Nissan QG15DE / QG16DE / QG18DE ARP Cylinder Head Stud Kit

Upgrade the cylinder head fastening on your Nissan QG engine with an ARP high-strength head stud conversion.

Suitable for QG15DE, QG16DE and QG18DE engines, this kit provides a strong and reusable alternative to the factory-style cylinder head fasteners, making it particularly suited to performance engine builds, turbocharged applications and engines that may be regularly stripped and rebuilt.

Key Features

• Suitable for Nissan QG15DE, QG16DE & QG18DE Engines
• Genuine ARP Fasteners
• Manufactured from High-Strength ARP 8740 Chrome Moly
• Reusable when Correctly Installed & Remaining Serviceable
• Precision Centreless-Ground Studs
• Threads Rolled After Heat Treatment
• Hardened Parallel Washers
• High-Strength Nuts Included
• Ideal for Naturally Aspirated & Forced-Induction Builds
• Excellent Upgrade During an Engine Rebuild

Why Upgrade to Head Studs?

The cylinder head is subjected to considerable forces during combustion, particularly as cylinder pressure increases.

Maintaining consistent clamping between the cylinder head, head gasket and engine block therefore becomes increasingly important as engine performance is increased.

This makes an upgraded head fastening arrangement particularly worthwhile for:

• Turbocharged QG Engines
• Supercharged Applications
• Higher Boost Levels
• Higher Compression Builds
• Performance Camshafts
• Modified Cylinder Heads
• Increased RPM
• Track & Competition Engines

ARP head studs provide a high-strength fastening solution designed to provide accurate and repeatable cylinder head clamping when correctly installed.

ARP 8740 Chrome Moly

ARP's 8740 chrome moly is a high-strength fastener material widely used throughout performance and motorsport engine applications.

The material can be heat-treated to provide extremely high tensile strength while maintaining the fatigue properties required for demanding engine applications.

ARP also centreless-grinds its studs to ensure concentricity and straightness, with the threads rolled after heat treatment to improve fatigue strength.

Reusable Fasteners

One of the major advantages of converting to ARP studs is serviceability.

Unlike single-use torque-to-yield fasteners, ARP studs can be reused provided they remain within specification and have been correctly:

• Installed
• Torqued
• Maintained
• Removed
• Cleaned
• Inspected Before Reassembly

This can be particularly useful on development, race and high-performance engines where the cylinder head may be removed more regularly.

Any fastener showing evidence of thread damage, corrosion, galling, permanent deformation or other deterioration should be replaced.

More Consistent Cylinder Head Clamping

A stud arrangement separates installation of the fastener into the block from the final clamping of the cylinder head.

The cylinder head is positioned over the installed studs before the nuts and hardened washers are tightened.

When installed using the correct lubricant and procedure, this provides an accurate and repeatable method of applying cylinder head clamping force.

Ideal for Turbocharged QG Engines

The QG15DE, QG16DE and QG18DE have become popular choices for modified and engine-converted vehicles, including turbocharged applications.

As boost pressure and cylinder pressure increase, maintaining the seal between the cylinder head and engine block becomes increasingly important.

For this reason, an ARP stud conversion is a sensible consideration when building a:

• Turbocharged QG15DE
• Turbocharged QG16DE
• Turbocharged QG18DE
• Supercharged QG Engine
• High-Compression Naturally Aspirated QG
• Track or Competition QG Engine

Head studs themselves do not increase horsepower.

Their purpose is to provide a stronger and more consistent method of maintaining cylinder head clamping as part of a properly built engine.

Compatibility

Suitable for:

Nissan QG15DE
Nissan QG16DE
Nissan QG18DE

ARP Kit Reference

ARP Part Number: 202-4304

⚠️ IMPORTANT ARP APPLICATION NOTE

ARP does not officially catalogue part number 202-4304 as a Nissan QG15DE, QG16DE or QG18DE application.

The original ARP catalogue application for 202-4304 is the Nissan KA24DE 2.4L DOHC engine.

This kit is offered for the QG engine based on its suitability as a cross-application component rather than being an officially catalogued QG application from ARP.

Customers should therefore not automatically use published KA24DE installation or torque specifications on a QG engine.

The correct installation and tightening procedure for the QG application should be established by the engine builder.

What's Included?

• Complete ARP Cylinder Head Stud Set
• Matching High-Strength Nuts
• Hardened Parallel Washers

⚠️ PROFESSIONAL INSTALLATION REQUIRED

Cylinder head fasteners are critical engine components and should be installed by a suitably qualified engine builder or technician.

Before assembly:

• Clean & Inspect the Block Threads
• Check Stud Thread Engagement
• Inspect the Cylinder Head
• Check Block & Head Mating Surfaces
• Confirm Correct Head Gasket
• Check Stud Length & Clearance
• Install Studs Correctly
• Use the Appropriate Fastener Lubricant
• Follow the Correct Tightening Sequence
• Follow an Appropriate QG Torque/Preload Procedure

DO NOT SIMPLY USE THE FACTORY HEAD-BOLT TORQUE SPECIFICATION

ARP studs should not automatically be tightened using the original Nissan torque-to-yield head bolt procedure.

Likewise, because 202-4304 was originally developed for the KA24DE, the published ARP torque specification for that application should not automatically be assumed correct for a QG engine.

Fastener preload depends on the fastener, thread engagement, lubricant, engine structure and installation procedure.

For performance engine builds, this should be determined by a competent engine builder.

Head Gasket & Engine Condition

Upgraded head studs cannot compensate for other engine problems.

Correct cylinder head sealing still depends on factors including:

• Cylinder Head Flatness
• Block Deck Condition
• Surface Finish
• Head Gasket Selection
• Correct Assembly
• Cooling System Condition
• Fuelling
• Ignition Timing
• Boost Control
• ECU Calibration

Detonation or excessive cylinder pressure can still cause head gasket or engine failure regardless of the fasteners installed.

Manufacturer Warranty

This is a genuine ARP manufactured component and is supplied subject to ARP's applicable warranty terms and conditions.

Installation, inspection and reuse remain subject to the appropriate requirements for the engine application.

ARP is a third-party manufacturer. GizFab Motorsport Developments is an independent retailer and is not affiliated with, sponsored by or endorsed by Automotive Racing Products, Inc. or Nissan Motor Co., Ltd. Manufacturer and engine names are used solely for application and compatibility identification.