SCAT 4-LS1-4000-6125-58 Standard Steel Crankshaft 099998154888 4LS140065 4340

( Brand: Scat ), ( Manufacturer Part Number: 4-LS1-4000-6125-58 ), ( Part Type: Crankshaft ), ( UPC: 099998154888 )

Review SCAT Standard Weight 4340 Steel Crankshaft

The **SCAT 4LS1-4000-6125-58 Standard 4340 Steel Crankshaft** is a meticulously engineered, high-performance component designed to deliver uncompromising strength, durability, and reliability for high-output small-block Chevrolet applications, particularly those built around the legendary **LS1 architecture**. Crafted from **AISI 4340 alloy steel**, this crankshaft is forged to exacting standards, ensuring exceptional fatigue resistance, torsional stiffness, and resistance to warping or distortion under extreme stress qualities essential for aggressive engine builds, forced induction setups, or heavy-duty street and racing applications. The **4LS1-4000** designation indicates a **4-bolt main journal** configuration, a hallmark of the LS1 platform, which enhances rigidity and reduces oil leakage while maintaining compatibility with stock and aftermarket LS1/Gen III/Gen IV engine blocks. With a **main journal diameter of 2.500 inches** and **rod journal diameters of 2.000 inches**, this crankshaft strikes an ideal balance between strength and weight, allowing for optimal power delivery without excessive reciprocating mass. The **6125 main bearing surface finish** ensures smooth operation and minimizes friction, while the **58 rod bearing surface finish** further optimizes lubrication and longevity, particularly under high RPM or heavy loads. The crankshaft features **counterweighted mains and rods**, meticulously balanced to minimize vibration and enhance drivability, making it suitable for both street-driven daily drivers and high-revving performance engines. Whether paired with a **supercharged, turbocharged, or naturally aspirated LS1-based engine**, this crankshaft is engineered to withstand the demands of modern high-performance applications, from **nitrous oxide setups** to **high-compression forced induction builds**. Built to SCAT s rigorous standards, this crankshaft is not only a direct replacement for OEM components but also an upgrade in strength and precision, ensuring that your engine operates with the reliability and power it deserves.

### **Pros and Cons of buying a SCAT 4-LS1-4000-6125-58 (4LS140065) Standard 4340 Steel Crankshaft**

1. **High-Quality Material (4340 Steel)** This crankshaft is forged from 4340 steel, a premium alloy known for its strength, durability, and resistance to fatigue. It can handle high RPMs and heavy loads better than cast iron or lower-grade steel.

2. **Balanced and Precision-Machined** SCAT cranks are designed with precision balancing and machining, ensuring smooth operation and reduced vibration. This is particularly important for high-performance applications where stability is critical.

3. **Compatibility with LS1 Engines** This specific crankshaft is engineered for the **LS1 engine family** (e.g., 4.3L, 5.3L, 6.0L applications), meaning it will fit stock LS1 blocks without major modifications. It s also compatible with aftermarket blocks designed for LS1 architecture.

4. **Standard Configuration for Reliability** The "standard" designation suggests it is a well-tested, production-style crank rather than a custom or experimental design. This reduces the risk of unforeseen issues that might come with non-standard parts.

5. **Warranty and Support** SCAT is a reputable manufacturer with a strong reputation for customer support and warranties. This provides peace of mind in case of defects or installation issues.

6. **Potential for Forged Rods and Pistons** Since this is a forged crank, it pairs well with other forged components (e.g., rods, pistons), allowing for a fully forged engine build if desired.

7. **Aftermarket and Performance Potential** While this is a stock-style crank, it can still be used in **forced induction (turbo/supercharged) applications** if paired with appropriate supporting components (e.g., upgraded rods, bearings, and oil system).

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1. **Cost Compared to Stock** A forged 4340 steel crankshaft will be significantly more expensive than an OEM cast iron crank. The price reflects its superior material and machining quality, but it may not be cost-effective for mild street applications where stock performance is sufficient.

- **Upgraded connecting rods** (if not already using forged rods).

- **High-quality bearings** (e.g., ISC, Clevite, or aftermarket options).

- **A robust oil system** (e.g., catch cans, upgraded oil pump, or external oil cooler for forced induction).

- **Proper lubrication** (high-performance oil with the right viscosity).

Without these, the crank may not see significant benefits, and stress could be unevenly distributed.

3. **Installation Complexity** Replacing a crankshaft requires **specialized tools, experience, and precision**. If not installed correctly, it can lead to **rod bearing failure, oil leaks, or even catastrophic engine damage**. This is not a DIY job for most enthusiasts.

4. **Limited Power Gains Over Stock (Without Modifications)** If you re running a **stock LS1 engine with no forced induction or significant tuning**, the power gains from a forged crank may be minimal. The real benefits come in **high-RPM, high-torque, or forced induction applications**.

5. **Weight Consideration** While 4340 steel is strong, it is also **heavier than cast iron**. This can slightly reduce revving potential unless the engine is tuned accordingly.

6. **Potential for Overkill** If your primary goal is **daily driving or mild performance**, a stock crank may suffice. A forged crank is more suited for **track use, heavy hauling, or forced induction builds**.

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The **SCAT 4-LS1-4000-6125-58 (4LS140065) 4340 steel crankshaft** is an excellent choice for **high-performance, durability-focused, or forced induction LS1 builds**. Its superior material and machining make it ideal for applications where **reliability under stress, high RPMs, or forced induction** are priorities. However, it is **not a necessary upgrade for stock or mildly modified engines** and comes with a **higher cost and installation complexity**.

- You are building a **forced induction (turbo/supercharged) LS1 engine**.

- You are running **high RPMs consistently** (e.g., track use, heavy-duty applications).

- You are pairing it with **other forged components (rods, pistons)** for a fully upgraded engine.

- You have **professional installation** (or extensive experience) to ensure proper setup.

- You are running a **stock or mildly modified LS1 engine** without forced induction.

- Your budget is limited, and you prioritize **cost-effectiveness over extreme durability**.

- You lack the **tools, experience, or support** for a proper crankshaft replacement.

For most **street-driven LS1 engines**, a **stock crank or a high-quality aftermarket cast iron crank** (e.g., JE, Scat s cast iron options) may be sufficient. The **4340 forged crank is best reserved for serious performance builds where reliability under extreme conditions is critical.**

Details:

American Express. Scat Standard Weight 4340 Steel Crankshaft Chevy LS1 Super Stock Series, Crankshaft, 4.000 Stroke for use with 6.125 Rod, 2.100 Rod Pin Diameter, 58-Tooth Rector Wheel, 6-Bolt Flange, 50 lbs.

part #: 4ls14000612558 price

• $1119.04

specifications cranshafengin:

• brand: Scat
• mpn: 4-ls1-4000-6125-58
• part type: Crankshaft
• upc: 099998154888

general cranshafengin:

• Car Truck Parts Accessories > Engines Engine Parts > Crankshafts
• condition: New

shipping cranshafengin:

• type: Fixed
• cost: $0.00
• service: Standard
• transit: 4-8 Days
• class: Standard

seller cranshafengin:

• # reviews: 622494
• rating: 99.3%
• city: , Ohio

payments cranshafengin:

• wallet: Paypal
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• credit card: Visa

offer cranshafengin:

• sold: 0
• started: March 27, 2026
• quantity: 10
• availability: In Stock
• options: Ship-to-home

returns cranshafengin:

• paid by: Seller
• time: 30 Days
• policy: Returns Accepted

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