If you’re a fan of the Gen-III/IV small-block Chevy engines, and have ever needed to order a damper for one, you know just how many possible combinations and part numbers there are to choose from. Part of the slew of part numbers is differences in engine configurations and part of that is because of all the optional choices and features. Usually, a quick call to ATI Performance Products’ tech line or a visit to their website will get you sorted out, but it can still be initially overwhelming. Enter GM’s latest engine platform: the 6.6-liter Gen-V L8T engine.
Being heavily supported by GM, the new iron-block “truck engine” is not only a workhorse, but also slated in the performance catalog as the next big crate engine offering. Seeing that, ATI knew it was an application they had to develop parts for. “Knowing that the L8T was going to be a stout crate engine, and the other applications for it required robustness, we knew we had to offer a Super Damper for it,” says JC Beattie, Jr. “Pretty much all of our applications are overbuilt as standard, so making something that would handle the task wasn’t an issue.”
The New Kid On The Block
With the decision made to support the platform, initial R&D came via an unusual channel. “It really came to us through a customer using the engines in a military application, and we really learned a lot about the L8T that way,” explains Beattie. “Dimensionally, it was an easy fit, since almost nothing changed [between the L8T and other Gen-V applications]. Drive-wise, if you’re putting a blower on it, we can go bigger [with the bolt on front pulley diameter]. If you’re going to go drifting or road racing, we can go smaller, so the accessories aren’t spinning at such a sustained RPM all the time. This was really an out-of-the-box application whose development fell in line with what we normally do, and everything worked well.”
What really proves to be different on the L8T damper is that there is one base part number that covers almost all L8T-based applications, and then some. Even with that, the design is still able to cover all eventualities. “The damper design is very modular. We can bolt a lot of things to it, or we can put a bigger shell on it depending on where the drive locations line up,” says Beattie.
“[Not having three different length hubs like the LS] It makes life a lot easier. It’s just a standard length and we have a simple, single part number [for the damper assembly itself] and you’re good to go. This part already comes with the best hub we offer – 4140 heat-treated steel, with a single keyway standard (you can get it dual keyed easily enough), with an aluminum shell and all of the pullies are already aluminum.”
L8T, LV3, L84, and L87 – Oh My!
While some might be concerned that the aluminum shell is a higher-end option that brings higher-end costs, the opposite is true, cost-wise. “Some people are pretty hung up on having a steel damper, and in a lot of applications, the aluminum one is actually more affordable at the end of the day,” Beattie relates. “Lifespan-wise, the aluminum has a failure point somewhere north of 50 million engine cycles, which is five 24 Hours of LeMans races in a row. For a street application, we’ll never see that in our lives.”
While there is one part number for the damper itself, there are six different part numbers for accessory pulley options specific to the L8T damper ranging from 10-percent underdrive to 30-percent overdrive, with a variety of groove counts, covering all of the bases. “GM put a lot of money into [the L8T] program and I think it’s going to be around for a while,” says Beattie. With ATI Performance Products’ help, the L8T’s future as a high-performance platform is just getting started.
ATI P/N: 917306 replaces GM P/N: 12680364 and fits GM’s 2020-up 6.6L L8T crate engine, as well as the 2018-up 4.3L LV3, 2019-up 5.3L L84, and 6.2L L87 engines. The L8T damper is SFI 18.1-certified and comes with laser-etched timing marks.