Toyota 2JZ vs BMW B58: A Detailed Engine Internal Comparison
The Toyota 2JZ and BMW B58 represent two of the most respected modern inline-6 engines. The iron-block 2JZ debuted in 1991 powering icons like the fourth-generation Supra. The B58 arrived in 2015 as BMW’s latest 3.0L technological tour-de-force, delivering leading power, efficiency, and emissions performance.
While the B58 surely demonstrates advanced innovation, the 2JZ retains immense appeal among purists and tuners for its simplicity paired with exceptional reliability when modified. This guide will compare critical design elements including the crankshafts, cylinder heads, oiling systems, and valvetrain technology. We’ll highlight factors enabling the 2JZ’s extreme performance potential versus the B58’s modern sophistication.
Crankshaft and Block Design
The BMW B58 crank leverages hollow-drilled high-strength steel paired with an intricate 8-counterweight system designed to nearly eliminate vibrations. Connecting rod journal diameters measure 54mm, with a 90.0mm stroke in a closed-deck block. Unfortunately, early B58s suffered timing chain guide failures due to inadequate oiling distribution to the crank nose area. BMW remedied this issue in 2018+ production engines by enhancing lubrication pathways.
In contrast, the iconic 2JZ uses a stout cast iron engine block designed for rugged durability. An 87.0mm stroke combines with an oversquare 86mm bore (even larger on 2JZGE models) for 3.0L of displacement. Its forged steel crankshaft and main bearing caps secure four conventional counterweights. This straightforward design prioritizes strength for high-RPM stability despite increased vibration. Durability enables tuners to exceed 800+ wheel horsepower with sufficient supporting modifications.
Engine architecture also plays a role. The 2JZ mounts its turbocharger low in the valley area for compact packaging amid excellent access for modifications or repairs. The B58 integrates its twin-scroll turbo completely within the cylinder head, improving emissions but compromising accessibility.
Table 1 below summarizes key crankshaft specification differences:
| Specification | Toyota 2JZ | BMW B58 |
|---|---|---|
| Deck Design | Closed | Closed |
| Stroke (mm) | 87.0 | 90.0 |
| Conrod Length (mm) | 155 | 150 |
| Journal Diameter (mm) | 57 | 54 |
| Crank Material | Forged Steel | Hollow-Drilled Steel |
| Counterweights | 4 | 8 |
The B58 also incorporates Nikasil coated cylinder walls, enabling thinner and lighter walls together with lower rotating mass compared to the 2JZ. This allows higher RPM capabilities despite increased friction. Lightweight forged aluminum pistons and fractured cap connecting rods designed for high-rpm operation match the B58’s free-revving character. The 2JZ uses thick cast hyper-eutectic pistons for extreme thermal survival even at over 30psi boost. It also offers forged variants in certain trim levels and years providing a weight savings advantage.
In summary, both engines adopt impressive technology given their target applications, but the 2JZ’s simpler architecture centered on basis durability continues enabling extreme modified horsepower.
Cylinder Head and Valvetrain Design
The B58 twin-scroll turbocharged engine realizes remarkable specific output thanks partly to BMW’s advanced Valvetronic variable valve lift technology. This functions alongside Double VANOS variable camshaft timing to enable continuously optimized valve operation based on factors like engine speed, load, and temperature. The intricacy of this valvetrain facilitates the B58’s free-revving torque delivery and 8600 RPM redline for an elite driving experience. However, it generally sacrifices ultimate peak horsepower compared to more aggressive camshaft profiles.
In contrast, the Toyota 2JZ uses six individual tuned intake runners versus the B58’s siamesed inlet design. This facilitates better cylinder-to-cylinder air distribution at extreme power levels. All 2JZ cast iron cylinder heads innately resist detonation and enable reliable sealing thanks to the multi-layer steel head gasket up to 0.7mm thickness. The non-VVT 2JZ retains a cult following with its 236/240-duration cams tolerant of high boost pressures. Later 2JZrevisions added variable cam timing technology as well, but the engine’s performance ceiling remains sky-high regardless.
The B58 head must integrate spark plugs and high-pressure direct injection hardware necessitating valve shrouding. This reduces total valve curtain area relative to the 2JZ, especially on the intake side. There are also risks associated with localized hotspots from injector spray that must be mitigated to avoid detonation damage when tuning.
Enthusiasts continue gravitating to the 2JZ head for its uncomplicated fixed-lift design that responds well to upgrades. Meanwhile, the B58 engine trades top-end horsepower in stock form for a broader powerband, efficiency gains and stringent emissions compliance.
Oiling System and Cooling Factors
The Toyota 2JZ utilizes a gear-driven pump adequately sized to maintain oil pressure even at high RPM. A shallow cast-in sump integrates a windage tray to limit parasitic losses while the front-mounted oil filter simplifies access. These enhancements support the 2JZ’s mechanical integrity when boosted over 600 horsepower but remain outperformed by modern designs regarding oil control under intense cornering loads. Most hardcore 2JZ builds upgrade to either twin-screw or dry sump arrangements when exceeding 800+ horsepower.
In stark contrast, the B58 adopts a two-stage variable displacement oil pump precisely matching pressure to engine demands including factors like rotating speed and oil temperature. The pump incorporates valve actuation controlling discharge volume together with two pressure relief valves stabilizing pressure spikes. This highly engineered system reduces parasitic losses especially during cold operation but introduces complexity that may eventually compromise durability past ~650hp without upgrading.
Regarding cooling efficacy, both engines rely on efficient cross-flow circulation throughout the block and head to resist excessive heat. The fourth-generation Toyota Supra’s 2JZ-GTE benefited from dual oil coolers plus a large side-mount air-to-air intercooler effectively shielding the engine bay from heat soak effects even at 500+ wheel horsepower. BMW designed the B58 for 650hp in OEM trim within the Supra engine bay thanks partly to a 6-layer MLS head gasket, secondary radiators plus an air-to-water charge cooler integrated within the intake manifold.
In summary, both engines deliver impressive thermal endurance despite forced induction, with the 2JZ boasting years of evidence from extreme turbo builds and the B58 applying sophisticated modern cooling and lubrication strategies.
Aftermarket Support and Tuning Potential
Arguably the predominant reason the Toyota 2JZ endures as an icon is its immense aftermarket support catering specifically to turbocharged performance. Companies like Brian Crower, Eagle, Manley, ACL, and Cometic have engineered upgraded components enhancing airflow, durability, and power handling explicitly for 2JZ platforms ranging from the Supra to Lexus IS300. The scale of this enthusiast focus simply does not exist yet for the still-new B58 engine.
The 2JZ’s overbuilt internal design takes well to upgrading internals like engine rods, pistons, and multi-layer steel head gaskets to manage boost levels exceeding 60+ PSI pressure without failure. This facilitates turbo kits from names like Garrett, Precision, Borg Warner, and GReddy to unlock four-figure horsepower figures as evidenced in Table 2 below:
| 2JZ Engine | Turbocharger | Fuel Type | Peak WHP |
|---|---|---|---|
| 2JZGTE | Garrett GTX5533R Gen II | E85 | 1,007 |
| 2JZGTE | Borg Warner S475 | E85 | 1,253 |
| 2JZGE | Precision 8385 | E85 | 1,376 |
These staggering power figures demand serious engine build requirements including forged internals, multi-layer steel head gaskets, high-flow exhaust manifolds, and either twin-fuel pump or direct port methanol injection. However, the essential 2JZ bottom end regularly withstands this abuse without failure when adequately maintained.
The BMW B58 elevated expectations for a stock turbocharged engine but still lacks substantive evidence supporting quad-digit power claims long-term. BMW performance partner Alpina coaxes 621 horsepower from the B58 using special Mahle pistons, modified rods, and a bespoke cylinder head paired with twin-scroll Borg Warner turbos. Companies like Pure Turbos, Vargas Turbochargers and FP Tuning offer bolt-on upgrades lifting output potential for otherwise stock B58 Supras. But 1000+ horsepower B58 builds currently remain unicorns, with just 750 horsepower presenting challenges with engine cooling, oiling and timing chain tension.
If targeting maximum affordable power potential, the 2JZ remains a top choice thanks to immense real-world testing up to 1300+ horsepower. The B58 promises similar potential with sophisticated factory engineering, but truly extreme builds demand levels of customization not yet possible given the aftermarket parts availability.
Summary – Characteristics Defining These Iconic Engines
BMW’s turbocharged B58 clearly leverages superior technology like closed-loop fuel injection, Valvetronic variable valve lift, and multi-stage variable oil pumps. This unlocks incredible 339hp per liter specific output paired with potent mid-range torque and silky high-RPM power delivery. Engineers optimized the B58 masterfully within packaging, performance and emissions constraints.
However, the Toyota 2JZ created an automotive icon via its overbuilt durability and immense tuning potential. The stout iron long block, six-port head design, thick MLS gasket and forged crankshaft cement its status for supporting extreme horsepower builds. While the B58 promises increased complexity and technology, modified Supra 2JZs still make 1300+ horsepower reliably.
Much comes down to character. The BMW B58 represents amazing technological achievement applied to a road car engine. But the Toyota 2JZ made its name standing timeless as testament to the sheer desirability of an overbuilt inline-six optimized for big-power builds. Given that masterful brew of engineering margin, simplicity and bulletproof reliability, it’s no surprise enthusiasts continue cherishing the legendary 2JZ over 20 years on.