I don't know how you figure the TES seals could raise the temp but I am concerned at how stiff they are and in the application of the rotors I think the seals need to be softer and more flexible but that's just an eyeball engineers point of view, the Viton seals have worked just fine for me and in my early days of sorting things out I was running very high oil temps and still had no problems with the O-rings, if it works I don't fix it.

 I am however using the TES O-rings in the rotor housing and like them and will stick with them but this is an application where I don't think they need to be flexible as with the rotors but then again I am just an eyeball engineer.

  Ken Welter

Ken,

When rebuilding my 20B, I used TES o-rings on both water and oil.  I have a little over 9 hours of light running (ground runs only) on the engine with no apparent problems.  The one thing I think we need to realize with the oil o-rings is their proximity to the very hot rotor surfaces.  Lynn has stated that under heavy loads the rotors can get to 450* or higher.  Since the oil o-rings are in the sides of the rotors, very near the hottest part of the rotors, I suspect they could easily see temps higher than what we’re reading on the oil temp gauge.  I don’t recall seeing any temp figures that have actually been measured for the oil o-rings.  I don’t know how we could measure that, but if we had that information it could answer the question of whether or not TES oil o-rings are needed there.  I figured it was cheap insurance, so I used the TES o-rings for both the oil and water locations.

Mark S.