Compact Graphite Iron (CGI) Casting Stage 6 Cylinder Head For Cummins ISX15 Engine

Upgrade your Cummins ISX engine with this high-performance Compact Graphite Iron (CGI) Casting Cylinder Head, built to outperform standard cast iron heads in strength, thermal conductivity, and durability. Designed to meet or exceed OEM specifications, this CGI cylinder head offers superior resistance to thermal fatigue and mechanical stress—ideal for heavy-duty applications.

Cummins ISX15 Cylinder Head Casting # 4298234, 3688754, 3687398, 3686431

Serial Numbers: 79438920, 79457900, 79469386, 79527893, 79575425 & More

OEM Part # 3686431, 3686432, 3686434, 3686660, 3686660NX, 3686660R, 3686774, 3686880, 3686881, 3686881NX, 3687398, 3687607, 3687607NX, 3688754, 3688800, 3688800RX, 3691250, 3691253, 4298234, 4298235, 4298237, 4298237NX, 4298237R, 4298238NX, 4298238RX, 4356434, 4356434NX, 4356434RX, 4374091RX, 4386009RX, 5628269, 5628269RM, 5628269RX, 5658294, 565829400RX, 5658294RX, 565830100RX, 5658302, 5658302RX, 5658309, 5658309RX, 5708760, 570876000RX, 5708760NX, 5708760RX, 79438920, 79457900, 79469386, 79527893, 79575425, 4386009, 3688761, 3688761RX, 4374091, 4298238, 5394197RX, 5394198RX, 565829400, 565830100, 570876000, 5394197, 5394198, 3688759, 3688755

OEM Part Number

• Cummins Part Number: 4386009

Product Features

• Material: Compact Graphite Iron (CGI)

• Configuration: Fully assembled cylinder head (valves and springs included)

• Inconel Valves Intake & Exhaust

• Fire Rings

• Casting Type: Precision machined for OE fit and performance

• Application: Designed specifically for Cummins ISX series engines (ISX15, ISX CM871, CM2250, CM2350)

• Design: Advanced metallurgy for improved strength, heat resistance, and fatigue life

Material Benefits: Compact Graphite Iron (CGI)

• Higher Strength-to-Weight Ratio: Approximately 75% stronger than traditional gray cast iron.

• Improved Fatigue Resistance: Ideal for high-stress diesel engine environments.

• Superior Thermal Conductivity: Enhanced heat dissipation helps maintain optimal combustion temperatures.

• Crack and Wear Resistance: Reduces the chance of warping and cracking under extreme load and heat.

CGI material isn’t just marginally better than traditional gray iron – it’s a revolutionary improvement:

• 75% STRONGER than conventional gray iron
• 70% MORE HEAT TOLERANT for superior performance in extreme conditions
• 25% BETTER THERMAL CONDUCTIVITY for improved heat dissipation
• 35% MORE ELASTICITY to resist cracking under pressure

The unique graphite structure in CGI creates an interlocking matrix that suppresses crack initiation and impairs crack propagation – exactly what your high-stress diesel engine needs for extended service life.

Benefits of Upgraded Inconel Valves

The upgraded Inconel intake and exhaust valves offer several performance and durability advantages over conventional valves:

• Excellent resistance to extreme heat and thermal fatigue
• Improved durability in high-temperature diesel applications
• Better resistance to valve cracking and burning
• Enhanced performance under heavy load and towing conditions
• Increased reliability for commercial and industrial use
• Ideal for engines operating in severe-duty environments

Inconel is a premium high-temperature alloy commonly used in performance and heavy-duty diesel applications where standard valves may fail prematurely due to excessive heat exposure.

OEM Compatibility

This cylinder head is a direct OEM replacement for Cummins ISX engine part number 4386009. It is precision-engineered to meet OEM quality and performance standards.

Compatible with:

• Cummins ISX15

Why Choose a CGI Cylinder Head?

Compared to traditional gray cast iron heads, CGI heads offer:

• Longer engine life

• Increased load-handling capability

• Reduced risk of head gasket failure

• Better emissions performance due to improved heat management

CGI Popular Uses in Diesel Industry:

Compact Graphite Iron is increasingly used in diesel engine blocks, especially for engines that must withstand high combustion pressures and thermal loads (like Cummins and Navistar heavy-duty engines). It offers a balance between the high strength of ductile iron and the thermal performance of gray iron.

FAQs

What is Compact Graphite Iron (CGI) and why is it better?

CGI is a material that offers superior tensile strength, heat resistance, and fatigue durability compared to gray cast iron, making it ideal for high-output engines like the Cummins ISX.

Is this head compatible with all Cummins ISX engines?

It is compatible with ISX15, CM2250, and CM2350 series engines. Please confirm with your engine serial number before purchase.

Does the head come fully assembled?

Yes, this cylinder head is fully assembled and ready for installation. It includes valves, springs, and all major valvetrain components.

Can this cylinder head be used in performance or tuned ISX engines?

Yes, due to its increased material strength and thermal properties, it is ideal for both stock and moderately tuned ISX engines.