As of 2004, the gaskets hadn't been 'improved' in any way I can see. The elastomer (is it silicone, or something else?) simply peeled off the metal exactly as seen (yet again) in Kaiser's photo. The are many HG failures with exactly the same cause.
As for the OAT debarkle. I'm waiting to see the effects of 50% OAT on the elastomer that peeled of my own gasket. Obviously, immersion in OAT at room temperature isn't the same as the hot/cold environment of an engine, but if there is a chemical instability, it WILL show eventually. Chemical reaction rates double (approx) for every 10°C rise in temperature, so given enough time, if OAT dissolves/plasticises/etc the polymer used here, it will become apparent. After six months I see no effect. My feeling thus far is it's an adhesion problem. Perhaps OAT compromises the adhesion bond energy rather than the polymer itself? I bet Kaiser's engine (above) didn't have OAT in it??
TC
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