ARP Main Stud Kit - Nissan SR20DET | 8740 Chrome Moly | 190,000 PSI (202-5402)

Build your SR20DET bottom end with confidence using the ARP main stud kit. Manufactured from premium 8740 chrome moly steel and heat treated to 190,000 PSI tensile strength, the ARP 202-5402 main stud kit replaces the factory main bearing cap bolts with precision-engineered studs that provide superior clamping force, consistent torque, and improved main bearing cap alignment — essential for any high-performance or high-boost SR20DET build.

Key Features:

• 8740 chrome moly steel construction
• 190,000 PSI tensile strength
• Thread rolled after heat treatment for superior fatigue tolerance
• Precision parallel ground washers included
• Exact tolerances for perfect alignment
• Fits Nissan SR20DET
• ARP quality and engineering

Performance Benefits:

• Superior Clamping Force: 190,000 PSI tensile strength provides greater and more consistent main bearing cap clamping than factory bolts
• Improved Fatigue Tolerance: Thread rolling after heat treatment vastly improves fatigue resistance over conventionally threaded studs
• Consistent Torque: Stud design allows more accurate and consistent torque application than bolts
• Perfect Alignment: Exact tolerances ensure main bearing caps align correctly for optimal bearing clearances
• High-Boost Capable: Engineered for the increased cylinder pressures and block flex of high-boost SR20DET builds
• Parallel Ground Washers: Included washers ensure consistent load distribution under the nuts

Specifications:

• Brand: ARP
• Part Number: 202-5402
• Product: Main Stud Kit
• Material: 8740 chrome moly steel
• Tensile Strength: 190,000 PSI
• Application: Nissan SR20DET
• Includes: Studs, nuts, and parallel ground washers

Fitment Information:

• Nissan Silvia S13 — SR20DET
• Nissan Silvia S14 — SR20DET
• Nissan Silvia S15 — SR20DET
• Nissan 180SX RS13 / RPS13 — SR20DET
• Nissan 240SX S13 / S14 — SR20DET swap
• Note: SR20DET specific — verify fitment for your specific SR20DET variant before ordering
• Installation: Professional installation required — main stud installation is a major engine service requiring engine disassembly

What's Included:

• ARP main studs — complete set for SR20DET (202-5402)
• ARP nuts
• Parallel ground washers
• Note: ARP Ultra-Torque assembly lubricant recommended for installation — sold separately

Installation Notes:

• Professional installation required — engine must be disassembled to access main bearing caps
• Clean all stud holes in the block thoroughly — debris in blind holes causes inaccurate torque readings
• Use ARP Ultra-Torque assembly lubricant on stud threads and under nut faces for accurate torque
• Install studs finger-tight into block — do not use an impact wrench
• Torque nuts to ARP's specified value in the correct sequence
• Verify main bearing clearances after installation

Main Studs vs. Main Bolts — Why Studs Are Superior:

The factory SR20DET uses bolts to secure the main bearing caps to the engine block. While adequate for stock power levels, factory main bolts have limitations that become significant in high-performance builds. When a bolt is torqued, it simultaneously stretches along its length and rotates — the rotational friction during tightening consumes a portion of the applied torque, making it difficult to achieve a precise, consistent clamping force. A stud, by contrast, is installed into the block without rotation and remains stationary during torquing. The nut is then torqued onto the stationary stud, with all of the applied torque going directly into stretching the stud and clamping the bearing cap — resulting in more accurate, consistent clamping force across all main cap positions.

Studs also provide better alignment than bolts. Because the stud is fixed in the block, the main bearing cap slides over the studs and is guided into perfect alignment before the nuts are torqued. This precise alignment is critical for maintaining correct main bearing clearances and ensuring the crankshaft runs true in the block.

8740 Chrome Moly Steel — Material Advantage:

ARP manufactures the 202-5402 from 8740 chrome moly steel — a high-strength alloy steel that provides an excellent combination of tensile strength, fatigue resistance, and toughness. 8740 chrome moly is significantly stronger than the mild steel used in factory fasteners, allowing ARP to achieve 190,000 PSI tensile strength in a fastener that fits the factory stud hole dimensions. This higher strength allows the stud to be torqued to a higher clamping load without yielding, providing greater main bearing cap clamping force than factory bolts can achieve.

Thread Rolling After Heat Treatment — Fatigue Advantage:

ARP's manufacturing process includes a critical step that sets their fasteners apart from conventional aftermarket studs: thread rolling is performed after heat treatment, not before. In conventional fastener manufacturing, threads are cut or rolled before the fastener is heat treated. The heat treatment process can introduce stress concentrations at the thread roots, which are the primary initiation points for fatigue cracks. By rolling the threads after heat treatment, ARP induces compressive residual stresses at the thread roots — the same locations where tensile fatigue stresses are highest during use. These compressive stresses must be overcome before tensile fatigue damage can begin, vastly improving the stud's fatigue life compared to conventionally manufactured fasteners. In a high-boost SR20DET engine where the main studs are subjected to repeated high-amplitude loading from combustion pressure, this fatigue advantage is critical for long-term reliability.

190,000 PSI Tensile Strength — Why It Matters for SR20DET Builds:

The SR20DET's bottom end is subjected to significant stress in high-boost applications. Cylinder pressure from combustion forces the piston down and loads the connecting rod, crankshaft, and main bearings. At high boost levels, these forces are substantially greater than at stock power levels, increasing the load on the main bearing caps and the fasteners that secure them. Factory main bolts are designed for stock power levels and may not provide adequate clamping force at elevated boost, potentially allowing main bearing cap movement that causes bearing wear or failure. ARP's 190,000 PSI tensile strength allows the 202-5402 studs to be torqued to a higher clamping load, ensuring the main bearing caps remain securely clamped even under the extreme cylinder pressures of a high-boost SR20DET build.

ARP Ultra-Torque Lubricant:

ARP specifies their Ultra-Torque assembly lubricant for use with the 202-5402 main stud kit. The torque specifications provided by ARP are developed and validated using Ultra-Torque lubricant — using a different lubricant (engine oil, anti-seize, or dry) will result in a different actual clamping force for the same applied torque value, as friction coefficient varies between lubricants. Using the correct ARP Ultra-Torque lubricant ensures the applied torque accurately translates to the intended clamping force. ARP Ultra-Torque is sold separately and should be ordered at the same time as the stud kit.

Why ARP?

ARP (Automotive Racing Products) is the world's leading manufacturer of high-performance engine fasteners, trusted by professional engine builders and race teams worldwide for their quality, consistency, and engineering excellence. Their fasteners are used in engines competing at the highest levels of motorsport, from drag racing to endurance racing to Formula 1. ARP's commitment to manufacturing quality — including their post-heat-treatment thread rolling process and precision parallel ground washers — ensures every fastener delivers consistent, reliable performance. For SR20DET builds where bottom end integrity is critical, ARP is the only choice.

Perfect For:

• High-boost SR20DET builds requiring upgraded main bearing cap fasteners
• SR20DET engine rebuilds wanting ARP main stud reliability over factory bolts
• Nissan Silvia S13/S14/S15 and 180SX SR20DET performance builds
• 240SX SR20DET swap builds wanting correct ARP main stud kit
• Any SR20DET build where bottom end integrity and main bearing cap clamping are priorities

Perfect For: SR20DET performance builds on Silvia S13/S14/S15, 180SX, and SR20-swapped 240SX requiring ARP main stud kit for superior clamping force, fatigue resistance, and main bearing cap alignment.

Pro Tip: Order ARP Ultra-Torque assembly lubricant at the same time — ARP's torque specifications are developed using Ultra-Torque, and using a different lubricant will result in incorrect actual clamping force for the specified torque value. It's a small cost that ensures the stud kit performs exactly as ARP engineered it to.

8740 Chrome Moly | 190,000 PSI: Thread rolled after heat treat. Parallel ground washers included. SR20DET main bearing caps. Silvia S13/S14/S15, 180SX, 240SX SR20 swap. Professional installation required. Use ARP Ultra-Torque lubricant.

Secure your SR20DET bottom end with ARP 202-5402 main studs — 8740 chrome moly, 190,000 PSI, thread rolled after heat treat, superior clamping force and alignment for high-boost SR20DET builds.