Cadillac Engine for the C8?
11-14-2018, 10:17 PM
#1
Le Mans Master
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St. Jude Donor '15-'16,'18
11-14-2018, 10:37 PM
#2
Safety Car
Explicit and direct denial by Cadillac, though that is no surprise. And additional behind the scenes information confirming the public, official denial.
I originally doubted Cadillac’s denial; now I accept that it is completely accurate.
I originally doubted Cadillac’s denial; now I accept that it is completely accurate.
Last edited by elegant; 11-15-2018 at 08:42 AM.
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Zaro Tundov (11-15-2018)
11-15-2018, 09:41 AM
#4
Le Mans Master
I like the Cad black wing emblem design.
Tribute to Corvette sport emblem.
Still retains a Caddy "V" series motif.
Engine sharing between Cad & Vette makes bean counter sense.
Tribute to Corvette sport emblem.
Still retains a Caddy "V" series motif.
Engine sharing between Cad & Vette makes bean counter sense.
11-15-2018, 09:59 AM
#5
It uses what the company calls a hot V design, with exhaust manifolds placed in the valley between the two cylinder banks instead of exiting on the outside. The twin-scroll turbochargers are also integrated into the manifolds at the top of the engine, creating a very compact DOHC powerplant that Cadillac also says has less turbo lag. At full speed, those turbos can add up to 20 pounds of boost. 
https://www.motor1.com/news/266926/c...-v8-blackwing/
https://www.motor1.com/news/266926/c...-v8-blackwing/
Last edited by norge1956; 11-15-2018 at 10:30 AM.
11-15-2018, 10:18 AM
#6
Team Owner
It uses what the company calls a hot V design, with exhaust manifolds placed in the valley between the two cylinder banks instead of exiting on the outside. The twin-scroll turbochargers are also integrated into the manifolds at the top of the engine, creating a very compact DOHC powerplant that Cadillac also says has less turbo lag. At full speed, those turbos can add up to 20 pounds of boost.
https://www.motor1.com/news/266926/c...-v8-blackwing/
https://www.motor1.com/news/266926/c...-v8-blackwing/
Last edited by JoesC5; 11-15-2018 at 10:20 AM.
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ArmchairArchitect (11-21-2018)
11-15-2018, 10:33 AM
#8
The engines will be hand-built at GM’s Bowling Green, KY, Performance Build Center, a part of the Chevrolet Corvette assembly plant where the Corvette Z06 LT4 small-block V8 are screwed together. Each of the new Cadillac engines will be autographed with the builders signature.
https://www.chevyhardcore.com/tech-s...win-turbo-v-8/
https://www.chevyhardcore.com/tech-s...win-turbo-v-8/
11-15-2018, 10:38 AM
#9
Drifting
The C8's DOHC V8 will be built with the same engine architecture as Cadillac's hot V 4.2TT DOHC V8. Better to think of it as a GM Powertrain DOHC V8 architecture that will be shared among all the brands with each having their own version. Based on the leaked CAD drawings the C8's DOHC V8 will have twin turbos mounted on the engine's sides right off the headers.
We have two different rumors regarding the "Z" engines (all agree on the base having an updated LT1 with ~520hp):
Rumor 1:
5.5L NA DOHC V8 with a redline just under 9000rpm.
5.5TT DOHC V8.
Rumor 2:
4.2TT DOHC V8
5.5TT DOHC V8
While I would rather have the naturally aspirated 5.5 DOHC V8, I believe the second rumor is the correct one because lower revving twin turbo V8s are more fuel efficient than a mad revving NA V8.
Even more telling is that Cadillac's hot V is already in production at the new Performance Build Center at BGA.
We have two different rumors regarding the "Z" engines (all agree on the base having an updated LT1 with ~520hp):
Rumor 1:
5.5L NA DOHC V8 with a redline just under 9000rpm.
5.5TT DOHC V8.
Rumor 2:
4.2TT DOHC V8
5.5TT DOHC V8
While I would rather have the naturally aspirated 5.5 DOHC V8, I believe the second rumor is the correct one because lower revving twin turbo V8s are more fuel efficient than a mad revving NA V8.
Even more telling is that Cadillac's hot V is already in production at the new Performance Build Center at BGA.
Last edited by Zaro Tundov; 11-15-2018 at 10:39 AM.
11-15-2018, 11:06 AM
#11
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St. Jude Donor '15-'16,'18
I still think it is likely we will see a Cadillac version of a ME sports/touring car built at the BG Assembly Plant.
11-15-2018, 11:37 AM
#12
Drifting
Thanks, that's the first power curve I've seen for the Blackwing. Compared to BMW/MB it looks like Cadillac sacrificed a little bottom end torque for higher peak torque.
I hope the C8's 4.2TT DOHC V8 has a higher redline and a flatter torque curve.
I hope the C8's 4.2TT DOHC V8 has a higher redline and a flatter torque curve.
Never seen this engine mentioned, 7.0 ltr. DOHC 750hp 8000 rpm based on LS7 block from Mercury Racing, the guys responsible for the first ZR1 engine
11-17-2018, 10:56 PM
#14
Race Director
Problem with a DOHC engine is that they are by nature a high reving engine. To get them to perform you have to ring their necks. Higher rpms means shorter engine life. Personally I prefer an engine that can loaf through life and last as long as the car.
11-18-2018, 12:20 AM
#15
Banned Scam/Spammer
DOHC engine life is just as capable as an OHV engine.
11-18-2018, 07:08 AM
#16
Drifting
It's probably all moot anyways, since we're hearing the DOHC V8s used in the C8 will pack a brace of turbos. I'm still hoping for the 5.5L to be NA.
11-19-2018, 10:51 AM
#17
Burning Brakes
That's part of their charm. It takes skill to get the most out of a high revving engine, but it's also more rewarding. In practice they seem to last as long as an old school pushrod if maintained well.
It's probably all moot anyways, since we're hearing the DOHC V8s used in the C8 will pack a brace of turbos. I'm still hoping for the 5.5L to be NA.
It's probably all moot anyways, since we're hearing the DOHC V8s used in the C8 will pack a brace of turbos. I'm still hoping for the 5.5L to be NA.
11-21-2018, 11:14 AM
#18
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Some posts may have associated lack of low end torque with DOHC engines, however the DOHC engines with FPC are the engines that suffer on low end while of course exhibiting ability to rev higher. Only downsides to DOHC at this point are weight and packaging.
11-21-2018, 01:36 PM
#19
Le Mans Master
Originally Posted by NemesisC5
Some posts may have associated lack of low end torque with DOHC engines, however the DOHC engines with FPC are the engines that suffer on low end while of course exhibiting ability to rev higher. Only downsides to DOHC at this point are weight and packaging.
11-21-2018, 06:04 PM
#20
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The whole point of going DOHC is to be able to downsize the engine and rev it higher and make the same HP as the larger engine but at a higher rpm. The downsized engine will require less fuel at common driving rpms and will more easily meet CAFE requirements. The smaller engines will also avoid heavy fines in other counties. The loss of low end torque is a result of the loss of cubic inches.
Flat plane crankshafts produce more efficient exhaust scavenging and don't have the massive counterweights of crossplane crankshafts enabling ability to rev quicker and higher. The lack of counterweights is a limiting factor as displacement goes.
Many variables at work in this new equation for Corvette. Displacement possibly more than new Cadillac engine however I don't expect 5.5 litre, I think that number get tossed around often because it's been used in the racing program for years. We'll all have to wait and see.