Flashback: Inside Holden’s Alloytec V6

We take a look inside Holden’s all-alloy, quad-cam, 24-valve, 190kW V6, released with the VZ Commodore

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Photographers: Holden

First published in the October 2004 issue of Street Machine

Go to: Alloytec V6 in detail | History of the Holden six

Holden released the new VZ Commodore with a brand new, high-tech, 3.6-litre, 60degree V6 engine. Dubbed the Alloytec, available in either 175kW or 190kW formats.

The Alloytec V6 is a local variant of a new, clean-sheet, global V6 developed by a consortium of US, European and Australian General Motors engineers over the past five years and dubbed the GM High Feature Engine (or HFV6). It is produced at two locations (Melbourne and Canada) for a worldwide market. The Melbourne plant has been operational since November last year, supplying engines for Mexican-built, front wheel-drive Buicks. From June, production has also included rear-wheel-drive Commodore-spec mills. Annual production (domestic and export) is tipped to exceed 175,000 units by 2005; total factory capacity is a staggering 240,000 engines a year, or 900 per day.

The components are mostly sourced from overseas and imported in rough cast form. Significant machining operations are conducted prior to final assembly. This compares with the Ecotec V6 which was better described as an overseas engine imported in CKD (completely knocked down) form and assembled here only.

Let’s have a look at the Alloytec in detail:

Cylinder block, heads, valvetrain

The deep-skirt alloy cylinder block is cast in 319 aluminium with cast-iron cylinder liners, uses six-bolt main bearing caps, and is around 10kg lighter than the 3.8-litre, cast-iron Ecotec block.

DOHC, four-valves-per-cylinder heads are cast from the same alloy and sit on multi-layer, stainless steel head gaskets. Valvetrain is a friction-friendly roller-follower design, with hydraulic lash adjustment. Cams are driven by three separate chains, rather than the more normal single belt set-up. Weight savings from the switch to alloy are offset by the much larger castings containing two camshafts per bank, so that total engine weights are similar.

The seriously trick bit is an electronically-controlled, hydraulically-actuated, continuously variable valve timing system — inlet cams only on the 175kW cooker; inlet and exhaust cams on the 190kW hottie. Cams are variable through 50 degrees relative to the crankshaft.

In layman’s terms, the cam timing can replicate what we’d call a mild, short duration cam profile, for smooth idling and tootling around town, by retarding the timing of the inlet cam; then, by advancing the inlet cam, the system can replicate the cam profile of a long duration hottie on the pace.

The real advantage of variable exhaust cams lies in improving emissions and fuel economy by more accurately determining the desired amount of exhaust gas recirculation back into the combustion chamber.

Fuel and spark

But there’s more! The 190kW engine also features a dual-stage variable intake manifold (VIM). An electronically-operated valve within the manifold divides the plenum to change its volume according to engine demands.

When the VIM valve is shut, the cylinders are fed from two separate (smaller) plenums, which boosts cylinder charging at engine speeds below 4000rpm. Then, at higher speeds, the VIM valve opens and all cylinders feed from a single, twice-as-big plenum, boosting volumetric efficiency at high engine speeds.

The 68mm throttle is controlled by the engine control unit (rather than by a cable), programmed for maximum torque. Fuel delivery is sequential port fuel injection on a returnless system.

Coil-on-plug ignition (one coil per cylinder, like the LS1, which mounts them on the rocker covers) fires trick, extended-life spark plugs, which have a service life of 120,000km — something to do with accessing the bastards on the high-cam heads and a pain if your old-school tuning repertoire includes reading and swapping plugs.

Lubrication and cooling

Pressure-actuated oil jets aimed at the underside of each piston cool the slugs, allowing the engineers to seek more power. Yes, in a Holden six — how trick is that! The 6.5-litre oil pan incorporates a windage tray and is a structural member of the power train. The spin-on oil filter is a thing of the past with a new, replaceable, cartridge-style filter doing the job.

The cooling system is pretty much like every other cooling system, apart from the thermostat monitoring inlet flow. There’s also a failsafe system which, in the “unlikely event of overheating” (to quote Holden), operates the engine on alternating pairs of three cylinders, allowing you to limp home or to a servo without totally cooking your donk.

Future potential

While we get the 3.6-litre, normally aspirated version, Holden will manufacture 2.8-litre and 3.2-litre variants, both in rear-wheel (north-south) and front-wheel-drive (east-west) for overseas markets. The engine architecture has already been designed to include, in future years, spark-ignition direct injection (whatever that means), and turbocharging.

Will these new motors fit the early-girl Holdens? No reason why not, and with 190kW available bog stock and a torque curve as flat as the Hay Plains, we predict they’ll be the motor of choice for retrotech engine swaps. And we haven’t even starting talking about the new six-speed manuals and five-speed autos, which are also part of the new VZ Commodore. Bring it on!

Holden Alloytec V6 in detail:

1. Brand new five-speed auto, also used in BMW 3-series and X5, features Active Select for drivers “who wish to take more direct control”. Extra smarts in the transmission control system evaluate driving conditions and driver inputs through Shift Stabilisation and Performance Algorithm Liftfoot (PAL) software functions. Transmission will allow shifts up to 6500rpm.

2. Both versions of the Alloytec donk cop Variable Cam Phasing — cooker only gets it on the intake, while the hottie scores a variable exhaust cam too. This gives a smooth-idling engine around town but once the boot goes in, the engine can really breathe all the way to the redline.

3. Variable Intake Manifold valve on Alloytec 190. Below 4000rpm the valve partitions the plenum, creating two small chambers for better low-end performance. Above that, the valve opens, creating a large, single plenum. According to Holden this “boosts ram cylinder charging volumetric efficiency at high speeds, for increased power.”

4. It’s easy to see the straight run the intake charge gets from the manifold, through the cylinder, and out the exhaust. Flat top pistons feature four valve reliefs. Engine runs 10.2:1 compression and all performance figures are quoted using 91 RON fuel. Use the good stuff and you can expect better performance and economy.

5. Coil-on-plug ignition system helps deliver maximum spark energy and very precise timing. With fewer parts and no high-tension leads, quality, reliability and dependability are improved.

6. Inset is the engine-mounted 32-bit Bosch Motronic ME9 ECU. Micro-hybrid design means the unit is small, and strong enough to be engine mounted, which frees up space in the and eliminates attachment problems. The ECU can withstand 110C temps and 30G vibration. Electronic Throttle Control (ETC, main pic) eliminates the cable between the accelerator pedal and throttle body. Holden says ETC “coordinates a driver’s intentions with the actions of the various control components”. In other words, it knows what you want.

7. From here you can see the compact design of the 60degree V6. Should slot right into an early engine bay.

8. New cartridge-style oil filter replaces traditional spin-on type. Easier to replace and more environmentally friendly.

9. New deep-skirt block is cast in 319 aluminium with cast-iron cylinder liners. Fully machined, the block weighs a trim 32kg.

10. (Left) The four-valve, DOHC heads are also cast in 319 aluminium and use multi-layer, stainless steel gaskets. Each head weighs 12kg, machined.
(Right) Pressure-actuated piston oil jets help cool the underside of the pistons to allow higher power and durability. It also reduces noise from piston contact with the cylinder bore and from the piston wrist pin.

11. Staff at the new Global V6 engine plant in Port Melbourne work so fast our cameras couldn’t capture them! The plant cost $400 million and at full tilt can pump out 900 engines a day, or 240,000 a year.

12. When the parts from each assembly line are completed, they’re slotted together. Each engine typically takes 3.5 hours to be assembled and weighs around 168kg complete.

13. This sexy looking bit of gear is the aluminium piston and sinter-forged steel conrod. This combination offers durability, strength and a low reciprocating mass.

Holden Alloytec 190 specs

Engine style:60degree V6
Capacity:3564cc
Bore x stroke:94mm x 85.6mm
Claimed power:190kW (255hp)@6500rpm
Claimed torque:340Nm@3200rpm
Comp ratio:10.2:1
Fuel:Regular unleaded (91 RON)

History of the Holden six

1948: Six-cylinder, 132ci (2.15-litre), 60hp (45kW) Grey engine commences production, to power the Holden 48-215 (later dubbed the FX);

1963: Upgraded Red six commences production to power the EH. Two capacities offered: 149ci (2.45 litre) in low and high-compression versions, and the big 179ci (2.95-litre) with a heady 115hp (86kW);

1964: 179ci X2 with twin carbs, hot cam and sports exhaust boasts 141hp (105kW) and is optional on the HD;

1967: Capacity of Red sixes upped to 161ci (2.65-litre) and 186ci (3.05-litre) for the HR. Twin-carb 186 X2 now makes 145hp (108kW). Twin carbs dropped for a single twin-barrel carb, now dubbed the 186S;

1969: The LC GTR was released, using the 161S motor, rated at 125hp and running a single Bendix-Stromberg WW2 downdraught carbie

1970: The LC GTR XU-1 Torana was released was released with a hottie 186, complete with triple Stromberg 150CDS side-draught carbs, rated at 160hp

1971: Introduction of the HQ sees capacity of the Red six blow out to 173ci (2.84-litre) and 202ci (3.3-litre);

1972: The LJ GTR XU-1 grew to 202 cubes and ran triple Stromberg CD-175 carbies, rated at 190hp;

1980: Blue sixes in VC Commodores retain capacity but feature new 12-port head, two-barrel carb and electronic ignition;

1984: 173 cuber dropped and fuel injection added to the 202 in the VK range. Claimed power of 142hp (106kW) recalls earlier glory days;

1985: Holden pushrod six dies after 38 years of continuous production, replaced for one model only (VL) by 3.0-litre Nissan straight six in normally aspirated and turbocharged forms, the latter offering a serious 201hp (150kW);

1988: 3.8-litre Buick V6 is assembled in Melbourne for fitment to VN Commodores. 170hp (127kW) in a lightweight shell makes the VN a legend, one that many teens still aspire to today;

1995: Revised Ecotec V6 is smaller, lighter and even more fuel efficient than the miserly Buick. Power gets kicked up to 197hp (147kW);

1996: 221hp (165kW) supercharged Ecotec V6 commences production, upgraded to 229hp (171kW) for the VT the following year;

2004: All-new Global Alloytec V6 is released with VZ Commodores.

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