GM's new 4.2L DOHC twin turbo V-8 !!

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Newold1
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GM's new 4.2L DOHC twin turbo V-8 !!

Post by Newold1 » Thu Nov 29, 2018 9:59 pm

=D> =D> GM releases it's new twin turbo "Hot -V" 4.2 liter DOHC direct injected V8 engine for a couple of Cadillac vehicles. And rumor it will be the first engine for the new 2020 mid engine Corvette. Starts at 550HP and 627lb/ft torque. Plus 600lb/ft between 2200 rpms and 4200rpms. Talk is it's mildly boosted and could be turned up easily to provide over 700hp for the Corvette.
Performance is alive and well at least at GM and Dodge!
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Re: GM's new 4.2L DOHC twin turbo V-8 !!

Post by gruntguru » Thu Nov 29, 2018 11:15 pm

At 2.5 ft lb/cu in I would say it is fairly highly boosted - at least one bar. Its not doing a lot of revs though.

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Re: GM's new 4.2L DOHC twin turbo V-8 !!

Post by grandsport51 » Fri Nov 30, 2018 3:11 am

I admit to not seeing this but I found a link to Caddy Press release in march with specs sayin g booost will be 20 psig
And it will be undersquare with approx. 5000+ psig of fuel pressure with inside the v turbos!

I hope GM GETS VERY WELL MANUFACTURED FUEL LINES!!

https://media.cadillac.com/media/us/en/ ... bo-v8.html

Dave B.
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Re: GM's new 4.2L DOHC twin turbo V-8 !!

Post by hoffman900 » Fri Nov 30, 2018 6:56 am

grandsport51 wrote:
Fri Nov 30, 2018 3:11 am
I admit to not seeing this but I found a link to Caddy Press release in march with specs sayin g booost will be 20 psig
And it will be undersquare with approx. 5000+ psig of fuel pressure with inside the v turbos!

I hope GM GETS VERY WELL MANUFACTURED FUEL LINES!!

https://media.cadillac.com/media/us/en/ ... bo-v8.html

Dave B.
Aren’t diesels well above that?

I’m having flashbacks to when some on here we’re against DI because they thought the cars would explode in accidents. :lol:
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Re: GM's new 4.2L DOHC twin turbo V-8 !!

Post by midnightbluS10 » Fri Nov 30, 2018 7:25 am

grandsport51 wrote:
Fri Nov 30, 2018 3:11 am
I admit to not seeing this but I found a link to Caddy Press release in march with specs sayin g booost will be 20 psig
And it will be undersquare with approx. 5000+ psig of fuel pressure with inside the v turbos!

I hope GM GETS VERY WELL MANUFACTURED FUEL LINES!!

https://media.cadillac.com/media/us/en/ ... bo-v8.html

Dave B.
Why would you be worried about fuel lines? Has gm had an issue with direct injection lines not holding pressure? What's the reasoning behind your comment?
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Re: GM's new 4.2L DOHC twin turbo V-8 !!

Post by Keith Morganstein » Fri Nov 30, 2018 7:41 am

hoffman900 wrote:
Fri Nov 30, 2018 6:56 am
grandsport51 wrote:
Fri Nov 30, 2018 3:11 am
I admit to not seeing this but I found a link to Caddy Press release in march with specs sayin g booost will be 20 psig
And it will be undersquare with approx. 5000+ psig of fuel pressure with inside the v turbos!

I hope GM GETS VERY WELL MANUFACTURED FUEL LINES!!

https://media.cadillac.com/media/us/en/ ... bo-v8.html

Dave B.
Aren’t diesels well above that?

I’m having flashbacks to when some on here we’re against DI because they thought the cars would explode in accidents. :lol:
Common rail diesel injection pressure is in excess of 30,000 PSI.
Automotive Machining, cylinder head rebuilding, engine building. Can't seem to quit #-o

grandsport51
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Re: GM's new 4.2L DOHC twin turbo V-8 !!

Post by grandsport51 » Fri Nov 30, 2018 8:04 am

I'm a little skeptical of OEM's reliability testing before introduction of new technology
When I was a Ford Service Manager we introduced the 2.0 Koln built OHC engine and
Stated that the engine had millions of miles of durability testing in Europe
Well of course the rocker arm otc cam lobes started failing promptly some before 20,000 miles.
Proper Types of oil not specified
The Reynolds metal Vega Bores similarly failing likely because of susceptibility to coolant leaks
And having a tiny cooling capacity.Corrected with "Durabilt" engine blocks
NorthStar and other aluminum block engines head bolt thread failures repaired with Threadsert s
Now the new multiple lawsuits and recalls in re CP-4 Bosch pump failures in diesels because of incompatibility
With US Grade diesel fuel.
Mercedes AMG head bolt and gasket failures.
And hundreds of more examples
So it's just my opinion but I wouldn't own the new engine without a full coverage extended warrantee !!
Dave B.
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Re: GM's new 4.2L DOHC twin turbo V-8 !!

Post by grandsport51 » Fri Nov 30, 2018 8:20 am

And These !
I realize mechanical devices fail but I'd much rather use proven tech.
Maybe I need to buy a "New" 1965 Continental to protect against an EMP attack! LOL
IMG_3325.jpg
IMG_3326.jpg
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Re: GM's new 4.2L DOHC twin turbo V-8 !!

Post by mk e » Fri Nov 30, 2018 8:34 am

grandsport51 wrote:
Fri Nov 30, 2018 3:11 am
I admit to not seeing this but I found a link to Caddy Press release in march with specs sayin g booost will be 20 psig
And it will be undersquare with approx. 5000+ psig of fuel pressure with inside the v turbos!

I hope GM GETS VERY WELL MANUFACTURED FUEL LINES!!

https://media.cadillac.com/media/us/en/ ... bo-v8.html

Dave B.
20psi is a pretty typical boost number these days. I suspect the hp boost for the vette will come mostly from a higher rpm tune. The 3.9L Ferrari turbo peaks is 670hp at 8k....that has to be in the mind of the team working on a midengine vette. If GM can fill the cylinders an rpm bump will give them the ho bumo they need without additional boost...but I read the Ferrari 488 is at 35psi!
Mark
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Re: GM's new 4.2L DOHC twin turbo V-8 !!

Post by novadude » Fri Nov 30, 2018 8:40 am

Here's something I don't understand....

It takes a lot of money to develop a new engine platform. While modern design tools speed up the process, you still need to do reliability testing, emissions certification, etc. There is also expensive tooling required for a new platform.

If you look at GM in the last 20 years, starting with the first LS, right up to the current LT1, there have been significant changes to the V8 platform. Contrast that with the Gen 1 SBC that hung around for 40 years with only minor tweaks.

Sales volumes are way down compared to the Gen 1 SBC era (1 million Impalas produced in 1965 alone, most with v8 power). How can they justify the expense of producing these new designs? Especially something like this 4.2L v8 for niche applications with low sales volumes? From a business perspective, it's hard to see where the payback is on a project like this.

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Re: GM's new 4.2L DOHC twin turbo V-8 !!

Post by 77cruiser » Fri Nov 30, 2018 9:10 am

novadude wrote:
Fri Nov 30, 2018 8:40 am
Here's something I don't understand....

It takes a lot of money to develop a new engine platform. While modern design tools speed up the process, you still need to do reliability testing, emissions certification, etc. There is also expensive tooling required for a new platform.

If you look at GM in the last 20 years, starting with the first LS, right up to the current LT1, there have been significant changes to the V8 platform. Contrast that with the Gen 1 SBC that hung around for 40 years with only minor tweaks.

Sales volumes are way down compared to the Gen 1 SBC era (1 million Impalas produced in 1965 alone, most with v8 power). How can they justify the expense of producing these new designs? Especially something like this 4.2L v8 for niche applications with low sales volumes? From a business perspective, it's hard to see where the payback is on a project like this.
Maybe that's why they closed the plants down. :idea:
Jim

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Re: GM's new 4.2L DOHC twin turbo V-8 !!

Post by xr4x4ti » Fri Nov 30, 2018 9:29 am

novadude wrote:
Fri Nov 30, 2018 8:40 am
Here's something I don't understand....

It takes a lot of money to develop a new engine platform. While modern design tools speed up the process, you still need to do reliability testing, emissions certification, etc. There is also expensive tooling required for a new platform.

If you look at GM in the last 20 years, starting with the first LS, right up to the current LT1, there have been significant changes to the V8 platform. Contrast that with the Gen 1 SBC that hung around for 40 years with only minor tweaks.

Sales volumes are way down compared to the Gen 1 SBC era (1 million Impalas produced in 1965 alone, most with v8 power). How can they justify the expense of producing these new designs? Especially something like this 4.2L v8 for niche applications with low sales volumes? From a business perspective, it's hard to see where the payback is on a project like this.
I think the simple answer is that it is MUCH, MUCH easier to make changes now with all of the modern design tools.

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Re: GM's new 4.2L DOHC twin turbo V-8 !!

Post by Newold1 » Fri Nov 30, 2018 9:42 am

I think sometimes WEon this engine forum should spend a little more time studying and educating ourselves in new engine development offerings and understand in particular in a case such as this before we start making so many OPINIONS not necessarily based on real facts and information.

Some more real information on this new GM RPO LTA twin turbo engine:

1. Development on this engine began over 4 years ago at GM.
2. The engine has undergone over two years of actual on road in testing durability cells at GM.
3.This engine is currently being set up for assembly as we speak at the new GM high performance engine assembly facility at Bowling Green Kentucky
4. 20 psi boost on this new engine design is mild, it can easily sustain 30-40psi of boost for extended horsepower and torque.
5. Having 5500 psi fuel pressure in engine fuel lines is not a problem at GM look at fuel pressure levels in LT5 and Duramax diesels.

Just saying I think a few on here should take a more complementary view point with new engine technology, especially when it comes from a company like GM with incredible engine platform success it has had in the last 20 years or so!

I agree with Hoffan900 here:
WE SHOULD DO MORE HAILING AND LESS BAILING!
JMHO :wink:
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Re: GM's new 4.2L DOHC twin turbo V-8 !!

Post by grandsport51 » Fri Nov 30, 2018 10:10 am

Guys I’m not criticizing new tech .

And after my health issues I might be more critical

But trust me after all my years servicing vehicles at

OEMs testing in environmental test cells and

In AZ and AK DOES NOT SUBSTITUTE FOR END USER

ABUSE!!

It’s my Opinion only but I’ve repaired and been responsible for repairing thousands of vehicles at the OEM level As I’m sure many here have!!
No offense intended but Look at Those recalls on the

BOSCH high pressure fuel pumps.

I personally would buy an F-150 with a 5.0 over
An ecoboost.
Dave B.
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Re: GM's new 4.2L DOHC twin turbo V-8 !!

Post by hoffman900 » Fri Nov 30, 2018 10:25 am

77cruiser wrote:
Fri Nov 30, 2018 9:10 am
novadude wrote:
Fri Nov 30, 2018 8:40 am
Here's something I don't understand....

It takes a lot of money to develop a new engine platform. While modern design tools speed up the process, you still need to do reliability testing, emissions certification, etc. There is also expensive tooling required for a new platform.

If you look at GM in the last 20 years, starting with the first LS, right up to the current LT1, there have been significant changes to the V8 platform. Contrast that with the Gen 1 SBC that hung around for 40 years with only minor tweaks.

Sales volumes are way down compared to the Gen 1 SBC era (1 million Impalas produced in 1965 alone, most with v8 power). How can they justify the expense of producing these new designs? Especially something like this 4.2L v8 for niche applications with low sales volumes? From a business perspective, it's hard to see where the payback is on a project like this.
Maybe that's why they closed the plants down. :idea:
In their eyes, laying off workers and closing plants who are working on unprofitable platforms. Take the money being put into keeping those afloat and put it towards development for new platforms.

GM is hiring, but they’re looking for Eletrical, Software, and Mechanical engineers, technicians, etc. with experience or training in those new technologies.

For the plants, they just have too much capacity.

It sucks, but that’s how private businesses work. In a socialized society the government would pay those workers or they would work for the government, regardless of profit or not. That’s why you always need to be learning and promoting your personal brand. With online degrees and certificates, it’s easier than ever to keep up with emerging technologies and future workforce needs.

You know, pull yourself up by your bootstraps and all that..

Regardless, I’m looking forward to seeing this platform. The efficiencies and power out of the modern crop of engines are pretty incredible. More incredible is how reliably they do it.
Last edited by hoffman900 on Fri Nov 30, 2018 10:31 am, edited 4 times in total.
-Bob

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