1. Engine Crankshafts Products
  2. sku: 20596370656348632
  3. MOLNAR 400-3800CB6F-585

MOLNAR TECHNOLOGIES 400-3800CB6F-585 Forged Crank Mains 3.800

fits model: 800, 400.

400-3800cb6f-585 Molnar Technologies Sbc Forged Crank 3.800 Stroke 400 Mains

( Brand: Molnar Technologies ), ( Manufacturer Part Number: 400-3800CB6F-585 ), ( Part Type: Crank ), ( Performance Part: Yes )

Review MOLNAR TECHNOLOGIES Sbc Forged Crank 3.800 Stroke Mains fits 800 400

The **Molnar 400-3800CB6F-58 Forged Crankshaft (3.800" Main Journal, 400" Rod Journal)** is a premium, high-performance component meticulously engineered for applications demanding exceptional strength, durability, and precision. Crafted from **high-quality forged steel**, this crankshaft is designed to withstand the rigorous demands of heavy-duty engines, whether in industrial machinery, marine propulsion systems, or high-output automotive and truck applications. The **3.800-inch main journal** provides robust support for the engine s load-bearing requirements, ensuring minimal deflection and optimal power transfer, while the **400-inch rod journal** delivers the necessary articulation for smooth piston movement, reducing stress on connecting rods and bearings. Molnar s proprietary forging process eliminates internal voids and inconsistencies, resulting in a homogeneous, stress-relieved structure that enhances fatigue resistance and extends the crankshaft s operational lifespan. The **balanced and dynamically corrected** design minimizes vibration, contributing to smoother engine operation and reduced wear on associated components. Ideal for engines requiring a balance of power and reliability, this crankshaft is a testament to Molnar s commitment to precision engineering, offering a robust solution for builders and mechanics seeking a dependable, high-performance component for their high-stress applications.

**Pros and Cons of buying a Molnar 400-3800CB6F-585 Forged Crank (3.800" 400 Main Journals)**

### **Pros**

1. **High-Quality Forged Construction** Molnar cranks are known for their precision-forged steel, which offers superior strength, durability, and resistance to fatigue compared to cast or billet cranks. This makes them ideal for high-performance applications, including forced induction and heavy-duty use.

2. **Balanced and Smooth Operation** The crank is designed with careful attention to balance, reducing vibration and improving overall engine smoothness. This is particularly beneficial for high-RPM applications, such as turbocharged or supercharged engines.

3. **Precision Machining** Molnar cranks undergo rigorous machining processes to ensure tight tolerances, which enhances reliability and longevity. This precision also helps maintain optimal engine performance.

4. **Compatibility with High-Performance Engines** The 3.800" main journal size is a premium dimension, often used in high-output engines where additional strength is required. This crank is suitable for engines with significant power demands, such as those with forced induction or aggressive tuning.

5. **Warranty and Support** Molnar is a reputable manufacturer with a strong reputation for customer support and warranties, which can provide peace of mind when investing in a high-end component.

6. **Customization Options** Molnar offers various crank configurations, including different rod journal sizes and balancing options, allowing for tailored solutions to fit specific engine builds.

7. **Durability for Extreme Conditions** The forged steel construction is well-suited for extreme environments, such as drag racing, high-altitude driving, or heavy-duty towing, where reliability is critical.

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### **Cons**

1. **High Cost** Forged cranks from Molnar are significantly more expensive than standard cast or billet cranks. The premium price reflects the quality and precision, but it may not be justified for stock or mildly modified engines.

2. **Limited Availability and Lead Times** High-demand cranks like this may have longer lead times due to production schedules. This could delay engine assembly if you're on a tight timeline.

3. **Requires Professional Installation** While Molnar cranks are robust, they often require specialized tools and expertise for proper installation, such as balancing and alignment. Improper installation can compromise performance and longevity.

4. **Overkill for Stock or Mildly Modified Engines** If your engine is not heavily modified or not subjected to extreme stress, a forged crank may offer little practical benefit over a high-quality cast or billet crank. The additional cost may not be justified for stock or lightly tuned applications.

5. **Weight Considerations** Forged cranks are heavier than some billet or cast alternatives. While this can improve inertia and balance, it may not be desirable in applications where weight reduction is critical (e.g., racing where every gram counts).

6. **Potential for Over-Tuning** Some builders may be tempted to push the engine beyond its intended limits with a forged crank, leading to premature wear of other components (e.g., rods, bearings) if the rest of the engine is not adequately supported.

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### **Conclusion and Recommendation**

The **Molnar 400-3800CB6F-585 forged crank (3.800" mains)** is an excellent choice for **high-performance, heavily modified, or forced-induction engines** where durability, precision, and reliability are paramount. Its forged construction, balanced design, and compatibility with aggressive power levels make it a top-tier option for builders targeting extreme performance or longevity under heavy stress.

However, for **stock, mildly modified, or budget-conscious builds**, the cost may not be justified. In such cases, a high-quality cast or billet crank from a reputable manufacturer (e.g., JE, Scat, or Crane) could offer a more cost-effective solution without sacrificing performance.

**Final Recommendation:**

- **Buy it if:** You are building a **high-performance, forced-induction, or drag-racing engine** where strength, balance, and reliability are critical. The investment in a Molnar crank will pay off in terms of durability and performance.

- **Avoid it if:** Your engine is **stock, mildly modified, or not subjected to extreme stress**. In these cases, a more affordable crank will suffice without the premium cost.

- **Consider alternatives if:** You need **weight savings** or a **shorter lead time**, as other manufacturers may offer comparable performance at a lower price.

For most **serious builders pushing significant power**, the Molnar crank is a **strong recommendation** due to its proven track record and engineering excellence. For everyone else, weigh the cost against your engine s actual needs before committing.

Details:

Manufacturer: Molnar Technologies. Crankshaft - 3.800 in Stroke Internal Balance Forged Steel 2-Piece Seal 400 Mains Small Block Chevy Each.

part #: 4003800cb6f585 prices

  • $1114.88-$1169.60

specifications cranshafengin:

  • for models: 800, 400
  • brand: Molnar Technologies
  • mpn: 400-3800cb6f-585
  • part type: Crank
  • performance part: Yes

payments cranshafengin:

  • credit card: Discover
  • wallet: Google-pay
  • other

offer cranshafengin:

  • quantity: 2
  • started: May 28, 2026
  • availability: In Stock
  • options: Ship-to-home
  • sold: 0

shipping cranshafengin:

  • transit: 4-7 Days
  • cost: $0.00
  • service: Standard
  • type: Fixed
  • class: Standard

seller cranshafengin:

  • # reviews: 132319
  • rating: 99.9%
  • city: San Leandro, California

general cranshafengin:

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

returns cranshafengin:

  • policy: Returns Accepted
  • time: 30 Days
  • paid by: Seller
for models: 800, 400, part type: crank, performance part: yes,
category: auto parts > car truck parts accessories > engines engine parts > crankshafts, sku: 20596370656348632,
Molnar Technologies 400-3800CB6F-585 Is Similar To:
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2 offers $1114.88–$1169.60 USD
  • New. Offer #1 priced at $1114.88 + $0.00 shipping estimate = $1114.88* total. Crankshaft - 3.800 in Stroke - Internal Balance - Forged Steel - 2-Piece Seal - 400 Mains - Small Block Chevy - Each. Manufacturer: Molnar Technologies.FREE SHIPPING
  • New. Offer #2 priced at $1169.60 + $0.00 shipping estimate = $1169.60* total. If a defect is identified after this period, it will fall under the manufacturer's warranty and should be handled directly with them.FREE SHIPPING

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