Absolute CNC Products – Copper Exhaust Gasket (O.S Engines)

O.S. Engines 61 / 70 / 91 / 105

The Absolute CNC Products Copper Exhaust Gasket is engineered to provide a reliable, high-temperature seal between the engine and exhaust header on popular O.S. nitro helicopter engines. Manufactured from precision-cut annealed copper, this gasket offers superior durability and conformability compared to traditional fiber-style gaskets.

Designed for demanding 3D flight and high-performance nitro applications, the copper construction withstands repeated heat cycles while helping minimize exhaust leaks, oil residue, and tuning inconsistencies.

Features

• Precision-cut annealed copper construction
• Excellent resistance to extreme exhaust temperatures
• Provides a durable and reliable exhaust seal
• Helps reduce exhaust leaks and residue buildup
• Reusable when inspected and properly maintained
• Ideal for high-performance nitro helicopter applications

Specifications

• Material: Annealed Copper
• Thickness: 0.010" (0.25mm)
• Finish: Raw copper

Engine Compatibility

Compatible with the following O.S. Engines:

• 61SX-H
• 70SZ-H
• 91HZ
• 91HZ-PS
• 91HZ-R
• Speed 91HZ-R 3D/3C
• 105HZ
• 105HZ-R

Installation Notes

Ensure gasket and mating surfaces are clean and free of dirt, oil, or debris before installation. The gasket may be installed dry without sealant. If sealant is preferred, apply only a very thin layer and avoid excess material entering the exhaust port.

For additional sealing assistance, Lucas Red ‘N’ Tacky grease (or similar) may also be lightly applied during installation.

Because annealed copper is soft and conformable, handle the gasket carefully to prevent bending or deformation prior to installation.

Proudly offered by Absolute CNC Products for enthusiasts who demand dependable performance and precision-engineered components.