Any one know for sure what material injector O-rings are made from?

With the use of E85 fuel I wonder if they are using Perfluoroelastomer (Kalraz, Simriz) compounds.

Yes..they are rubbery like compound

I believe they're made of Viton.

When you say "With the use of E85 fuel..." do you mean in general for some vehicles, or do you mean in your Bonneville? 'Cause I'm pretty sure ours are not flex-fuel.

I assume you mean in general. I do know that GM will use different o'ring compounds for different vehicles depending upon application. Most times they will spec a lower level, lower cost compound if the application doesn't specifically call for the more expensive compound. Just a general statement.

Lash

Yes some of the newer GM vehicles are supposed to be E85 ready and Viton does not like Ethanol.

It would be nice to know for sure what elastomer O-rings were used in our fuel system.

For example what are the o-rings made from on the AC Delco injector kit # 317-454.

They are probably made from one of these = Buna-N, Viton®, Neoprene.

It would be nice but unlikely that GM will use many of these $10.00 and up o-rings. = Viton ETP (Viton Extreme), Chemiz, Simraz, Kalrez.

Link http://www.allorings.com/material_selection.htm

Exactly what I am saying. I used to work for a company that made fluid delivery systems for OEMs w/GM being our largest account. In some cases, they wouldn't even pay the pennies per o-ring difference for a coated neoprene o-ring vs. a non-coated one unless it was required for the application.

Also, remember that for E85 use, you would likely need higher delivery injectors, as the fuel consumption is greater. That is one common feature of flex-fuel vehicles, a fuel system capable of a faster fuel delivery rate (pump and injectors).