ARP Crankcase Thru Bolt Kit

Multiple Porsche Fitments (204-5405)

Part #: 204-5405

Overview

The ARP Crankcase Thru Bolt Kit is a high-quality upgrade designed for Porsche enthusiasts and professional engine builders seeking enhanced reliability and durability in their engine assemblies. Crafted from premium materials and engineered for precision, this bolt kit ensures your engine's crankcase remains securely fastened under demanding conditions. Whether you're building a performance street engine or a race-ready powerplant, this kit provides the peace of mind that comes with ARP's renowned quality standards.

Specifically tailored for Porsche models with 3.6L and 3.8L engines, this kit addresses the critical need for strong, fatigue-resistant fasteners that can withstand the stresses of high-performance driving. By upgrading your crankcase bolts with ARP's proven design, you'll benefit from improved engine integrity, reduced risk of bolt failure, and enhanced overall engine longevity. This product is ideal for enthusiasts who demand the best in engine hardware and are committed to building reliable, high-performance Porsche engines.

Key Features

ARP's Crankcase Thru Bolt Kit features several advanced design elements that set it apart from standard hardware. Made from forged 8740 chrome moly steel, these bolts are engineered for maximum strength and durability. The bolts are heat-treated and rolled after manufacturing, which significantly enhances their fatigue strength—approximately 2000% better than threaded bolts that are heat-treated prior to threading. This process ensures the fasteners can endure the rigors of high-performance applications without compromising integrity.

• Forged from 8740 chrome moly steel for exceptional strength and toughness.
• Rolled threads after heat treatment provide about 2000% better fatigue strength compared to standard threaded bolts.
• Reduced wrenching head design allows for easier installation and removal in tight engine bays.
• Large underhead radius improves load distribution and minimizes stress concentrations.
• Engineered specifically for Porsche 3.6L and 3.8L engines, ensuring precise fitment and compatibility.
• Designed to withstand the demanding conditions of high-performance and racing environments.
• Manufactured to meet or exceed OEM standards for quality and reliability.

Construction & Design

The ARP Crankcase Thru Bolt Kit is meticulously crafted from high-grade 8740 chrome moly steel, a material renowned for its excellent strength-to-weight ratio and resistance to fatigue. The bolts feature a rolled thread process after heat treatment, which enhances their fatigue life and overall durability. The reduced wrenching head design simplifies installation in confined engine spaces, making maintenance and assembly more straightforward. The large underhead radius ensures even load distribution, reducing stress concentrations that could lead to bolt failure over time.

Designed with precision engineering, these bolts provide a secure fit that maintains engine integrity during high-stress conditions. The high-quality manufacturing process ensures consistent thread engagement and reliable clamping force, critical for maintaining proper engine sealing and performance. Whether used in rebuilds, performance upgrades, or race applications, these bolts are built to last and perform under extreme conditions.

Installation & Fitment

The ARP Crankcase Thru Bolt Kit is designed as a direct bolt-on replacement for factory fasteners on compatible Porsche 3.6L and 3.8L engines. Installation is straightforward for experienced mechanics or enthusiasts familiar with engine assembly. No special tools beyond standard hand tools are required, and no cutting or drilling is necessary. Proper torque specifications should be followed to ensure optimal clamping force and engine integrity. Always refer to the vehicle's service manual for specific torque values and installation procedures.

• Easy, bolt-on installation with standard hand tools.
• No cutting, drilling, or modifications required.
• Ensure proper torque to maximize fastener performance and engine reliability.

What's Included

• Complete set of ARP Crankcase Thru Bolts for Porsche 3.6L & 3.8L engines
• Necessary hardware and washers (if applicable)
• Installation instructions and technical data sheet

Ideal For

This bolt kit is perfect for Porsche owners and professional rebuilders aiming to enhance engine durability and reliability. It is especially recommended for high-performance builds, racing applications, or any scenario where engine integrity under stress is critical. If you are upgrading your engine or performing a rebuild, ARP's fasteners provide the confidence that your engine will withstand demanding conditions.