More Hoopla From Cadillac Now About The 4.2L
03-29-2018, 10:46 PM
#21
Race Director
You guys are finally starting to understand. C8 is a front engine car, the mid engine car is a Caddy halo car to "elevate the brand".
03-29-2018, 11:41 PM
#22
The 718, as well as the 911, competes in the same price category as the base Stingray to Z06. That is all GM is going to care about. Selling more cars.
BTW, they have been testing a V6 in the 718 recently and I expect them to ditch the current engine soon. Things change.
BTW, they have been testing a V6 in the 718 recently and I expect them to ditch the current engine soon. Things change.
Last edited by jma242; 03-29-2018 at 11:42 PM.
03-30-2018, 02:00 AM
#23
Burning Brakes
D
Johan is a Brand Manager, which is akin to being a VP at a bank - about two rungs up from the coffee boy. He does not dictate how GM allocates engines to platforms. Chevy will certainly not get Cadillac's 4.2L V-8 in MY2019, because 1) there is no need for it in the C7 - the C8 goesn't debut until MY2020, and 2) the only "Cadillac" part on this engine is the top cover. A GM 4.2L V-8, probably in a higher state of tune which shares 95% of the PBOM with the "Cadillac V-8", will certainly be in the 2020 Corvette.
Not sure if anyone has looked at the geometry on this 4.2 L to see how big a piston would fit in the block if they bored it out, but it is conceivable that the 5.5L could be done the same way they derived the LS7 from the LS1/2. Anyone have any data on how far apart the bore centers are on this dude ? I think the pistons are 86 mm, so a 5.5L (assuming proportional stroke) would need to fit pistons up to 98 mm in diameter.
Not sure if anyone has looked at the geometry on this 4.2 L to see how big a piston would fit in the block if they bored it out, but it is conceivable that the 5.5L could be done the same way they derived the LS7 from the LS1/2. Anyone have any data on how far apart the bore centers are on this dude ? I think the pistons are 86 mm, so a 5.5L (assuming proportional stroke) would need to fit pistons up to 98 mm in diameter.
03-30-2018, 02:21 AM
#24
Le Mans Master
dcbingaman: see posts earlier in the thread. Even if the 4.2L could be siamesed like LS7 (and it's highly boosted so you can't) you don't get very far.
03-30-2018, 02:32 AM
#25
Burning Brakes
The LS7 wasn't built for 20 PSI boost, so decreasing the land from the LTA's .390" to the LS7's .275" is not feasible.
The LT5(4.060" X 3.625" and 4.4" bore centers) is built for boost(and less than 20 pounds, actually 9.71 psi) and has a .340" land between the cylinders.
The 4.2L Caddy engine has 3.39" bore and a 3.55" stroke and 3.78" bore centers(with a .390" land between centers).
Boring the 4.2L is out of the question with 20 pounds of boost.
That leaves increasing the stroke. To get 5.5L of displacement with a 3.39" bore would require a 4.609" stroke.
4.609" stroke is crazy talk. The deck height would have to be raised, making the engine taller, and making the deck height taller would not be using the LTA block, etc.
If they did bore the 4.2L 3.39" out .050" to 3.44" to have the same land as the LT5, it would still take a 4.476 " stroke to achieve a 5.5 liter displacement and a 4.476" stroke is still crazy talk. And those thinner cylinder walls might not take to kindly to 20 pounds of boost.
The 4.2L LTA engine was designed around getting the most efficient use of packaging thus they made the block much smaller than the LT5 block.
If GM plans to have a 5.5L DOHC engine, then they would probably use a 6.2L block(but not a LT1 block) so they can use the existing transfer lines, etc for the machining etc, with a slightly smaller bore or possible a slightly shorter stoke or a combination of the two. I would bet they would go with a slightly smaller bore, thus increasing the thickness of the iron liners, making high boost more practical. Using the same stroke of the present 6.2L engine, but with a slightly smaller bore, would allow them to use the crankshaft and rods out of the LT5's parts bin. I really doubt they would come out with a new block with slightly less bore centers just to drop down to 5.5 liters displacement from 6.2L.
As a side note, the Northstar engine in the XLR was 4.6L and they decreased the bore .080", to increase the land for improved head gasket sealing, and to increase the wall thickness for improved strength with the 4.4L XLR-V(supercharged) engine. And the XLR-V had nowhere near 20 pounds of boost(actually it had 12 psi boost). The Northstar had a 4.00" bore spacing(.220" more than the 4.2L LTA engine) and it was reported to be able to be opened up to 5.4L(but never was in a production vehicle)
The LT5(4.060" X 3.625" and 4.4" bore centers) is built for boost(and less than 20 pounds, actually 9.71 psi) and has a .340" land between the cylinders.
The 4.2L Caddy engine has 3.39" bore and a 3.55" stroke and 3.78" bore centers(with a .390" land between centers).
Boring the 4.2L is out of the question with 20 pounds of boost.
That leaves increasing the stroke. To get 5.5L of displacement with a 3.39" bore would require a 4.609" stroke.
4.609" stroke is crazy talk. The deck height would have to be raised, making the engine taller, and making the deck height taller would not be using the LTA block, etc.
If they did bore the 4.2L 3.39" out .050" to 3.44" to have the same land as the LT5, it would still take a 4.476 " stroke to achieve a 5.5 liter displacement and a 4.476" stroke is still crazy talk. And those thinner cylinder walls might not take to kindly to 20 pounds of boost.
The 4.2L LTA engine was designed around getting the most efficient use of packaging thus they made the block much smaller than the LT5 block.
If GM plans to have a 5.5L DOHC engine, then they would probably use a 6.2L block(but not a LT1 block) so they can use the existing transfer lines, etc for the machining etc, with a slightly smaller bore or possible a slightly shorter stoke or a combination of the two. I would bet they would go with a slightly smaller bore, thus increasing the thickness of the iron liners, making high boost more practical. Using the same stroke of the present 6.2L engine, but with a slightly smaller bore, would allow them to use the crankshaft and rods out of the LT5's parts bin. I really doubt they would come out with a new block with slightly less bore centers just to drop down to 5.5 liters displacement from 6.2L.
As a side note, the Northstar engine in the XLR was 4.6L and they decreased the bore .080", to increase the land for improved head gasket sealing, and to increase the wall thickness for improved strength with the 4.4L XLR-V(supercharged) engine. And the XLR-V had nowhere near 20 pounds of boost(actually it had 12 psi boost). The Northstar had a 4.00" bore spacing(.220" more than the 4.2L LTA engine) and it was reported to be able to be opened up to 5.4L(but never was in a production vehicle)
03-30-2018, 04:29 AM
#26
I'm starting to believe the C8 will be under Cadillac which will not be named "Corvette" anymore, so Cady's president is right, that engine isn't going to "Corvette" and Corvette Chief is right, there won't be a C8 ME, because it won't be called C8.
Looks like Cadillac is going to own all the high-end GM cars, which is fine getting away from Chevy dealers.
Looks like Cadillac is going to own all the high-end GM cars, which is fine getting away from Chevy dealers.
03-30-2018, 06:23 AM
#27
Le Mans Master
Less Hoopla about....more reality!? ;)
Like Skank said, ME all current models, add C8R!
All current engines as the electric stuff evolves fast!
Autonomousness explains (720s MT test on street tires)!?
All current engines as the electric stuff evolves fast!
Autonomousness explains (720s MT test on street tires)!?
03-30-2018, 07:08 AM
#28
Race Director
The 718, as well as the 911, competes in the same price category as the base Stingray to Z06. That is all GM is going to care about. Selling more cars.
BTW, they have been testing a V6 in the 718 recently and I expect them to ditch the current engine soon. Things change.
BTW, they have been testing a V6 in the 718 recently and I expect them to ditch the current engine soon. Things change.
Not sure the 718 is selling well so change eventually will occur.
Pricewise the corvette and the least expensive Porsche lineup and certain 911 s do compete.
Today's C7 Corvette runs from 55 grand to 150 grand depending on options etc...
Probably add five or ten grand to today's msrp to find the rear mid engines pricing for the c8.
03-30-2018, 10:43 AM
#29
I really do not see this car being a Cadillac (leaning on C7pimp word when he saw the car, he saw a new corvette emblem on hood). But I do believe the corvette will have this motor, or some similar variant of it....
03-30-2018, 11:01 AM
#30
Burning Brakes
As the British say about lawn maintenance, to get a good stand of grass, you need to seed, fertilize, water, mow and aerate, and if you do it all properly, in about 600 years you'll have perfect grass.
Same goes for Cadillac, if they REALLY want to compete with Mercedes-Benz, then they need to build about 5 generations of superior sedans at better prices and settle for smaller margins. While I am a big GM fan, my next 4-door sedan will be either a E-Class or an S-Class Mercedes, because Cadillac is just not there yet....maybe in 2050, but not now.
03-30-2018, 11:38 AM
#31
Le Mans Master
Bingo! GM's BoP!? ;)
CT5.R Street Sport Cadillac gets the 500 HP V8TT hot V to race!
(My LS6 history car with all the extra engine room joke; I had the wrong car before here and got hassled
)
And/or
https://youtu.be/zNcJSAYhm0o
And
https://jalopnik.com/the-m8-gte-is-bmws-badass-return-to-le-mans-1803778548
The C8R Purist Sport Corvette gets the ME frame!
(My LS6 history car with all the extra engine room joke; I had the wrong car before here and got hassled
)And/or
https://youtu.be/zNcJSAYhm0o
And
https://jalopnik.com/the-m8-gte-is-bmws-badass-return-to-le-mans-1803778548
The C8R Purist Sport Corvette gets the ME frame!
Last edited by johnglenntwo; 03-31-2018 at 07:26 AM.
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03-31-2018, 10:29 AM
#32
Think of this one, Just maybe this ME car will never be called a Corvette hence why he is saying it’s not going into the Corvette. It could be marketed as a whole new Horse into the Chevrolet stable.
Last edited by C5Driver; 03-31-2018 at 10:33 AM.
03-31-2018, 11:03 AM
#33
Safety Car
Same goes for Cadillac, if they REALLY want to compete with Mercedes-Benz, then they need to build about 5 generations of superior sedans at better prices and settle for smaller margins. While I am a big GM fan, my next 4-door sedan will be either a E-Class or an S-Class Mercedes, because Cadillac is just not there yet....maybe in 2050, but not now.
03-31-2018, 11:43 AM
#35
03-31-2018, 12:12 PM
#36
Safety Car
GM is not stupid, not going to through away our collective 66 years of Corvette passion!
Most of us have a many-decades emotional commitment to owning a Corvette. It was the car we read about in Car & Driver when we were around 10 years old. We belong/belonged to Corvette clubs, now belong to the National Corvette Museum, make periodic trips to Bowling Green and similar.
There is no National Viper Museum, no U.S. National Porsche Museum, not a National Mustang Museum.
Many of our true life-long friends we currently have, are friends we initially made because of our meeting another Corvette owner. We still make strong new friendships now because of their similar love of their Corvette.
GM understands and feels our passion for our Corvettes. The Corvette team itself has a passion the Corvette, not just as an exciting job, but they personally (with their own money) own a Corvette, their Dads own a C7, etc. Their Corvette passion is real!
GM will not stupidly throw away 66 years of our Corvette passion, will not debut ZORA’s 50+ year dream by debuting a ME Cadillac, nor trash for many of us, our decades long dream of owning that elusive mid engine Corvette.
True, it will be a business decision. What is overlooked because of current C7 discounts, is that per the ultimate long term GM insider, GM has made a killing financially with the C7.
GM will be smart. The best business decisions reinforce a business’ best asset, e.g., its brand! GM will be smart and debut a 2020 ME Corvette — reinforcing one of its strongest assets, will also smartly continuing C7 FE production for those who prefer our wonderful, classic, long hood/short rear Corvettes.
Most of us have a many-decades emotional commitment to owning a Corvette. It was the car we read about in Car & Driver when we were around 10 years old. We belong/belonged to Corvette clubs, now belong to the National Corvette Museum, make periodic trips to Bowling Green and similar.
There is no National Viper Museum, no U.S. National Porsche Museum, not a National Mustang Museum.
Many of our true life-long friends we currently have, are friends we initially made because of our meeting another Corvette owner. We still make strong new friendships now because of their similar love of their Corvette.
GM understands and feels our passion for our Corvettes. The Corvette team itself has a passion the Corvette, not just as an exciting job, but they personally (with their own money) own a Corvette, their Dads own a C7, etc. Their Corvette passion is real!
GM will not stupidly throw away 66 years of our Corvette passion, will not debut ZORA’s 50+ year dream by debuting a ME Cadillac, nor trash for many of us, our decades long dream of owning that elusive mid engine Corvette.
True, it will be a business decision. What is overlooked because of current C7 discounts, is that per the ultimate long term GM insider, GM has made a killing financially with the C7.
GM will be smart. The best business decisions reinforce a business’ best asset, e.g., its brand! GM will be smart and debut a 2020 ME Corvette — reinforcing one of its strongest assets, will also smartly continuing C7 FE production for those who prefer our wonderful, classic, long hood/short rear Corvettes.
Last edited by elegant; 03-31-2018 at 12:14 PM.
03-31-2018, 01:27 PM
#38
If they do, it shouldn't be called a Chevy (IMO).
GM is not stupid, not going to through away our collective 66 years of Corvette passion!
Most of us have a many-decades emotional commitment to owning a Corvette. It was the car we read about in Car & Driver when we were around 10 years old. We belong/belonged to Corvette clubs, now belong to the National Corvette Museum, make periodic trips to Bowling Green and similar.
There is no National Viper Museum, no U.S. National Porsche Museum, not a National Mustang Museum.
Many of our true life-long friends we currently have, are friends we initially made because of our meeting another Corvette owner. We still make strong new friendships now because of their similar love of their Corvette.
GM understands and feels our passion for our Corvettes. The Corvette team itself has a passion the Corvette, not just as an exciting job, but they personally (with their own money) own a Corvette, their Dads own a C7, etc. Their Corvette passion is real!
GM will not stupidly throw away 66 years of our Corvette passion, will not debut ZORA’s 50+ year dream by debuting a ME Cadillac, nor trash for many of us, our decades long dream of owning that elusive mid engine Corvette.
True, it will be a business decision. What is overlooked because of current C7 discounts, is that per the ultimate long term GM insider, GM has made a killing financially with the C7.
GM will be smart. The best business decisions reinforce a business’ best asset, e.g., its brand! GM will be smart and debut a 2020 ME Corvette — reinforcing one of its strongest assets, will also smartly continuing C7 FE production for those who prefer our wonderful, classic, long hood/short rear Corvettes.
Most of us have a many-decades emotional commitment to owning a Corvette. It was the car we read about in Car & Driver when we were around 10 years old. We belong/belonged to Corvette clubs, now belong to the National Corvette Museum, make periodic trips to Bowling Green and similar.
There is no National Viper Museum, no U.S. National Porsche Museum, not a National Mustang Museum.
Many of our true life-long friends we currently have, are friends we initially made because of our meeting another Corvette owner. We still make strong new friendships now because of their similar love of their Corvette.
GM understands and feels our passion for our Corvettes. The Corvette team itself has a passion the Corvette, not just as an exciting job, but they personally (with their own money) own a Corvette, their Dads own a C7, etc. Their Corvette passion is real!
GM will not stupidly throw away 66 years of our Corvette passion, will not debut ZORA’s 50+ year dream by debuting a ME Cadillac, nor trash for many of us, our decades long dream of owning that elusive mid engine Corvette.
True, it will be a business decision. What is overlooked because of current C7 discounts, is that per the ultimate long term GM insider, GM has made a killing financially with the C7.
GM will be smart. The best business decisions reinforce a business’ best asset, e.g., its brand! GM will be smart and debut a 2020 ME Corvette — reinforcing one of its strongest assets, will also smartly continuing C7 FE production for those who prefer our wonderful, classic, long hood/short rear Corvettes.
Of all American car models ever built, only the Corvette and the Mustang enjoy international name recognition.
That says something.
03-31-2018, 01:28 PM
#39
Pickup Engine's
I think if you know what direction General Motors is taking with its future pick up Engine's you will have a good idea of what the Corvette engine will be like. I believe the talk of the V 6 and DOHC is not what we will see. We will see a big price increase in the cars If they go with DOHC and turbo charging.
03-31-2018, 01:42 PM
#40
Team Owner
LOL, I've never heard that one before.
I suppose it's possible and, AFAIK, unprecedented by GM.
If they do, it shouldn't be called a Chevy (IMO).
Well said.
Of all American car models ever built, only the Corvette and the Mustang enjoy international name recognition.
That says something.
I suppose it's possible and, AFAIK, unprecedented by GM.
If they do, it shouldn't be called a Chevy (IMO).
Well said.
Of all American car models ever built, only the Corvette and the Mustang enjoy international name recognition.
That says something.
After all, David Hill was an engineer at Cadillac from 1965 to 1992 and then the Corvette Chief Engineer from 1992 to 2006.
He has the blood of both flowing in his veins.