GM V6 geneology questions...

I believe it is based in the 2.8/3.1/3.4 lineage, but with the various bugs fixed (hopefully). I had a late 80s 2.8 in the past that was pretty much indestructible. I've had a couple of modern 3.1s that were the opposite :)

It's an enlarged 3.5.

2.8/3.1/3.4?

No the 3.5 basic design goes back to 1955 to the 265CI V8 which became the

283, then the 307 to the 350. Then later 2 of the cylinders were removed the engine was turned sideways and viola! You have a 3.5 V6!

Nope, that was the 4.3 - I'd be curious to get the straight scoop on the 3.5 myself.

nate

The 200ci (around 3.3L) and the 229ci (around 3.8L) are also in the same line as the 4.3 liter or 262ci.

The 3.5 liter engine according to a couple of web pages I just read was an all new design. Makes sense since it's a dual overhead cam motor.

Taken from the page below.

(quote)

"Ward?s, publisher of Ward?s Auto World and Ward?s Engine and Vehicle Technology Update, cited GM?s all new 3.5 liter Twin Cam V6 and the gutsy 5.7 liter LS1 Corvette V8 as among the world?s best engines for

1999."

...Ron

--

68' Camaro RS 88' Firebird Formula 00' Mustang GT Vert

That's the 3.5L DOHC "ShortStar" used in late 90s early 00s Oldsmobile vehicles. The new 3.5 and 3.9 the OP is speaking of is the new variable valve timing 60° pushrod V6 line. Or at least that's what I believe he is speaking of.

Here's some cut-and-paste:

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.

The 3.9L V-6 is produced in Tonawanda, New York.

You are confusing the 3.4/3.5 engines with the 3.8 liter engines.

The 3.4/3.5 are 60 degree angle motors (proper for a V-6) which have little or nothing in common with 90 degree bank angle V-8s.

John

Yep, that is what I was speaking of. Thanks for the info.

How does the 3.9/3900 compare with the 3.8/3800 series v6

Doesn't. The 3.8 is a 90° V6.

If, by your question, you mean "which is better?", it is way too early to know.

If you mean "how do they compare design-wise?" there is no comparison other than that they both have six cylinders in a "V" configuration, and have pushrods. The 3800 is a 90 degree iron block with iron heads and is based on a Buick V8 from the 50's or 60's. It was first used in '61 Buick Specials in its original rough-running uneven firing form. Over they years, it evolved from a really bad engine to a pretty good one as a splayed crankpin crank, balance shaft, and other improvements were added.

The 3900 is aluminum and has a 60 degree block. For a pushrod design, it is truly high tech with its variable valve timing, et. al. I presume it is smooth and has good powere, but time will tell how reliable it is.

It's not an all aluminum engine, it has a cast iron block and aluminum heads. Like all the 60 degree v-6's.

Ian