Hello everyone. Figuring fairly straight-forward job of changing the valve cover gaskets to fix typical chronic oil leaking on my white 1978 bus. However, there is quite a bit of jet-black, rock-hard burned oil on the valve cover "face" that the gasket sits on. I just have to believe if I leave it there, I'll never get a decent seal. I've attacked it with brake cleaner (no effect) and several engine degreasers. I'm brushing away till my arms hurt with a brass brush (to not scratch the valve cover) and letting the cover soak in degreaser for 15-20 minutes at a time in between each attack with the brush. I've now done this cycle 4 times and while clearly, I have removed some of the black burned on stuff, the lionshare still remains. I suspect if I kept this up for a day or two, I'd eventually removed it all, molecule by molecule but surely there is an easier way? I wondered if oven cleaner would work or if it might damage the metal surface, just being aluminum? I don't have access to a sandblaster (or glass blaster) or anything like that. From everything I've read, people are against putting in a layer of gasket maker to help seal it so I don't want to do that either.
I've attached a picture. I realize most valve covers have all that black inside the cover itself and I'm not particularly worried about cleaning that. What I want to do is get rid of that black burned oil from the actual edge face that the gasket goes on.
Anyone have a magic cure or at least a chemical that eats it/loosens it better than regular old engine degreaser?
Thanks!