parts shortage from GM’s Bedford, Indiana plant has caused the Bowling Green Assembly Plant to shut down. So far, reporting indicates the stoppage was limited to the 2nd shift on 10/31 and the first shift on 11/01.

What exactly is the problem?

According to multiple members at the MidEngine forum, the source of the temporary parts supply issue is a shortage of aluminum castings from the Bedford plant.

Forum member meyerweb asked the million-dollar question and as soon as CorvSport gets an answer we will update you in our weekly recap.

I wonder what the root cause of this is. The Bedford plant has been making castings for the entire production run, and it’s only very recently that supply seems to be an issue. Is it a labor shortage, a shortage of raw materials, equipment malfunction, or…..?

I hope you have found this short but concise recap informative. We have the fastest-growing Corvette community on our Facebook page, with over 159,000 followers (40,000 since January!). Come join other hardcore enthusiasts and say hello, Douglas B.