Top 10 Engines That Deserve Forged Crankshafts

Every performance build starts with a strong foundation. When it comes to engine reliability under extreme power, few components are as critical as the crankshaft. Acting as the backbone of the bottom end, the crankshaft converts linear piston motion into rotational force. However, stock cast crankshafts, even when well-engineered, simply aren’t designed for the sustained punishment of high horsepower builds. This is where forged crankshafts step in. With superior strength, fatigue resistance, and customization options, they become the foundation for reliable high-performance engines.

What Makes Forged Crankshafts Essential?

Before we break down the engines, let’s establish why forged crankshafts are so critical.

📊 Stock vs Forged Crankshaft – Key Differences

Top 10 Engines That Deserve Forged Crankshafts

The Toyota 2JZ-GTE has earned its reputation as one of the strongest production engines ever built. Stock cranks are impressive, but once you push beyond 800–1000 horsepower, fatigue becomes a concern.

• Why it needs a forged crankshaft: Big boost drag builds often run massive turbos, subjecting the crank to extreme torsional stress.
• Tuning potential: With a forged crank, 2JZ engines can reliably exceed 1200+ hp.
• KingTec solution: Custom-stroke 2JZ forged crankshafts available for stroker kits, enhancing torque while retaining balance at high RPM.

The Skyline GT-R’s RB26 is an icon in both motorsport and street tuning. Known for revving to the moon, it also suffers from crankshaft stability issues at extreme RPM.

• Why it needs a forged crankshaft: Factory units can flex, leading to main bearing wear.
• Tuning potential: With a forged crank, the RB26 can hold together in 1000 hp builds while staying smooth at 9000+ RPM.
• KingTec solution: Lightweight RB26 forged cranks reduce rotational mass while increasing strength, ideal for drift and time attack builds.

The Honda K24 has become a swap legend. Affordable, versatile, and capable of handling big power with the right internals, it’s a favorite for turbo builds.

• Why it needs a forged crankshaft: High boost and aggressive revving create fatigue cycles that can crack stock cranks.
• Tuning potential: Forged cranks allow K24 builds to safely exceed 700+ hp.
• KingTec solution: Precision-balanced K24 forged crankshafts for K-series swaps, perfect for both street and track applications.

The BMW N55 single-turbo inline-six carried the torch after the N54, offering strong performance and wide tuning potential. However, when power levels climb well past factory specs, the crankshaft becomes a critical weak point.

• Why it needs a forged crankshaft: The stock crank struggles under high boost and torque loads, especially in sustained track or drag use.
• Tuning potential: With a forged crank, the N55 can safely support 750–850 hp, unlocking its full potential.
• KingTec solution: KingTec N55 forged crankshafts feature precision balancing and enhanced oiling for maximum reliability at high RPM and high boost.

The Mitsubishi 4G63 powered generations of Evos and is famous in rally and drag racing. However, crankwalk and fatigue failures are well-documented.

• Why it needs a forged crankshaft: Hard launches and aggressive revving in rally stages stress the crank.
• Tuning potential: Forged crankshafts allow consistent reliability at 600–900 hp builds.
• KingTec solution: Shot-peened and nitrided 4G63 forged crankshafts for maximum fatigue life, perfect for endurance racing.

The Subaru EJ20 is a legend in motorsport history, powering everything from early WRX models to championship-winning rally cars. Compact, rev-happy, and boost-friendly, it remains a favorite among Subaru tuners worldwide.

• Why it needs a forged crankshaft: Stock EJ20 cranks can suffer from journal wear and flex when subjected to high boost and prolonged high RPM, especially in racing conditions.
• Tuning potential: With a forged crankshaft, the EJ20 can safely support 500–700 hp, unlocking its true potential for both street and track builds.
• KingTec solution: KingTec forged EJ20 crankshafts are manufactured from premium 4340 billet steel, heat-treated and nitride-hardened for maximum durability. Each unit is dynamically balanced to ensure stability at extreme RPM and boost levels, making it the perfect upgrade for serious Subaru builds.

The Land Rover 448DT V8 diesel is built for torque, but once modified for tuning or heavy-duty use, the crankshaft is heavily stressed.

• Why it needs a forged crankshaft: High torque at low RPM places immense stress on the journals.
• Tuning potential: Forged cranks ensure durability for off-road, towing, and performance diesel applications.
• KingTec solution: Heavy-duty 448DT forged crankshafts with improved oiling and fatigue resistance.

The VW EA113 2.0 TFSI is a turbocharged platform popular in both daily performance cars and serious track builds.

• Why it needs a forged crankshaft: High boost pressures and aggressive tuning push the limits of the stock unit.
• Tuning potential: Forged crankshafts unlock safe 500–700 hp builds.
• KingTec solution: Precision-forged crankshafts for EA113, compatible with forged pistons and rods for a complete bottom-end upgrade.

The BMW S63 twin-turbo V8 found in M5s and M6s is a beast right out of the factory, but it’s also a favorite for high-power tuning.

• Why it needs a forged crankshaft: Twin-turbo torque delivery stresses the crankshaft under both street and track use.
• Tuning potential: Forged crankshafts stabilize high-boost builds exceeding 1000 hp.
• KingTec solution: Forged and nitrided S63 forged crankshaft with exacting tolerances to withstand extreme torque loads.

The Toyota 4A-GE is an older but beloved platform, especially in AE86 builds and grassroots motorsports. While not known for huge horsepower, it benefits greatly from durability upgrades.

• Why it needs a forged crankshaft: High-RPM use in track builds and forced induction conversions push stock cranks to their limit.
• Tuning potential: Forged cranks ensure reliability in 300–400 hp boosted applications while maintaining rev-happy character.
• KingTec solution: Lightweight 4AGE forged crankshaft engineered for classic 4A-GE builds, keeping the spirit of the platform alive.

📊 Popular Engines & Recommended Power with Forged Crankshafts

Beyond the Crankshaft: Complete Engine Balance

A forged crankshaft on its own is a massive upgrade, but for ultimate reliability, it should be paired with forged pistons and connecting rods. The synergy of these components ensures balance, prevents destructive harmonics, and enables the engine to fully harness the benefits of forced induction or high RPM tuning.

For those chasing displacement, stroker kits (forged crank + rods + pistons) unlock even greater performance by increasing stroke length. KingTec Racing specializes in such solutions, tailoring kits for specific applications.

Buying Guide: Choosing the Right Forged Crankshaft

When selecting a forged crankshaft, consider the following:

Whether you’re pushing a Toyota 2JZ to 1500hp, revving an RB26 to 9,000 RPM, or relying on the brute torque of a diesel 448DT, one fact is clear: the crankshaft is the foundation of engine performance.
At KingTec Racing, we specialize in precision-forged crankshafts for all these engines and more. With advanced forging processes, nitriding, CNC finishing, and strict balancing, our crankshafts are engineered to handle the toughest conditions. We also provide custom stroke options for stroker kits, ensuring your build is tailored for maximum performance.

Your build deserves a crankshaft as strong as your ambitions. Contact KingTec Racing today and let’s power your project to the next level!