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</o:shapelayout></xml><![endif]--></head><body lang=EN-GB link="#467886" vlink="#96607D" style='word-wrap:break-word'><div class=WordSection1><p class=MsoNormal>When I rebuilt my engine, in order to try to prevent the well documented leak from oil to coolant for which a repair kit is available, I first had my block cleaned (dipped in I know not what for a week) followed by resin vacuum impregnation. For the UK see <a href="https://www.midlanddeburrandfinish.co.uk/casting-impregnation">https://www.midlanddeburrandfinish.co.uk/casting-impregnation</a> but I am sure that similar is available in the USA.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>This process has the significant advantage that all surfaces of the block are effectively resin coated, and the water jacket no longer corrodes, improving heat transfer to the coolant. However, the dimensions of the block are not altered – my cam followers run in the original bores without any machining. My block was rebored after the above processes, and at least honing would be advisable.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>The snag is of course that the engine must be completely disassembled, and all copper/brass parts are destroyed by the dipping process. Cam bearings must therefore be replaced. I removed my main oil gallery plugs before dipping, and they are replaced by screwed plugs sealed with the appropriate grade of Loctite.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Ian<o:p></o:p></p></div></body></html>