A Little News on the Cadillac 4.2DOHC ENGINE and BGA

[Leshelt]

Why GM Finally Let Cadillac Build an All-New Twin-Turbo V8

https://www.popularmechanics.com/car...c-cts-dohc-v8/

Shared from my Google feed

[John]

Thank you very much Leshelt for coming up with more interesting information for us. Good read. A couple of background pieces that will add more to this.

The day that GM announced that new motor, I received an email from a friend. It only said, “Now you know what I have been working on the last two years that I could not earlier tell you about.” His name was actually on the display stand motor at the NYAS, “built by X.” I have a picture of that motor with his name plaque. Let’s call him “George.”

He is a very interesting person, a good friend, who has worked for GM for 40 years, and is part of the secret powertrain building on the grounds of BGA. He and his few colleagues who work in that building refer to it as “the retinal scan” building — for it truly has a special security system, and the regular BGA employees may not ever enter it.

George has build some of the motors that are in Rick Hendrick’s private collection, including as he and Rick learned during a tour George got of Mr. Henrick’s special cars with Mr. H.,several of the motors in Mr. H’s “top ten” cars, were built by George.

In his previous BGA job, George was # 2 within the Powertrain Build Center located inside BGA, so that when someone went and chose the Engine Buid Option for his Corvette motor, George or one of his staff would help you build it (that is before his latest promotion). And George has a few other kudos to his career, for those who saw the 2019 Sebring Orange, low wing ZR1 convertible that was at the LA reveal, the LA show and many other places on the show circuit this past year, would have seen, as I did, his name on its engine build plaque.

When I go to BG, I spent some time with him and his wife, and sorrowfully for me, and properly for him, he never talks about what he is doing. I did once hear him say, about two years ago, that he is aware of every single Corvette powertrain thought 2024. If only we could all learn 1/10th of what he knows about the ME’s power plants!

My guesss is that the day that GM announces the ME’s Z06 equivalent motor, I will get another email from him, saying, “now you know what I have been working on the last two years that I haven’t been able to earlier tell you about.”

And that, as Paul Harvey would have said, is the rest of that story.

[Frenzy36]

This might be new for GM , however Mercedes has had this technology in a hot V for years.

[JB]

This might be new for GM , however Mercedes has had this technology in a hot V for years.

GM pioneered this technology yet you are correct mercedes put the hot vee turbo system into production while gm sat on it for years...

its expensive to produce and for the most part the much less expensive ohv GM supercharged v8 is just as powerful and economical.

JDN and the previous GM ceo believed one of the major reasons cadillac was considered second tier luxury in the market was because they did not have a dohc forced induction engine...

thats not really the case as the soft touch interiors outclass cadillacs
, the exterior styling of cadillacs comes across as cheaper in overall appearance and my absolute favorite failure point of cadillacs is its lease deals suck compared to bmw s...

check any leasing company like www,legendleasing.com and you ll see cadillacs lease deals literally cost the consumer more per month than bmw s...

gm should have run subsidized lease program cars and packages like bmw has done for years...

it was cadillac sales amd marketings biggest failure to provide select “lease value production” packages and programs that the germans have perfected...

it was never the need for a hot vee twin turbo engine...

the LT4 kicks some serious butt..

the cts v’s lack of decent lease deals and of course the consumers desire for AWD in sports sedans that caillac missed the boat on...

mercedes hot vee engine is a sweet but pricey package...and so will cadillacs new hot vee v8...

whose paying for all this exotic ****..?

[Bikerjulio]

I was struck by this

Ninety percent of the 4.2L's torque is available from 2,000 to 5,200 RPM. That low-end grunt lets the CT6 move effortlessly around town and hustle up highway on-ramps without having to rev to the screaming high end of the tachometer. It’s less dramatic than the CTS-V's raucously tuned 6.2L, but more fitting for a car that thinks of itself as refined.

We were always taught the the limitation of the pushrod V8 was valvetrain inertia which limited revs, and that this problem was eased by having an OHC design. To put it another way, the whole point of having a DOHC setup was to permit higher rev limits. The much increased complexity, cost, weight? height? hardly seems worth it to end up with a low revving engine.

[Mobius]

I was struck by this

We were always taught the the limitation of the pushrod V8 was valvetrain inertia which limited revs, and that this problem was eased by having an OHC design. To put it another way, the whole point of having a DOHC setup was to permit higher rev limits. The much increased complexity, cost, weight? height? hardly seems worth it to end up with a low revving engine.

I agree with your points, from a performance perspective.

Engine efficiency and increasing CAFE standards will also factor into GM's DOHC/turbo considerations.

[Frenzy36]

Mercedes Hot Vee Design

[meyerweb]

This specific engine may be limited to Cadillac only, but I seriously doubt GM spent all this money developing a new engine and that none of the benefit of that development will be shared. I would be very surprised if we don't see strikingly similar DOHC V8s showing up in other product lines. They may not be 4.2 liters, they may not be hot-V designs, the heads may be different with different cams, but I'll bet they share a lot of details like bore centers, valve train, oil systems, and more. Developing an all new engine from scratch is a very expensive endeavor, and it would be foolish of GM not to utilize that tech as widely as possible.

[John]

Totally agreee with you meyerweb, that GM is not spending hundreds of millions for development of an engine going into a CT6 (projected annual sales of 2,000-3,000) and even if one were to include the 2021 Escala (again estimated 2,000-3,000 sales per year), that still does not make economic sense to me either.

However, if a variant of that motor were to also be used for a 2021+ Corvette, then the economics of developing this new motor makes total sense. And as you have earlier pointed out, especially interesting that the new 4.2L Cadillac motor is going to be made inside the Bowling Green Assembly Plant.