pontiac solistice gxp, new key features for ecotec II

[simonepietro]

provo a richiedere, ho salvato solo il documento di testo.poi purtroppo il pd.f era realizzato dal conoscente per comodità sua infatti non vi erano le immagini che venivano indicate nel testo ,i cui riferimenti a queste ultime io ho tolto dal tutto

[simonepietro]

specifiche tecniche complete del 2000 ecotec supercharger dgi e ci sono alcune novità. doppi variatori di fase e produzione in u.s.a. Ho l'impressione che ritroveremo parecchie soluzioni di questa unita GM sul probabile 2.200 jts turbo destinato alle alfa romeo

NEW ECOTEC 2.0-LITER DIRECT INJECTION TURBO ENGINE

Advanced Combustion Technology Improves Power and Efficiency in

the 2007 Pontiac Solstice GXP

PONTIAC , Mich. – General Motors introduces the Ecotec 2.0-liter Turbo

engine in the 2007 Pontiac Solstice GXP, making it GM’s first direct injection

offering in North America . Gasoline direct injection technology helps the

Ecotec engine produce more power while maintaining the lower fuel

consumption of a small displacement port-injected engine. It produces 260

horsepower (194 kW) and 260 lb.-ft. of torque (353 Nm),* making it GM’s

highest specific output engine ever, at 2.1 horsepower per cubic inch of

displacement (130 hp / 97 kW per liter), and the most powerful production

engine in the Ecotec family.

Variable valve timing and an intercooled, twin-scroll turbocharging system are

used to optimize the Ecotec 2.0-liter Turbo engine’s performance. It was

developed with the global resources of GM Powertrain in the United States

and Europe , drawing on expertise from the naturally aspirated Ecotec 2.2-liter

direct injection engine used in some European applications and the 2.0-liter

turbocharged engines already in production.

With direct injection, fuel is delivered directly to the combustion chamber to

create a more complete burn of the air/fuel mixture. Less fuel is required to

produce the equivalent horsepower, especially at normal cruising speeds, of a

conventional port-injection combustion system.

“Direct injection technology works well with turbocharging and helps deliver a

great balance of power and economy,” said Ed Groff, assistant chief engineer,

Ecotec 2.0-liter Turbo engine. “The Ecotec 2.0-liter Turbo produces the power

expected of a V-6, but in a smaller, more efficient package – and the driving

response is simply terrific.”

A dual-scroll turbocharger with a lightweight turbine provides nearly instant

power and an air-to-air intercooling system bolsters the turbo’s performance

by reducing inlet temperatures. Dual cam phasing complements the

turbocharging system by optimizing valve timing at lower rpm for best turbo

response and quick engine torque build-up time.

The Ecotec 2.0-liter Turbo uses a stronger, “Gen II” Ecotec engine block,

which was developed with input from racing experience to support increased

horsepower and torque. The cylinder block bulkheads – the areas where the

main bearing caps are attached – and the bore walls are enlarged for

strength. Other areas of the engine were enhanced to reinforce the structure

and the water jacket is deeper for added cooling capacity and improved

cylinder bore roundness. This architecture is shared with the 2.4-liter Ecotec

engine that debuted in the Pontiac Solstice roadster.

Highlights of the Ecotec 2.0-liter Turbo engine include:

• Steel crankshaft

• Forged connecting rods

• Forged oil-galley pistons

• Jet-spray piston cooling

• 9.2:1 compression ratio

• Aluminum cylinder head with sodium-filled exhaust valves

• High-pressure engine-driven fuel pump

• Variable pressure fuel rail

• Dual-scroll turbocharger

Components including the steel crankshaft, forged connecting rods and

forged pistons are high-strength items that provide strength and enhance

durability. Jet-spray oil cooling directed toward an oil-galley piston help reduce

piston temperatures. The system delivers pressurized oil to continuously

lubricate and cool the pistons, which reduces friction and noise and ensures

durability for the engine’s higher power levels. To enhance combustion, the

piston tops feature a dish shape that deflects injected fuel toward the spark

plugs.

To accommodate the direct injection system, the Ecotec 2.0-liter Turbo has a

unique cylinder head and intake manifold. The cylinder head incorporates

mounting locations for the fuel injectors – which are typically mounted in the

intake ports or intake manifold on port injection engines. A high-pressure fuel

pump delivers fuel to a variable-pressure fuel rail. Fuel enters the combustion

chamber through precision multi-hole fuel injectors. The fuel pump, fuel rail

pressure, fuel injection timing, and injection duration are controlled by the

engine control module. In this way, fuel is metered and delivered in a finely

atomized spray.

Apart from the mounting positions of the fuel injectors, the cylinder head has

conventional port and combustion chamber designs, although both are

optimized for direct injection and high boost pressures. The sodium-filled

exhaust valves and stainless steel exhaust manifold are durable components

designed to stand up to the high-performance capability of the engine.

The unique cylinder head, fuel system, pistons, intake manifold, and the dualscroll

turbocharger are the only major components that differentiate the 2.0-

liter Turbo from other members of the Ecotec engine family. Mobil 1 synthetic

engine oil is installed at the factory. Synthetic oil was selected for its frictionreducing

capabilities and high-temperature performance.

How direct injection works

Gasoline direct injection differs from the fuel delivery process of a

conventional engine by delivering fuel directly into the combustion chamber,

where it is mixed with air drawn in to the chamber. The combustion process of

conventional fuel injected engines uses air and fuel that are mixed in the

intake port or intake manifold prior to being introduced into the combustion

chamber. Direct injection is a continuation of the evolutionary process of

moving the fuel introduction point closer to the combustion location to improve

control.

With the Ecotec 2.0-liter Turbo, fuel is introduced directly to the combustion

chamber during the intake stroke. As the piston approaches top-dead center,

the mixture is ignited by the spark plug, giving the name spark ignition direct

injection (SIDI). The fuel injectors are located beneath the intake ports. SIDI

allows the mixture to be “leaner” – less fuel, more air – at full power. SIDI also

permits a slightly higher compression ratio than if the fuel were delivered with

conventional fuel injection. The result is better fuel consumption at part and

full throttle. The engine uses conventional spark plugs similar to other Ecotec

engines.

A high-pressure, returnless fuel system is employed. It features a highstrength

stainless steel fuel line that feeds a variable-pressure fuel rail. Direct

injection requires higher fuel pressure than conventional fuel injected engines

and an engine-driven high-pressure fuel pump is used to supply up to 1,276

psi (150 bar) of pressure. The system regulates lower fuel pressure at idle –

approximately 752 psi (50 bar) and higher pressure at wide-open throttle. The

cam-driven high-pressure pumps works in conjunction with a conventional fuel

tank-mounted supply pump.

Direct injection’s precise fuel delivery enables more complete combustion to

help reduce emissions, particularly on cold starts – the time when most

engine emissions are typically created. Also, direct injection permits higher a

compression ratio in the engine which is a positive influence on fuel economy.

At certain power levels, the boosted SIDI engine can provide significant fuel

economy benefits to the vehicle compared to a larger displacement naturally

aspirated engine.

Turbocharging system

A unique, dual-scroll turbocharger is partnered with an air-to-air intercooling

system to provide up to approximately 20 psi (1.25 bar) of power-enhancing

boost. The dual-scroll turbocharger delivers nearly instant response, as dual

exhaust passages from the engine to the turbine housing guide exhaust gas

to the turbine. This reduces lag time, or spool-up, at low rpm.

“There is virtually no lag with this system,” said Groff. “Throttle response is

immediate. The engine acts like a larger displacement engine.”

The turbocharger is matched to the engine’s displacement and performance

objectives. It is supported by the air-to-air intercooling system, which uses

fresh air drawn through a heat exchanger to reduce the temperature of the

warmer compressed air forced through the intake system by the turbocharger.

Inlet temperature is reduced by approximately 212 degrees (100 degrees C),

enhancing performance because cooler air is denser and promotes optimal

combustion.

Dual cam phasing

The camshafts of the Ecotec 2.0-liter Turbo engine have phasers that support

the continuously variable intake and exhaust valve timing. They also have

cam position sensors, so that the engine control module can accurately

control valve timing. The crankshaft and camshaft position sensors are digital.

A new engine controller, specific to the engine, is used to sense and control

the engine’s performance parameters.

Variable intake and exhaust timing works synergistically with both the

gasoline direct injection and turbocharging systems. The variable engine

timing enabled by cam phasing allows the combustion process to be

optimized. Also, valve “overlap” at low rpm can be adjusted by the controller

to increase the response of the turbocharger, providing a more immediate

feeling of power.

Ecotec family traits

The Ecotec 2.0-liter Turbo is built on a global platform that was designed at

the outset for a range of performance and combustion capabilities. The Gen II

block supports the high-performance demands of the engine, but it is merely a

strengthened version of the original Ecotec architecture. The oil pump, for

example, is the same as used in all other Ecotec engines. It was originally

designed to support high-performance applications of future engines.

“The 2.0-liter Turbo is the pinnacle of Ecotec performance to date, with

additional growth planned. The groundwork for its capabilities was layed on

the drawing table at the very beginning of the Ecotec’s development,” said

Groff. “Prior work and a far-thinking engine design continue to help GM

respond to market demands around the globe more quickly and with greater

accuracy.”

This new Ecotec family member also has traits that have helped forge a

reputation for durability and sophistication:

• Dual overhead camshafts (DOHC) and four valves per cylinder

• Twin counter-rotating balance shafts for operational smoothness

• Electronic throttle control

• Low-friction, roller-finger follower valvetrain with hydraulic lash

adjusters

• Low-maintenance chain-drive for the camshafts

• 58X crankshaft positioning

• Direct-mount accessories, which reduce or eliminate traditional sources

of noise and vibration

• Full-circle transmission mount to reduce noise and vibration

• GM Oil Life System, which can reduce the frequency for oil changes

• Innovative cast-in oil filter housing, which eliminates the need to crawl

under the vehicle to perform oil changes and eliminates throwaway oil

filter cans that retain used oil

As with other engines in the Ecotec family, the 2.0-liter Turbo engine also has

premium features designed to ensure smooth and quiet operation, including a

polymer coating and skirt design for the pistons that reduces noise during cold

starts. An automatic hydraulic tensioner also is used to maintain optimal

tension on the timing chain, which reduces noise and vibration.

General Motors Corp. (NYSE: GM), the world’s largest automaker, has been

the global industry sales leader since 1931. Founded in 1908, GM today

employs about 325,000 people around the world. It has manufacturing

operations in 32 countries and its vehicles are sold in 200 countries . In 2004,

GM sold nearly 9 million cars and trucks globally, up 4 percent and the

second-highest total in the company’s history. GM’s global headquarters are

at the GM Renaissance Center in Detroit .

GM was the first auto manufacturer to

begin using the procedure and expects to use it for all newly rated engines in

the future.

Ecotec 2.0-liter Turbo Specifications

Assembly site: Spring Hill , Tenn.

Application: 2007 Pontiac Solstice GXP

Type: 2.0-liter DOHC turbocharged I4

Displacement

(cu in/ cc):

122 / 1998

Bore x stroke

(in x mm):

3.38 x 3.38 / 86 x 86

Block material: 319 aluminum

Cylinder head material: 356 T6 aluminum

Intake manifold: cast aluminum

Exhaust manifolds: cast stainless steel

Compression ratio: 9.2:1

Valve configuration: overhead cam; four valves per cylinder

Valve lifters: hydraulic lash adjuster, roller finger follower

Firing order: 1-3-4-2

Fuel system:

Gasoline high-pressure, variable-rail pressure, spark

ignition direct injection (SIDI)

Horsepower

(hp / kW):

260 / 194 @ 5300 rpm (SAE certification pending.)*

Torque (lb.-ft. / Nm):

260 / 353 @ 2000 – 5300 rpm (SAE certification

pending.)*

Fuel shut off: 6300 rpm

Crankshaft: forged steel

Connecting rods: forged steel