I want one of these in my 5th gen Z/28!!
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Joined: Dec 1999
Posts: 2,282
I want one of these in my 5th gen Z/28!!
GM'S INNOVATIVE XV16 CONCEPT ENGINE LOOKS TO PAST AND FUTURE
DETROIT - The new GM XV16 concept engine, unveiled in the Cadillac Sixteen show car, builds on GM's leadership in advanced overhead-valve engine design and showcases a number of novel fuel-saving technologies in a surprisingly compact package.
The XV16
GM's XV16 concept engine is a naturally aspirated, all-aluminum 13.6-liter V-16 that generates more than 1000 horsepower (746 kW) and 1000 lbs.-ft. (1356 Nm) of torque. Building on GM Powertrain's small-block V-8 engine architecture, the V-16 features many of GM's advanced next-generation valvetrain and fuel-saving technologies including 3-step Displacement on Demand.
The advanced V-16 concept engine embodies many of GM's innovations in overhead-valve engine architectures. The recently announced new V-12 engine represents GM's expertise with multi-valve overhead camshaft engines.
GM Powertrain had a clear, challenging list of objectives to meet with the new V-16 concept: outstanding quality, reliability and durability, plus turbine-like levels of noise, vibration and harshness. The XV16 needed to be as fuel-efficient as comparable V-10 and V-12 competitive engines. It had to have class-leading specific output and lower engine weight than current big-block V-8s. With all of these requirements, it also had to run on regular unleaded fuel.
All of the objectives were met or exceeded. Even more impressive was the fact that the engineering team working on this project designed, built and demonstrated a working engine in less than eight months.
Simple, elegant design
"The XV16 is an uncomplicated, technically elegant design that sets new levels for efficient, silky-smooth, ultra-quiet operation," said Stephens. "Its power and torque levels are also beyond any other engine of which we know."
High fuel efficiency and low emissions were a top priority in the design and development of the XV16. The XV16 has cylinder head ports and a combustion chamber that have been analytically optimized to provide smooth, quiet and complete combustion. The advanced combustion system reduces emissions and improves fuel economy simultaneously. Sequential multipoint fuel injection is utilized in conjunction with precisely targeted injectors to minimize engine-out emissions. Spark is delivered by high-energy ignition coils for a clean, fast burn. The engine-management system monitors mass airflow to accurately control fuel and spark delivery under all operating conditions.
The concept engine was also designed to be a very space- and weight-efficient engine. The XV16 weighs 695 pounds, 64 pounds less than the Vortec 8100 V-8 featured in the Chevrolet Avalanche, Silverado and Suburban, and GMC Sierra and Yukon XL. The engine's front profile is significantly smaller than that of a dual overhead cam V6/V-8/V-12 design. And the XV16, with twice the number of cylinders, has fewer parts than any DOHC V-8 engine in the industry, thus underscoring another major benefit of overhead-valve designs.
GM Powertrain engineers benchmarked the port geometry of racing engines in designing the XV16. The result is a two-valves-per-cylinder engine with airflow characteristics that rival four-valves-per-cylinder engines.
Computer-aided analysis and simulation were used extensively in the design of some of the major components, such as the block, crankshaft, cylinder head, valvetrain, cooling and lubrication system. GM is recognized as a leader in computer-aided design, which allows engineers to extensively test, analyze and optimize designs in math before moving to expensive hardware. Computer-aided design also accelerates the development process as evidenced by the remarkably short time required to develop this engine.
Key features
The valvetrain is designed to expand the performance envelope of the conventional pushrod, two-valve engine while maintaining the inherent advantages in packaging efficiency and mass.
The XV16's valves are titanium alloy, an extremely lightweight material. The engine also employs titanium alloy valve springs, which are 40 percent lighter than comparable steel designs. The titanium helps increase the springs' natural frequency by 28 percent to allow for higher engine speeds.
Because of its overhead-valve architecture and roots in GM's next-generation small-block V-8, the XV16 is a perfect candidate to feature GM's Displacement on Demand (DoD) fuel-saving technology. This technology enables the engine to run seamlessly on eight or even four cylinders during typical driving conditions to maximize fuel savings.
The XV16 engine is started on all cylinders to provide fast, clean starts in all conditions. Once running, the powertrain control module activates DoD based on speed and load conditions using inputs from a number of sensors. Under light load conditions, the control module automatically closes both intake and exhaust valves on selected cylinders. The valves are reopened to provide the number of cylinders needed for exhilarating acceleration or for hauling heavy loads.
DoD leverages the existing oil pump to provide hydraulic pressure to activate the system. The mechanical actuators are special hydraulic lifters, each with a spring-loaded locking pin that deactivates the cylinders.
These special lifters are designed so that one section can collapse, or expand, into the other section. The two sections can be either coupled or uncoupled to each other through the locking pin. When DoD is initiated, hydraulic pressure is used to dislodge the locking pin and collapse the lifter, thus closing the valve. In reactivation mode, the removal of hydraulic pressure causes the locking pin to return to its latched position, restoring the lifter's normal function.
When in V-8 or V-4 mode, a balanced combination of cylinders would be used to maintain smooth engine operation. Cylinder deactivation-reactivation operation is accomplished in a fraction of a second, making the transition seamless and transparent to the driver.
Based on GM's fuel-economy analysis, on a drive from Detroit to California, the XV16 would operate in eight-cylinder mode 65 percent of the time, four-cylinder mode 30 percent of the time, and in 16-cylinder mode only 5 percent of the time.
With the XV16's 3-step DoD system, you get the added benefit of having greater performance with all 16 cylinders in certain wide-open throttle situations such as safely passing on a two-lane road, climbing a very steep grade, or simply having fun.
As with Displacement on Demand, variable cam phasing further enhances the XV16's fuel economy, emissions and power output. An electro-hydraulically actuated position controller varies the camshaft timing relative to the crankshaft. The use of cam phasing also eliminates the need for an external exhaust gas recirculation (EGR) system to control engine-out NOx emission.
The cam phaser enables increased torque at low speeds by positioning the camshaft with an earlier inlet valve closing to trap more fresh combustion mixture. It also can be used to modify the "effective" compression ratio, allowing for increases in initial compression ratio for improved fuel economy and performance. A phaser authority of greater than 40 degrees allows for overall optimization of power, fuel economy and emissions.
This powerful engine also generates a lot of heat under high load conditions. Piston squirters allow the engine to run at higher engine speeds and loads, and keep the pistons cool. The squirters target oil at the underside of the pistons to help remove heat. Oil is also directed at the cylinder wall to help provide a quieter start-up.
The GM XV16 also uses a dry-sump scavenge pump system integrated with the main oil pressure pump. The dry-sump helps reduce overall height for improved packaging while making the vehicle capable of more aggressive cornering. The system has eight individual scavenge pumps to evacuate oil from the sump for improved performance and fuel efficiency.
"The technologies featured in the XV16 engine - all-aluminum construction, DoD, cam phasing, advanced port and combustion chamber design, piston cooling and advanced materials - are all indicators of where we are headed with our next-generation overhead valve engines," said Stephens. "The Cadillac Sixteen show car is also a great opportunity to showcase the innovative thinking at GM Powertrain."
GM XV16 Specifications
Configuration: 13.6L V-16
Installation: longitudinal RWD
Displacement: 13,600cc
Valvetrain: OHV 2 valves-per-cylinder
Bore x Stroke: 105 mm x 98 mm
Horsepower: 1000 (746 kW) @ 6000 rpm
Torque: 1000 lbs.-ft. (1356 Nm) @ 4300 rpm
Compression ratio: 10.6:1
Firing order: 1-12-8-11-7-14-5-16-4-15-3-10-6-9-2-13
Fuel system: sequential multipoint fuel injection
Recommended fuel: unleaded regular
honda who?
Registered User
Joined: Jul 2002
Posts: 2,472
From: South Bend, Indiana
That freak'n thing has more than 5 X the cylinders my car has, and 13.6 X more displacement
Where do I sign up!?
I would just buy one of those alone, and find a way to fit it into a 4th Gen Camaro and build around it
Where do I sign up!?
I would just buy one of those alone, and find a way to fit it into a 4th Gen Camaro and build around it
Last edited by Meccadeth; Dec 14, 2002 at 06:30 PM.
Registered User
Joined: Feb 2002
Posts: 960
Holy Good God that thing is great, exactly what I was refering to in my post. When oh when will we see something like this. I can't believe the technology, GM has in this thing. I always here those ricers say that only foriegn cars have all the latest advancements, that America is way behind-HA HA in their face, let see them out-do this engine. I would hope they would put this engine into production, but 1000 horses might be a little to much for the public. I can't believe that thing only 695 pounds, that sounds about the same wieght as the LT1 LS1. I won't be able to sleep for days now knowing about this beast.
Registered User
Joined: Jun 2000
Posts: 1,215
From: Coppell, Texas
Originally posted by Aeromaks
$10 says that is going into the super c6 vette.
-Z-016
$10 says that is going into the super c6 vette.
-Z-016
When I first heard the rumors of this engine I figured it would be based on the DOHC Northstar like the XV12 is. The fact that they used OHVs is surprising.
This is very impressive.
Registered User
Joined: Jul 2001
Posts: 581
From: New York, NY
Goddamn!!! No way the final engine will be that powerful though in that car. They toned down the 7.5L V12 in the Cien from 750hp to 500hp. 1000hp is simply insane. What the hell would you put that in???? That would be the most powerful car on the road today, beating out the Buggatti Veyron (sp?) that comes in around 981hp I think, I know theres differences in horsepower ratings and the US hp rating its 981 hp. But damn... I doubt Cadillac will ever make a 1000hp car...
