Saab LS2 Specifications
| Engine Model: Saab LS2 |
| Engine Type: 4-cycle 8-cylinder OHV 16-valve liquid-cooled gasoline |
| Total Displacement: 180.5 cu.in (2.95 L) |
| Rated Engine Power: 390-395 Hp (291-295 kW) at 6000 rpm |
| Fuel System Type: Multi-port electronic fuel injection |
____________________________________________________________________________________
The Saab LS2 is a 6.0-liter naturally aspirated V8
engine sourced from General Motors’ Generation IV Small Block engine family,
installed exclusively in the Saab 9-7X Aero SUV for the 2008 and 2009 model
years. This powerplant represented a radical departure from Saab’s traditional
engine offerings, which had been dominated by turbocharged inline-four and
six-cylinder configurations. The LS2 delivered the highest output of any
production Saab vehicle, with 291-295 kW (390-395 hp) and 542 Nm (400 lb-ft) of
torque, transforming the body-on-frame 9-7X into a high-performance sport
utility vehicle that shared its platform and powertrain with the Chevrolet
Trailblazer SS.
The LS2’s architecture adhered to the Small Block design philosophy that had
defined Chevrolet V8 engines for decades: overhead valve (OHV) pushrod
valvetrain, deep-skirt cast aluminum cylinder block, and compact dimensions
relative to its displacement. The all-aluminum construction reduced engine mass
significantly compared to iron-block V8s, contributing to the 9-7X Aero’s weight
distribution and handling characteristics. The engine incorporated high-flow
cylinder heads derived from the Corvette Z06 LS6, cathedral-port intake runners,
and cross-bolted main bearing caps for structural rigidity.
In Saab’s application, the LS2 was calibrated through the GM E40 or E38 engine
control module with Saab-specific tuning integrated with the vehicle’s
StabiliTrak traction control system and electronic throttle control. Despite its
departure from Saab’s traditional engine engineering, the LS2 brought a
reputation for mechanical simplicity, durability, and effortless torque delivery
that distinguished the 9-7X Aero as a unique offering in Saab’s final production
years.
The LS2 is a four-stroke, water-cooled, naturally aspirated gasoline engine
configured for longitudinal mounting in rear-wheel-drive and four-wheel-drive
vehicle architectures. The engine utilizes the Generation IV Small Block
architecture with aluminum block and cylinder head construction.
Engine Type: 90° V8, 4-cycle, water-cooled, naturally aspirated.
Displacement: 5,967 cc (364.1 cu.in).
Bore: 101.6 mm (4.00 in).
Stroke: 92.0 mm (3.62 in).
Compression Ratio: 10.9:1.
Firing Order: 1-8-7-2-6-5-4-3.
Valvetrain: OHV, 16-valve (2 valves per cylinder) with hydraulic roller lifters.
Maximum Power: 291-295 kW (390-395 hp) at 6,000 rpm.
Maximum Torque: 542 Nm (400 lb-ft) at 4,000 rpm.
Redline: 6,500 rpm.
Engine Management: GM E40 or E38 ECM with Saab calibration.
Bore Center Distance: 111.8 mm (4.40 in).
The cylinder block is manufactured from cast aluminum
alloy using a permanent mold casting process with cast-in-place iron cylinder
liners. The aluminum construction reduces engine mass by approximately 45 kg
(100 lb) compared to iron-block V8s of similar displacement while maintaining
the rigidity required for high-performance operation.
The block features a deep-skirt design where the casting extends below the
crankshaft centerline, with the main bearing caps recessed into the skirt
structure. This configuration provides exceptional lateral stiffness and
minimizes crankshaft bearing bore distortion under high cylinder pressures. A
distinguishing feature of the LS2 block is the cross-bolted main bearing cap
arrangement. Each of the five main bearing caps is secured with vertical bolts
through the cap into the block and additional horizontal cross-bolts through the
external side of the block into the cap ends, providing a rigid support
structure for the crankshaft.
The cylinder bores utilize pressed-in, thin-wall iron liners that are machined
with a plateau-honed finish after installation. The block incorporates siamesed
bore architecture where adjacent cylinders share common walls, increasing
structural rigidity and reducing overall block length. Water jackets surround
each cylinder bore with coolant flow directed from the water pump into the block
before rising into the cylinder heads. The block includes provisions for the
piston cooling oil jets, which direct a continuous stream of oil to the
underside of each piston crown.
Block Material: Cast aluminum alloy with cast iron cylinder liners
Bore Diameter: 101.6 mm (4.00 in)
Cylinder Bank Angle: 90 degrees
Main Bearing Quantity: 5
Main Bearing Cap Design: Cast iron, four-bolt with cross-bolts
Piston Cooling: Oil jets directed at piston undercrowns
The cylinder heads are constructed from cast aluminum
alloy using a permanent mold casting process, with separate heads for each
cylinder bank. The LS2 utilizes high-flow cylinder head castings derived from
the LS6 engine used in the Corvette Z06, featuring cathedral-shaped intake ports
optimized for high airflow at elevated engine speeds.
The OHV valvetrain operates 16 valves - two per cylinder - through a pushrod
arrangement. The camshaft is located within the engine block’s cam bore, with
hydraulic roller lifters following the cam lobes. Pushrods transmit motion from
the lifters to the rocker arms, which actuate the valves. This configuration
reduces the engine’s overall height and width compared to overhead camshaft
designs while concentrating reciprocating mass lower in the engine for a reduced
center of gravity.
The cylinder heads incorporate 67.5 cc combustion chambers with a pent-roof
design and centrally located spark plugs. The intake ports are of the
cathedral-port configuration, measuring approximately 210-220 cc in volume, with
the intake valves positioned at a 15-degree angle relative to the cylinder bore
centerline. The exhaust ports are of the D-shape design optimized for exhaust
flow. Valve seats are pressed-in inserts of sintered iron for intake valves and
nickel-based alloy for exhaust valves.
The valvetrain incorporates roller-type rocker arms with a 1.7:1 ratio, mounted
on pedestals integral to the cylinder head casting. Hydraulic roller lifters
provide automatic valve lash adjustment, eliminating the need for periodic valve
clearance adjustments. The camshaft is supported in five bearing journals
machined directly into the cylinder block.
Head Material: Cast aluminum alloy
Valve Configuration: OHV, 16-valve with hydraulic roller lifters
Intake Valve Diameter: 50.8 mm (2.00 in)
Exhaust Valve Diameter: 39.4 mm (1.55 in)
Valve Stem Diameter: 8.0 mm (0.31 in) intake; 8.0 mm (0.31 in) exhaust
Valve Seat Angle: 45 degrees
Rocker Arm Ratio: 1.7:1
Camshaft Drive: Gear-driven from crankshaft via timing chain
Hydraulic Lifters: Yes, roller-type
The fuel system employs sequential multi-port
electronic fuel injection (SFI) with individual injectors positioned in the
intake manifold runners. The system operates in closed-loop fuel control using
feedback from heated oxygen sensors mounted in the exhaust system.
An in-tank electric fuel pump supplies fuel to the engine at regulated pressure.
The fuel pressure regulator is mounted on the fuel rail or integrated with the
fuel pump module, maintaining constant pressure relative to intake manifold
vacuum. The injectors are of the saturated-switch type with high impedance,
permitting direct drive from the engine control module.
The engine control module calculates injector pulse width based on inputs from
the mass air flow (MAF) sensor, crankshaft position sensor, camshaft position
sensor, throttle position sensor, coolant temperature sensor, intake air
temperature sensor, and oxygen sensors. The system operates in closed-loop fuel
control during steady-state conditions, maintaining stoichiometric air-fuel
ratio for optimal catalytic converter efficiency.
Injection Type: Sequential multi-port fuel injection (SFI)
Fuel Pressure: 380-420 kPa (55-61 psi) with vacuum line disconnected
Injector Resistance: 12-15 Ohms
Fuel Requirement: 91 octane (RON) premium unleaded minimum; 95 octane (RON)
The lubrication system is a fully pressurized, wet-sump
design with a gear-type oil pump mounted internally at the front of the engine
and driven directly by the crankshaft. The oil pump utilizes a pair of meshing
gears to generate flow with positive displacement characteristics.
Oil is drawn from the cast aluminum oil pan through a mesh strainer positioned
at the sump’s lowest point. Pressurized oil passes through a full-flow,
replaceable oil filter mounted externally on the cylinder block. The filter
incorporates an anti-drainback valve to maintain gallery priming during engine
shutdown. From the filter, oil enters the main oil gallery cast through the
cylinder block, supplying the crankshaft main bearings, connecting rod bearings,
camshaft bearings, hydraulic roller lifters, and rocker arm assemblies.
Piston cooling jets are mounted in the cylinder block and direct a continuous
stream of oil to the underside of each piston crown, managing thermal loads
under high-output conditions. The oiling system is designed to maintain
consistent pressure during sustained high-rpm operation. An oil cooler - a
water-to-oil heat exchanger - is mounted on the cylinder block adjacent to the
oil filter on vehicles equipped for towing or performance applications.
Oil Type: Full synthetic 5W-30 meeting GM dexos1 specification
Oil Capacity (with filter): 5.7-6.2 L (6.0-6.5 US qt)
Oil Pressure (at idle, warm): 200-250 kPa (29-36 psi)
Oil Pressure (at 3,000 rpm): 350-450 kPa (51-65 psi)
Oil Pump Type: Gear-type, crankshaft-driven
Oil Cooler: Water-to-oil heat exchanger on select applications
Piston Cooling: Oil jets directed at piston undercrowns
The cooling system is a pressurized, liquid-cooled
design with a belt-driven centrifugal water pump mounted on the front of the
engine. The water pump impeller circulates coolant through the cylinder block
water jackets, cylinder head passages, heater core, and radiator. The system is
sized to accommodate the thermal demands of the 6.0-liter V8 under sustained
high-load operation.
A wax-pellet thermostat mounted in a housing on the water pump inlet regulates
coolant flow to the radiator. The thermostat begins opening at a calibrated
temperature and achieves full opening within a defined temperature range. A
bypass circuit permits coolant circulation within the engine during warm-up,
bypassing the radiator until the thermostat opens.
The radiator is a cross-flow aluminum-plastic construction with a
high-efficiency multi-louvered core sized for the V8 configuration. An electric
cooling fan or engine-driven fan with viscous clutch provides forced airflow
through the radiator and condenser, with fan operation managed by the engine
control module based on coolant temperature, vehicle speed, and air conditioning
system demand.
Coolant Type: Ethylene-glycol based antifreeze meeting GM specification
Coolant Capacity: 12.5-14.0 L (13.2-14.8 US qt) depending on radiator
configuration
Thermostat Opening Temperature: 86-90 °C (187-194 °F)
Thermostat Full Opening Temperature: 100 °C (212 °F)
Radiator Cap Pressure: 110-140 kPa (16-20 psi)
Water Pump Type: Centrifugal, belt-driven
| Intake and Exhaust Systems |
Intake System: The intake system incorporates a
paper-element air cleaner with an integrated resonator. Filtered air passes
through a mass air flow (MAF) sensor before entering the electronic throttle
body. The throttle body houses an electronically controlled butterfly valve
(drive-by-wire) with no mechanical cable connection to the accelerator pedal.
The intake manifold is a composite plastic or cast aluminum design with
equal-length runners and a large-volume plenum chamber optimized for high-rpm
power delivery.
Exhaust System: The exhaust system utilizes stainless steel tubular exhaust
manifolds with equal-length runners for each cylinder bank. Four heated oxygen
sensors - two per bank - provide feedback to the engine control module, with
pre-catalyst sensors controlling fuel trim and post-catalyst sensors monitoring
converter efficiency. The exhaust system incorporates dual three-way catalytic
converters.
The LS2 employs a distributorless ignition system with
individual coil-near-plug ignition coils mounted on the valve covers, connected
to spark plugs through short spark plug wires. The engine control module
controls ignition timing based on crankshaft position, camshaft position, and
knock sensor feedback. Two knock sensors - one per cylinder bank - allow the ECM
to retard ignition timing independently on each bank under detonation
conditions.
Overall Length: 720 mm (28.3 in)
Overall Width: 860 mm (33.9 in)
Overall Height: 690 mm (27.2 in)
Dry Weight (complete engine): 205 kg (452 lb)
Engine Oil Change: 8,000-12,000 km (5,000-7,500 mi) or
1 year.
Engine Oil Filter Change: At every oil change.
Timing Chain: Inspection for noise and stretch; no scheduled replacement
interval.
Spark Plug Replacement: 160,000 km (100,000 mi) for iridium-tipped plugs.
Spark Plug Type: NGK IFR5T11 or AC Delco 41-110.
Spark Plug Gap: 1.0-1.1 mm (0.039-0.043 in).
Coolant Replacement: 160,000 km (100,000 mi) or 5 years.
Drive Belt (Accessory) Inspection: Every 15,000 km (9,300 mi) for tension,
cracking, and glazing.
Drive Belt Replacement: 80,000 km (50,000 mi).
Air Filter Replacement: 30,000 km (18,600 mi) or as indicated.
Fuel Filter: Integrated with fuel pump assembly; no scheduled replacement.
Valve Clearance Adjustment: Not required due to hydraulic lifters.
Cylinder Head Bolts (M11 x 2.0): 30 Nm (22 lb-ft)
Main Bearing Cap Bolts (Vertical, M14 x 2.0): 30 Nm (22 lb-ft)
Main Bearing Cross-Bolts (M10 x 1.5): 20 Nm (15 lb-ft)
Connecting Rod Cap Bolts (M9 x 1.0): 20 Nm (15 lb-ft)
Camshaft Retaining Plate Bolts (M6 x 1.0): 10-12 Nm (89-106 lb-in)
Intake Manifold Bolts (M8 x 1.25): 10-12 Nm (89-106 lb-in)
Exhaust Manifold Nuts (M8 x 1.25): 20-25 Nm (15-18 lb-ft)
Spark Plugs: 20-25 Nm (15-18 lb-ft)
Oil Pan Bolts (M6 x 1.0): 10-12 Nm (89-106 lb-in)
Water Pump Bolts (M8 x 1.25): 20-25 Nm (15-18 lb-ft)
Crankshaft Pulley Bolt (M20 x 1.5): 150 Nm (111 lb-ft)
Flex Plate / Flywheel Bolts (M11 x 1.5): 50 Nm (37 lb-ft)
The Saab LS2 engine was deployed in a single vehicle
application, representing the flagship performance model within Saab’s final
production range.
Saab 9-7X Aero: 2008-2009 model years. The LS2 was installed exclusively in the
Aero trim level of the Saab 9-7X, a mid-size body-on-frame SUV produced at
General Motors’ Moraine, Ohio assembly plant.
The 9-7X Aero shared its GMT360 platform with the Chevrolet Trailblazer SS, GMC
Envoy Denali, and other GM SUVs, but received Saab-specific tuning for
suspension, steering, and interior appointments. The LS2 in the 9-7X Aero was
calibrated for 291 kW (390 hp) and 542 Nm (400 lb-ft), paired with a four-speed
automatic transmission and all-wheel drive.
The vehicle featured Saab’s center-console ignition placement, unique front and
rear styling, and upgraded interior materials distinguishing it from its GM
platform counterparts. Production of the 9-7X Aero with the LS2 ended with the
discontinuation of the GMT360 platform and the winding down of Saab operations
under General Motors ownership.
____________________________________________________________________________________
| Car Engines Technical Specifications |
| Small Engines Technical Specifications |
| Industrial Engines Technical Specifications |
| Outboard Engines Technical Specifications |
