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

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

Post by mekilljoydammit » Sun Dec 02, 2018 10:02 am

exhaustgases wrote:
Sat Dec 01, 2018 8:39 pm
... we really need to ask how come those materials aren't used in medium to large scale industrial engines, maybe because some outfits still know how to make something that will last and more trouble free?
Maybe, and this is just me thinking, because a 600hp engine that weighed 3,000 lbs wouldn't be acceptable in a passenger car, but doesn't really matter for industrial equipment?

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

Post by Newold1 » Sun Dec 02, 2018 10:31 am

peejay wrote:
Sun Dec 02, 2018 6:56 am
exhaustgases wrote:
Sat Dec 01, 2018 8:39 pm
lawn mower engine construction materials
Ah, there it is, the false equivalency. Just like the argument I used to see about how the LS1 was sh* because it has the same oil filter size as a Kubota lan tractor. Well, let's see, it has roller rockers, roller cam, a rigid block and a stiff crank, and good fuel and ignition control so the bores and rings wil hardly show wear after 200,000 miles. So with all that in mind, where is all this metal coming from that you need a 1 quart sized oil filter to hope to catch it all? If the concern is volume, the stiffer block means you can keep the tolerances tight so you don't need much volume, and most of the engines have oil coolers so the bearings are being given cool oil instead of hot oil that was heated up even further by a crappy eggbeater of an oil pump.

I can assure you that the alloys and techniques used in manufacturing a modern aluminum engine are closer to F-15 than Tecumseh. There are hundreds/thousands of different aluminum alloys, and modern castng techniques are remarkable. One of my friends does that sort of thing for a living, and on one road trip he was telling me about how modern aluminum castings are much stronger because of how we have the computing power to model how the aluminum shrinks at different rates in the mold as it goes from liquid to 1000F solid to room temperature at different places in the casting. This causes a lot of residual stresses. BUT, if you can model it, you can alter the processes or the part design so that those stresses are gone.

You'd probably have a heart attack to find out that most of the rest of the vehicle is aluminum too. Aluminum subframes, aluminum control arms, aluminum knuckles/uprights, aluminum calipers. Even most low end cars of the past 10-15 years have significant aluminum content, and it's everything but the bearings and bolts as you go up the chain. It's certainly nothing NEW, either - domestically, GM has been using welded-up aluminum extrusions for the front subframe on W-bodies since '01 or so, and they are usually the best part of the car when the rest of the shell is rusted out junk.

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

Post by hoffman900 » Sun Dec 02, 2018 10:42 am

Newold1 wrote:
Sun Dec 02, 2018 10:31 am
peejay wrote:
Sun Dec 02, 2018 6:56 am
exhaustgases wrote:
Sat Dec 01, 2018 8:39 pm
lawn mower engine construction materials
Ah, there it is, the false equivalency. Just like the argument I used to see about how the LS1 was sh* because it has the same oil filter size as a Kubota lan tractor. Well, let's see, it has roller rockers, roller cam, a rigid block and a stiff crank, and good fuel and ignition control so the bores and rings wil hardly show wear after 200,000 miles. So with all that in mind, where is all this metal coming from that you need a 1 quart sized oil filter to hope to catch it all? If the concern is volume, the stiffer block means you can keep the tolerances tight so you don't need much volume, and most of the engines have oil coolers so the bearings are being given cool oil instead of hot oil that was heated up even further by a crappy eggbeater of an oil pump.

I can assure you that the alloys and techniques used in manufacturing a modern aluminum engine are closer to F-15 than Tecumseh. There are hundreds/thousands of different aluminum alloys, and modern castng techniques are remarkable. One of my friends does that sort of thing for a living, and on one road trip he was telling me about how modern aluminum castings are much stronger because of how we have the computing power to model how the aluminum shrinks at different rates in the mold as it goes from liquid to 1000F solid to room temperature at different places in the casting. This causes a lot of residual stresses. BUT, if you can model it, you can alter the processes or the part design so that those stresses are gone.

You'd probably have a heart attack to find out that most of the rest of the vehicle is aluminum too. Aluminum subframes, aluminum control arms, aluminum knuckles/uprights, aluminum calipers. Even most low end cars of the past 10-15 years have significant aluminum content, and it's everything but the bearings and bolts as you go up the chain. It's certainly nothing NEW, either - domestically, GM has been using welded-up aluminum extrusions for the front subframe on W-bodies since '01 or so, and they are usually the best part of the car when the rest of the shell is rusted out junk.

WELL SAID! =D>
This place needs more of this =D>
-Bob

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

Post by Brian P » Sun Dec 02, 2018 11:48 am

exhaustgases wrote:
Sat Dec 01, 2018 8:39 pm
My personal problem is with the use of inferior materials and construction techniques, that are done for manufacturing cost savings, then marketing and the unknowing claim its to make the engine better. If using lawn mower engine construction materials are the best of the best for the general publics vehicles that far exceed the cost of the older stuff of years past, we really need to ask how come those materials aren't used in medium to large scale industrial engines, maybe because some outfits still know how to make something that will last and more trouble free?
Modern aluminum casting used as an engine block is in NO way inferior to cast iron. Of course it requires proper (and different from "the old days") attention to the cylinder wall surfaces, but "modern" designs and manufacturing techniques fully address this.

To my knowledge, Honda has NEVER built an engine with a cast iron block. Honda does have a reputation for building pretty good engines ...

With large industrial engines it doesn't matter if the engine weighs many tonnes. They have much lower power ratings relative to their weight and size so the better thermal conductivity of aluminum would not be an advantage. They don't last forever, either. Most large industrial engines have replaceable cylinder lines ... because they periodically have to be replaced!

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

Post by Truckedup » Sun Dec 02, 2018 11:55 am

Are the engine blocks of the latest PU truck Diesel engine cast iron or aluminum?
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Re: GM's new 4.2L DOHC twin turbo V-8 !!

Post by Olds455 » Sun Dec 02, 2018 11:57 am

mekilljoydammit wrote:
Fri Nov 30, 2018 10:28 am
I'm just waiting for the Corvette version, followed shortly by GM fanboys claiming they were always for DOHC V8s and that they haven't been crapping on DOHC 4-valve engines for the last 20 years.

For places overseas where displacement is taxed more, this might have a better luxury car take-up than pushrod V8s did; god knows BMW seems to sell enough stuff using their turbo V8s. It is kind of a weird seeming thing to see released coming on the heels of mass layoffs though, but if they didn't think the business numbers made sense they wouldn't have done it.
Why would you be waiting for "fan Boys to blah blah blah..."


Who gives a shit what they said 5 years ago or even 20 years ago about DOHC engines? Why let it affect you that much? In the broad scope of things, it means literally nothing. Nothing.

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

Post by Brian P » Sun Dec 02, 2018 12:24 pm

Truckedup wrote:
Sun Dec 02, 2018 11:55 am
Are the engine blocks of the latest PU truck Diesel engine cast iron or aluminum?
A lot of modern diesel engine blocks are made of CGI ... which is a special variety of cast iron but is not plain ordinary grey cast iron.

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

Post by peejay » Sun Dec 02, 2018 12:24 pm

Brian P wrote:
Sun Dec 02, 2018 11:48 am
To my knowledge, Honda has NEVER built an engine with a cast iron block. Honda does have a reputation for building pretty good engines ...

They did. The carbureted 12v engines ("E" series?) used in the mid-80s in the Civic and Accord before they were replaced by the D and F engines respectively, were iron block.

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

Post by peejay » Sun Dec 02, 2018 12:31 pm

Truckedup wrote:
Sun Dec 02, 2018 11:55 am
Are the engine blocks of the latest PU truck Diesel engine cast iron or aluminum?
Neither. They use compacted graphite, which is technically "cast iron" in a broad sense, but is closer to steel or nodular iron in composition than the brittle cheeselike material that we think of as "cast iron".

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

Post by mekilljoydammit » Sun Dec 02, 2018 12:47 pm

Olds455 wrote:
Sun Dec 02, 2018 11:57 am
mekilljoydammit wrote:
Fri Nov 30, 2018 10:28 am
I'm just waiting for the Corvette version, followed shortly by GM fanboys claiming they were always for DOHC V8s and that they haven't been crapping on DOHC 4-valve engines for the last 20 years.

For places overseas where displacement is taxed more, this might have a better luxury car take-up than pushrod V8s did; god knows BMW seems to sell enough stuff using their turbo V8s. It is kind of a weird seeming thing to see released coming on the heels of mass layoffs though, but if they didn't think the business numbers made sense they wouldn't have done it.
Why would you be waiting for "fan Boys to blah blah blah..."


Who gives a shit what they said 5 years ago or even 20 years ago about DOHC engines? Why let it affect you that much? In the broad scope of things, it means literally nothing. Nothing.
... because I find it funny? Other than watching people who are currently LS fanboys try to shift gears without looking foolish, none of this affects me at all; I'm not in the market for any performance car that will use either engine family.

I mean I build rotary engines, it's not like I'm actually heavily affected by what people think. ;)

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

Post by Truckedup » Sun Dec 02, 2018 1:01 pm

peejay wrote:
Sun Dec 02, 2018 12:31 pm
Truckedup wrote:
Sun Dec 02, 2018 11:55 am
Are the engine blocks of the latest PU truck Diesel engine cast iron or aluminum?
Neither. They use compacted graphite, which is technically "cast iron" in a broad sense, but is closer to steel or nodular iron in composition than the brittle cheeselike material that we think of as "cast iron".
Is this material used in any spark ignition engines?
Motorcycle land speed racing... wearing animal hides and clinging to vibrating oily machines propelled by fire

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

Post by Brian P » Sun Dec 02, 2018 1:06 pm


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

Post by pcnsd » Sun Dec 02, 2018 1:35 pm

Reading though, there appears to be lots of conjecture supported by inaccurate narratives resulting in improbable projections of future results. I will wait to see what one of the worlds largest design engineering and manufacturing organization delivers. My expectation as a consumer is 300K-500K miles in standard use and trim with recommended maintenance. How will that not be delivering on reliability? I see a trend to single use components, meaning major parts are less suited to rebuild than in the past. It is indeed the result of optimizing manufacturing to reduce cost and increase reliability, but that comes with the already mentioned expected consumer life that was a pipe dream of in my youth.
A big thank you to William Edwards Deming and the disciplines that resulted from his advice to focus on statistical quality analysis. Continuous improvement, Total Quality Management, Total Productive Maintenance, The Toyota Production system and it's subparts like 5-S, Kaizen, Pull manufacturing, and Kanban signaling, Quick Response Manufacturing and POLCA (Paired overlapping cells with authorization) from the U. of Wisconsin at Madison and many other flavors not mentioned that deliver product quality and reduce cost to the manufacturer and consumer alike.
An extra big thank you to the Japanese manufacturers that pioneered and demonstrated the viability of the concepts before Americans could see the value.

We live in exciting times.
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Re: GM's new 4.2L DOHC twin turbo V-8 !!

Post by Momus » Sun Dec 02, 2018 1:37 pm

Truckedup wrote:
Sun Dec 02, 2018 1:01 pm
peejay wrote:
Sun Dec 02, 2018 12:31 pm
Truckedup wrote:
Sun Dec 02, 2018 11:55 am
Are the engine blocks of the latest PU truck Diesel engine cast iron or aluminum?
Neither. They use compacted graphite, which is technically "cast iron" in a broad sense, but is closer to steel or nodular iron in composition than the brittle cheeselike material that we think of as "cast iron".
Is this material used in any spark ignition engines?
The current NASCAR blocks are each CGI and Ford Motorsport were selling Windsor blocks made from the stuff last time I looked

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

Post by peejay » Sun Dec 02, 2018 2:34 pm

Truckedup wrote:
Sun Dec 02, 2018 1:01 pm
peejay wrote:
Sun Dec 02, 2018 12:31 pm
Truckedup wrote:
Sun Dec 02, 2018 11:55 am
Are the engine blocks of the latest PU truck Diesel engine cast iron or aluminum?
Neither. They use compacted graphite, which is technically "cast iron" in a broad sense, but is closer to steel or nodular iron in composition than the brittle cheeselike material that we think of as "cast iron".
Is this material used in any spark ignition engines?
Technically yes, in that some WRC engines use Diesel blocks to tolerate running 30psi of boost on a 2.0 or 1.6l engine with a stock-block rule. Air is restricted and the fuel is regulated, so power must be made by increasing the compression and running at the threshold of detonation all the time. I don't know what modern practice is but aluminum rods used to be common.

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