Saab B234R Specifications
| Engine Model: Saab B234R |
| Engine Type: 4-cycle 4-cylinder DOHC 16-valve turbocharged liquid-cooled gasoline |
| Total Displacement: 139.7 cu.in (2.29 L) |
| Rated Engine Power: 225 Hp (165 kW) at 5500 rpm |
| Fuel System Type: Multi-point electronic fuel injection |
____________________________________________________________________________________
The Saab B234R exemplifies the philosophy of
over-engineering that characterized Saab’s approach to performance engine
development. Its construction centers on a cast iron cylinder block with a
square architecture, utilizing a 90.0 mm bore and 90.0 mm stroke, which
contributes to favorable torque characteristics across a wide engine speed
range.
The valvetrain features a double overhead camshaft (DOHC) configuration with 16
valves, hydraulic lifters for maintenance-free operation, and sodium-filled
exhaust valves to withstand elevated exhaust gas temperatures. The Mitsubishi
TD04HL-15T turbocharger, paired with an aluminum intercooler, provides forced
induction with rapid spool characteristics, delivering peak torque from 1,800
rpm.
The Trionic 5.5 engine management system integrates ignition and fuel control
with a unique ionization sensing capability, allowing the system to detect knock
and misfire through the spark plug electrodes. The internal rotating assembly
possesses exceptional strength, with tuners frequently utilizing the B234R
bottom end for substantially higher power outputs than the factory
configuration. The engine’s torque delivery, particularly in manual transmission
applications, established performance benchmarks that exceeded many contemporary
sports cars in real-world acceleration tests.
Engine Type: Inline 4-cylinder, 4-cycle, water-cooled, turbocharged.
Displacement: 2,290 cc (139.7 cu.in).
Bore x Stroke: 90.0 mm x 90.0 mm (3.54 in x 3.54 in).
Compression Ratio: 9.25:1.
Firing Order: 1-3-4-2.
Maximum Power: 225 hp (165 kW) @ 5,500 rpm for manual transmission.
Maximum Torque (Manual): 342 Nm (252 lb-ft) @ 1,800 rpm.
Maximum Torque (Automatic): 294 Nm (217 lb-ft) @ 1,800 rpm.
Redline: 6,000 rpm with fuel cut at 6,200 rpm.
Idle Speed: 850 ± 50 rpm.
Valvetrain: DOHC, 16 valves. Hydraulic lifters. Sodium-filled exhaust valves.
The cylinder block is constructed from cast iron with a
closed-deck design, providing exceptional structural rigidity and resistance to
cylinder distortion under high boost pressures. The block features a deep-skirt
configuration extending below the crankshaft centerline, contributing to overall
stiffness and reduced noise, vibration, and harshness. Five main bearings
support the crankshaft, each bearing cap secured with two bolts.
The cylinder bores are machined to a 90.0 mm diameter with a hardened wear
surface. The water jacket is designed with generous coolant passages to manage
the thermal loads associated with high-output turbocharged operation. The block
incorporates an integrated oil filter housing and oil cooler mounting interface
on the right-hand side. The engine mounting points are positioned on the front
and sides of the block.
The cylinder head is manufactured from aluminum alloy,
featuring a DOHC configuration with the camshafts supported by five bearings
each. The 16 valves are arranged with four valves per cylinder in a pent-roof
combustion chamber design. Valve actuation is achieved via hydraulic lifters
operating directly from the camshaft lobes, eliminating the need for manual
valve clearance adjustment.
The exhaust valves are filled with metallic sodium, which liquefies at operating
temperature and transfers heat from the valve head to the valve stem, allowing
sustained operation under the elevated exhaust gas temperatures of high-boost
turbocharged conditions. The intake valves are positioned at a narrower angle
than the exhaust valves to promote efficient mixture motion. The camshafts are
driven by a timing chain, with a hydraulic tensioner maintaining consistent
chain tension throughout the engine’s operational life.
The fuel system utilizes multi-point electronic fuel
injection controlled by the Trionic 5.5 engine management system. Individual
fuel injectors are mounted in the intake manifold runners, directed toward the
intake ports. The system operates at a fuel pressure of 3.0 bar (44 psi),
regulated by a vacuum-referenced pressure regulator.
The Trionic system integrates ignition control with fuel delivery, utilizing a
mass airflow sensor, throttle position sensor, coolant temperature sensor, and
knock detection through ionization sensing. The intake manifold is constructed
from aluminum with tuned runner lengths optimized for torque production across
the engine speed range. A high-flow fuel pump mounted in the fuel tank supplies
the required volume for the engine’s output.
The lubrication system is a pressurized, wet-sump
configuration designed to support sustained high-performance operation. A
gear-type oil pump, driven directly by the crankshaft, circulates engine oil
through a full-flow disposable filter and an oil cooler. The oil cooler is of
the water-to-oil type, integrated into the oil filter housing, maintaining oil
temperature within operational limits under high-load conditions.
Oil galleries within the block and cylinder head supply pressurized oil to the
crankshaft main bearings, connecting rod bearings, camshaft bearings, and
hydraulic lifters. The turbocharger receives oil through a dedicated supply line
with a restrictor fitting, with oil returning to the sump via a gravity drain.
Total oil capacity, including the filter and cooler, is 4.5 liters (4.8 qt).
The cooling system is a pressurized, water-cooled
design engineered to manage the thermal output of the high-output turbocharged
engine. A belt-driven water pump circulates coolant through the cylinder block,
cylinder head, turbocharger bearing housing, oil cooler, and radiator. A
wax-type thermostat, beginning to open at 87-92°C (189-198°F), regulates coolant
flow to maintain optimal operating temperatures.
The system utilizes a cross-flow radiator with an electric cooling fan
controlled by the Trionic ECU based on coolant temperature and air conditioning
operation. The intercooler is a separate air-to-air unit mounted forward of the
radiator, constructed with aluminum end tanks for improved durability and heat
dissipation compared to plastic-ended units.
Ignition System: The Trionic 5.5 system utilizes a
direct ignition cassette mounted above the spark plugs, incorporating individual
ignition coils for each cylinder. The cassette integrates the ignition control
module and features ionization detection capability. The system monitors
combustion by applying a bias voltage across the spark plug gap after firing,
detecting the presence of ions to identify knock and misfire conditions.
Timing System: The camshafts are driven by a single-row roller timing chain. A
hydraulic chain tensioner, supplied with engine oil pressure, maintains
consistent tension. The timing chain guides are constructed from wear-resistant
polymer. The chain is designed for the service life of the engine under normal
operating conditions.
Turbocharger System: The Mitsubishi TD04HL-15T turbocharger features a 6 cm2
turbine housing, providing rapid spool characteristics. The compressor is sized
to deliver airflow sufficient for the engine’s power output with a wastegate
actuator controlling maximum boost pressure. Factory boost pressure is regulated
to approximately 0.8-1.0 bar (12-15 psi) under full load conditions.
Intercooler: The air-to-air intercooler features aluminum end tanks, offering
improved heat rejection and durability compared to plastic-ended units. The
intercooler core is sized to reduce charge air temperatures under sustained
high-load operation.
Emission Control: The engine incorporates a closed-loop emission control system
featuring a three-way catalytic converter, exhaust gas recirculation (EGR)
valve, and positive crankcase ventilation (PCV). A heated oxygen sensor mounted
upstream of the catalytic converter provides feedback for closed-loop air-fuel
ratio control.
Electrical System: The charging system consists of a 12-volt, 100-120 amp
alternator. The starter motor is a 1.4 kW (1.9 hp) unit.
Dry Weight: 165 kg (364 lb), including turbocharger and
intercooler plumbing.
Overall Length (from accessory drive to flywheel): 610 mm (24.0 in).
Overall Width: 620 mm (24.4 in).
Overall Height: 690 mm (27.2 in).
Engine Oil Capacity (with filter): 4.5 liters (4.8 qt).
Engine Oil Specification: SAE 5W-30, 5W-40, or 10W-40 meeting API SG or higher.
Engine Oil Pressure (at idle): Minimum 0.8 bar (12 psi).
Engine Oil Pressure (at 3,000 rpm): 3.5-4.5 bar (51-65 psi).
Coolant Capacity: 7.5 liters (7.9 qt).
Coolant Specification: Ethylene glycol-based antifreeze with corrosion
inhibitors.
Spark Plug Type: NGK BCPR7ES or equivalent, gapped to 0.9-1.0 mm (0.035-0.039
in).
Spark Plug Replacement Interval: Every 40,000 km (25,000 miles).
Ignition Timing: Controlled by Trionic ECU; not adjustable.
Valve Clearance: Not adjustable; maintained by hydraulic lifters.
Timing Chain Inspection Interval: Every 100,000 km (62,000 miles) for chain
stretch and guide wear.
Idle Speed: 850 ± 50 rpm, controlled by idle air control valve.
Fuel Pressure: 3.0 bar (44 psi) at idle with vacuum reference disconnected.
Cylinder Head Bolts (M12), Stage 1: 30 Nm (22 lb-ft).
Cylinder Head Bolts (M12), Stage 2: 70 Nm (52 lb-ft).
Cylinder Head Bolts (M12), Stage 3: 100 Nm (74 lb-ft).
Main Bearing Cap Bolts: 65-70 Nm (48-52 lb-ft).
Connecting Rod Cap Bolts: 35-40 Nm (26-30 lb-ft).
Camshaft Bearing Cap Bolts: 20-22 Nm (15-16 lb-ft).
Camshaft Drive Sprocket Bolts: 50-55 Nm (37-41 lb-ft).
Flywheel Bolts: 75-80 Nm (55-59 lb-ft).
Crankshaft Pulley Bolt: 250-270 Nm (184-199 lb-ft).
Intake Manifold Nuts: 20-25 Nm (15-18 lb-ft).
Exhaust Manifold Nuts: 25-30 Nm (18-22 lb-ft).
Turbocharger Mounting Nuts: 35-40 Nm (26-30 lb-ft).
Spark Plugs: 20-25 Nm (15-18 lb-ft).
Oil Pan Bolts: 10-12 Nm (7-9 lb-ft).
Valve Cover Bolts: 8-10 Nm (6-7 lb-ft).
Timing Chain Tensioner Bolt: 20-25 Nm (15-18 lb-ft).
Water Pump Bolts: 20-25 Nm (15-18 lb-ft).
Engine Mount (Main Bracket to Block): 50-55 Nm (37-41 lb-ft).
Engine Mount (Through Bolt): 80-90 Nm (59-66 lb-ft).
The Saab B234R engine was utilized in top-tier Saab
9000 models during its production lifecycle, with limited application in other
platforms.
Saab 9000 Aero: 1993-1997, this was the primary application for the B234R engine
in manual transmission configuration, producing the full 225 PS (165 kW) output.
Automatic transmission variants received the same engine with torque
electronically limited to 294 Nm (217 lb-ft) for transmission durability.
Saab 9000 Carlsson: European market variant of the 9000 Aero, released in
limited numbers during 1996, featuring the B234R engine with identical
specifications to the Aero model.
Saab 9000 Talladega: A limited production run commemorating Saab’s endurance
record at the Talladega Superspeedway, equipped with the B234R engine.
Saab 9-5 Aero (Post-Market): While the factory 9-5 Aero utilized the B235R
engine, the B234R bottom end became a popular substitution in the tuning
community for high-power builds, combining the earlier engine’s robust
construction with the later vehicle platform.
____________________________________________________________________________________
| Car Engines Technical Specifications |
| Small Engines Technical Specifications |
| Industrial Engines Technical Specifications |
| Outboard Engines Technical Specifications |
