The official 3500 thread. pics.

[Fierobsessed]

You can't offset grind to .200" The max is .125" the journals are only .250" wider. Would be insane, but not realistically possible.

[Doubt_Incarnate]

i probly missread some stuff up there. but whatever you can offset is doubled but the 360 degree nature of the crank. so i'd still be happy with .25" more oomph. but not wild about custom parts.

[Fiero11]

I believe this 3.5L(94mmx84mm) is the same crank as is in the 3.9L (99mmx84mm). I've heard that the 2006 Impala will have a 3.5L (99mmx76mm) with the same large valves and raised cam as the 3.9L. Maybe GM will support high performance parts for these.

[Froggx]

Nice to see some of the differences in these. Don't the 3400 and 3500 use the same lower intake manifold? I would have thought that the heads would be more similar on the intake ports if they do.

[v6h.o.]

Nice to see some of the differences in these. Don't the 3400 and 3500 use the same lower intake manifold? I would have thought that the heads would be more similar on the intake ports if they do.

Up until now we thought they were the same as they looked it from the exterior.
However as the ports show they're different.

[Froggx]

Ok, so I guess they're the same as far as how the UIM goes on then, but different where it meets the heads, that makes sense in a GM sort of way.

[GPXSS]

3900 3.9L V-6 (LZ9)
2006 model year summary
? All-new engine, optional in 2006 Chevrolet Malibu SS, Malibu Maxx SS, Impala, Monte Carlo, Uplander; Pontiac G6 and Montana SV6; Buick Terraza; and Saturn Relay
? New 60-degree offset bore engine block
? First use of variable valve timing in a cam-in-block engine
? Variable intake manifold
? ?U?-flow coolant design
? Shrouded injectors and returnless fuel system
? Electronic throttle control
? Advanced direct ignition and engine controller
? Piston cooling oil jets
Full descriptions of new or changed features
All-new 60-degree banked V-6
The 3900 V-6 is part of GM?s all-new powerful yet efficient overhead valve V-6 engine family. For 2006, the 3.9L is optional Chevrolet Malibu SS, Malibu Maxx SS, Impala, Monte Carlo, Uplander; Pontiac G6 and Montana SV6; Buick Terraza; and Saturn Relay.
New 60-degree offset bore engine block
The new 3.5L and 3.9L V-6 engines represent an all-new engine design but incorporate some familiar and well-regarded attributes, including a 60-degree ?V? configuration. The 60-degree configuration is naturally balanced, ensuring drivetrain smoothness and eliminating the need for costly balance shafts. The relatively narrow 60-degree V also makes the engine more compact for a variety of applications. This new engine differs from previous GM 60-degree designs with its offset cylinder bores, meaning the intersection of the cylinder bores? centerline is not at the crankshaft centerline. Instead, the intersection is 3 mm below the crankshaft axis. This was done to allow packaging room for the wider bores, as well as the longer stroke of larger-displacement versions within the new engine family. It also allowed for larger cam bearings which, in turn, promoted increased horsepower as larger cam bearings supported the use of a camshaft with higher valve lift profile.
Variable valve timing
Perhaps the most significant technological feature of the new 3.5L V-6 is the adaptation of variable valve timing ? a first for cam-in-block engines. The system incorporates a vane-type camshaft phaser that changes the angular orientation of the camshaft, thereby adjusting the timing of the intake and exhaust valves to optimize performance and economy, and helping lower emissions. It offers infinitely variable valve timing in relation to the crankshaft. The cam phasing creates ?dual equal? valve timing adjustments. In other words, the intake valves and exhaust valves are varied at the same time and at the same rate. The cam phaser vane is attached to the camshaft on the front journal ? a technique made easier by the award-winning ?assembled-camshaft? design pioneered by General Motors. With this design, separate camshaft lobes are installed on a hollow camshaft tube rather than the traditional method of grinding a camshaft from a single piece of stock. The cam position sensor reads a new cam target ring, with four segments that increases the accuracy of the position readings. Hydraulic roller lifters actuate the valves via pushrods.
Variable intake manifold
The variable intake manifold is an engine feature usually found only on high-cost, premium European performance cars, but the new manifold design is standard with the 3.9L V-6. The active air intake optimizes incoming airflow through a valve in the intake manifold. The valve creates longer or shorter intake tracts that correspond to desired engine-performance parameters. At low engine speeds, the valve creates a longer path for intake air, enhancing combustion efficiency and torque output. At higher engine speeds, the valve opens, creating a shorter air path for maximum power production.
?U?-flow cooland design
The coolant passages in the 3.9L V-6 are designed to flow coolant in a predetermined path. The coolant enters the accessory drive end of the engine block from the radiator, then flows to the transmission end of the engine. From there it flows up to the cylinder heads, and back to the accessory drive end of the engine. The thermostat is placed near the inlet from the radiator, promoting quickest possible warm-up, and the fill point is at the highest point of the cooling system to prevent air from being trapped in the system.
Shrouded injectors and returnless fuel system
New-generation fuel injectors with shrouded nozzles are designed to minimize clogging and work better with hot fuel.
Electronic throttle control
The 3.9L V-6 features electronic throttle control. With ETC, there is no mechanical link between the accelerator pedal and the throttle. A potentiometer at the gas pedal measures pedal angle and sends a signal to the throttle actuator controller (TAC) module, which is integrated into the throttle body and passes the signal to the powertrain control module (PCM). The PCM then directs an electric motor to open the throttle at the appropriate rate. ETC delivers a number of benefits to the customer. It uses several data sources, including the transmission's shift patterns and traction at the drive wheels, in determining how far to open the throttle. ETC delivers outstanding throttle response and greater reliability than a mechanical throttle. Cruise control functions are integrated into the throttle control, reducing the number of engine parts and simplifying assembly.
Advanced direct ignition and new engine control module
The crankshaft position is sensed by the 58X Quick Sync system, which uses 58 sensors to determine position, and increase ignition accuracy. The 3.9L?s advanced technology is enabled by the new E67 engine control module (ECM), which uses a 32-bit processor and is part of GM?s new family of control modules run on proprietary GM-developed software. The E67 handles the advanced computing needs of the variable valve timing, as well as the advanced direct ignition and electronic throttle control.
Piston-cooling oil jets
To cool the pistons and ensure even lubrication of the cylinder walls, each cylinder has an oil jet that sprays the bottom side of the piston with oil.
Low maintenance
The spark plugs are iridium-tipped and rated for 100,000 miles, as is the coolant. The GM Oil Life System (GMOLS) measures how hard the engine is used and calculates the optimal life expectancy of the engine oil, which can reduce the number of oil changes the
engine requires during its lifetime. An indicator on the instrument panel illuminates when the oil needs to be changed.
Overview
The 3900 3.9L V-6 is part of an all-new family of sophisticated overhead valve 60-degree V-6 engines that are economical to produce but also incorporate advanced technologies like variable valve timing and a variable intake manifold to generate very competitive specific horsepower and torque outputs. Introduced in the Pontiac G6 GTP, the 3.9L V-6 is the first version of the new family of V-6 engines. Leading technology is used in the valvetrain and ignition to increase efficiency and ensure lower fuel consumption. In addition, emissions are lower at every rpm level due to the same high technology. Durability and low maintenance are also notable features.
For 2006, the new 3.9L delivers between 235 and 240 horsepower and 239 and 242 lb.-ft. of torque, depending on vehicle application.
The 3.9L V-6 shares 80 percent of its components with the new 3.5L V-6 (LZ4).
The 60-degree angle between cylinder banks is naturally balanced for a V-6 engine, which requires no balance shafts to cancel out second-order harmonic vibrations. The cylinders are offset, meaning the centerline of the cylinders points to an intersection slightly lower than the centerline of the crankshaft. This was designed to make room for larger cam bearings, and make room for the large bores of the engine. The cylinder bores are the same diameter as those in the LS1 small-block V-8 engine.
A new cast aluminum oil pan increases rigidity of the engine and dampens engine noise. The timing chain from the cam uses a leaf-type tensioner, which reduces noise and vibration.
The intake manifold is a two-piece cast aluminum component, which is cast in a semi-permanent mold to increase strength. Multi-layer steel gaskets are sandwiched between the block and cylinder heads, increasing long-term durability. An acoustic engine cover reduces the amount of noise transmitted to the passenger compartment from the engine.
Like the cylinder bore size, the valves are similar to those in the LS1 small-block V-8, too. Combustion chamber design follows the characteristics that emerged during the development of the high-output LS1 and LS6 small block V-8 engines. Combined with the sophisticated variable valve timing, this contributes to smooth, even torque output at all rpm ranges.

[blackbombshell95]

drools

[bszopi]

Unfortunately Chris, that's for the OTHER 3500. Yes, there are actually different versions of the 3500. There is the 3500 similar to the 3400 (the LX9) which is what this thread is about. Then there is the one similar to the 3900 (the LZ4 and LZE), which is what that info is about. So the LX9 still shares the same block as the 3100 and 3400. I know, GM is making it more confusing for us now...

[Doubt_Incarnate]

at last, we now have a "small block" and a "big block" for the 660

[Nightingale]

There is also the I5 in the colorado that is labled I5 3500 rather then 3.5L (definitely a very nice motor though for being an inline 5).

[Froggx]

I would love to get my hands one on of these "big block" 660's. Sharing characteristics with the LS1 design it's going to be one sick performer. With how well our current motors take to boost I'd love to throw a turbo onto one of these. Just need to give us an aluminum block now

[bszopi]

Hey Colin, since you are on right now... Can you get some pics of the cam? I want to see if it changed any.

Also, looking at the 2006 Powertrain lineup, the 3100 and 3400, with the exception of the truck 3400 (Equinox and new Pontiac) are no more. All that remains is the new 3500s (both the standard and VVT ones) and the 3900. With what we have seen so far, just wondering if ANY of the recent products are going to work on the new engines...

[v6h.o.]

Yeah Brad, I've been meaning to do that. Was away all weekend, Just got back. I'll try and take some pics of the cam this week.

[GinoBeats]

Guess what we're doing today? A brand new '05 with 8 miles on it, re and re 3500 engine assembly