I need to replace o-rings in an old OS glow engine. I can find a variety of o-ring sizes and materials from a local o-ring supplier. However, I am not sure what is the best type of material which is fuel and heat resistant. Any o-ring material info will be appreciated !

The stanard black 'O' ring material is, I think, Buna-N. This is fuel resistant to glow fuels. I am not sure about other fuels. For high heat applications use rings made of 'Viton'. I am not sure if Viton rings are available in all sizes.

Ed S

I've borrowed o-rings from old disposable butane lighters to tighten up wiggly needles, none has ever suffered any ill effects from glow fuel that I have been able to see.

Material . General Properties . Common Applications

Buna-N
(Nitrile / NBR)
70 Durometer Black

Good resistance to petroleum, hydrocarbons, fuels.
Widely used with most oils, hydraulic fluids, alcohol.
Poor resistance to sunlight, weathering and ozone.
Many compound variations for specific applications.
The least expensive most readily available material.
Basic temperature range: -40 F to +250 F*

Petroleum Oil Seals
Hydraulic Fluid Seals
Water / Greases
Transmission Fluid Seals

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Viton®
(Fluorocarbon)
75 Durometer Black

Excellent temperature and chemical resistance.
Excellent mechanical and physical properties.
Low compression set and low gas permeability.
Not for use with Acetone, Skydrol, or ethyl Acetate.
Basic temperature range: -20 F to +400 F*

Vacuum Seals
Many Acids and Fuels Heat Resistance
Many Chemicals
Many Solvents

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Here's an exerpt from a website giving excellent info on Buna-N and Viton. Buna-N seems to be a lower cost alternative and meets glow engine requirements well. Thanks folks !