New HSV muscle engines

Any power advantage Ford Performance Vehicles will gain via its new FG-based 300kW-plus models appears likely to be short-lived as the GM world is opening its skunkworks' doors to provide several amazing new V8 choices open to Holden Special Vehicles.

The missing links in HSV's comprehensive new engine strategy have been progressively revealed in Detroit over recent months.

Speculation over the full-house dry-sumped LS7 engine has distracted local performance fans from the true extent of the changes across the whole HSV range due over the next 18 months; not all of which will be revealed at this week's Melbourne International Motor Show.

The Carsales Network can now reveal the extent of the generational change about to take place at HSV. Thanks in part to insiders at the Lion's go-fast outfit, we've been able to piece together the likely powertrain strategy.

LS3
This is the new entry Corvette engine that replaced the LS2 6.0-litre base engine introduced locally in the Z-series HSV range then carried over into the current E-series range. Its lift in capacity to 6.2-litres will bring a power boost in the HSV context from the current 307kW to over 320kW with a corresponding increase in torque. Depending on exhaust system, it could be as high as 575Nm.

It is not a case of if this is going to happen, it's when, as US production of the LS2 ceased almost a year ago.

Anticipating this, HSV stockpiled what it thought would be enough LS2 engines to avoid such a significant engine change so soon after the E-series range went on sale. However, record HSV sales have left this stockpile depleted far earlier than expected.

Although the LS3 range may not be previewed at the Melbourne motor show this week, HSV will be forced to make the switch to the bigger LS3 engine by around the same time as FPV's new FG range goes on sale in June.

There is also the possibility that the additional hardware and HSV-specific software required to activate the variable displacement feature of this engine will also be ready.

LS9
This is the new and very expensive supercharged version of the 7.0-litre LS7 engine except capacity has been reduced to the 6.2-litres of the LS3 engine to deliver a block with enough meat left in it to contain the extra stresses imposed by forced induction. It was developed specifically for the Corvette and therefore has the dry-sump lubrication and intercooler design tailored to the US sportscar's engine bay.

Like the atmo LS7, the LS9 has titanium connecting rods and inlet valves, sodium filled exhaust valves, forged pistons, stainless steel exhaust headers and special steel main bearing caps. It also has a beefed-up block, 12mm head bolts and a multi-layer head gasket.

Its Eaton twin-rotor supercharger has a high 2.3-litre blower capacity with four lobe rotors and a boost pressure of 10.5psi. Fuel pressure is boosted to 600kPa  to match. Its air-to-liquid intercooler system consists of twin heat exchangers divided on either side of the supercharger to exploit the Corvette's low but wide engine bay.

Because the LS9 is specifically tailored to the Corvette architecture, it presents many installation challenges for HSV with its duplicated intercooler plumbing that spreads sideways over both cylinder heads. This is in addition to the dry-sump LS7 lubrication system.

Although it delivers strong power and torque figures, it has a very different character to the raw, peaky, race-bred feel to the LS7.

The business case to commence a new development program for an HSV model based on this engine is still not clear cut when its massive 460kW and torque appproaching 800Nm would add another dimension to potential driveline, suspension and chassis stresses.

This would add at least another 18 months development, stretch pricing expectations even further and fundamentally duplicates what would be achieved by the LS7; already well down its local development path.

There are also indications that the new Camaro will be launched with a variation of this engine. Imported duty-free from the US as a factory-built vehicle, such a Camaro would undermine a top-shelf HSV LS9 version on performance and certainly on price.

LSA
This is the missing link ready to transform several HSV models and is the luxury passenger car version of the LS9 as previewed for the 2009 Cadillac CTS-V.

Re-engineered for refinement as much as performance, the LSA is a perfect fit for HSV's Senator and Grange ranges as a premium engine option matched to a six-speed auto.
If the Cadillac CTS-V won't reach here because of RHD issues, then it makes sense for HSV to fill the gap.

The LSA engine has a single intercooler made possible by the Cadillac's longer and taller passenger car engine bay which makes the engine slightly taller than the LS9 but more efficient. Although the Eaton supercharger is similar, its capacity is cut to 1.9-litres and boost pressure is dropped back to 9.0psi with a reduced 450kPa fuel pressure to match.

To cut costs and in deference to the lower internal stresses, the titanium internals are replaced with cheaper steel or iron items. The exhaust manifolds revert to cast iron, as much for refinement as cost, and the main bearing caps are iron. Pistons are cast aluminium. However, the 6.2-litre special block, head gasket and dry sump lubrication remain.

Those who have driven this engine comment on its constant shove from quite low revs and its amazing refinement as you would expect from its 410kW and 745Nm.

In other words, it is not an edgy GTS-R engine but it would transform the big luxury Senator and Grange models with fewer installation problems and a much lower option cost than the LS9.

A bonnet bulge would look after the simpler single intercooler installation leaving HSV to exploit the dry sump installation work already completed for the LS7. The automatic is an added bonus.

Ensuring that every aspect of the VE platform and driveline can handle such a big torque increase plus bonnet changes dictated by the intercooler installation mean that any showroom appearance is at least 18 months away.

The other option believed to be under consideration is a softer and cheaper wet-sumped version of the LSA that could be installed on the Holden production line and shared with the Camaro. Such an engine has yet to surface.

LS7
There are those within HSV and Holden who want a hero low-volume GTS-R powered by this 7.0-litre dry-sumped atmo monster more than ever. Now that the Camaro is a certainty for Australia with premium models likely to be powered by the variation of the LS9 or LSA, the LS7 has assumed higher priority.

It also won't be undermined by a Camaro version, especially now that HSV has finally conquered the dry sump installation problems and it is virtually ready to roll.

Those who have driven an LS7-powered HSV note that it feels relatively soft under 4000rpm then transforms into a hard-edged racecar engine as the revs rise. This engine is best experienced as a manual, in a tight, minimal weight package. Its 377kW/637Nm on paper figures will never match the supercharged LSA or LS9, but that is not what this engine is about.

It is believed that new Pontiac G8 exports have also brought this combination back into the spotlight, especially when a similar version of the G8 has already been shown in the US.

CN reported last year that the installation of the dry sump engine would not be allowed to disrupt the Holden production line which is now flat out meeting new export orders. At the same time, HSV sources noted that this was not a problem when HSV's Clayton facility could easily handle such an installation for a low-volume model.

However, such a post-assembly process may only be required for an interim period if Pontiac also requires an LS7 version of the G8, at which point HSV could piggy-back on the export version -- as it did with its LS2-powered GTO based on Pontiac's version of the Monaro.

Because this vehicle is furthest down the development track, our sources tell us this is the model that Melbourne motor show visitors are most likely to see.