hi all,
Rebuilding my 1973,5 911 2.4 CIS, (using wayne's book) i ren into serious pitting in the combustion chamber of one of the heads...such a set back, i wonder if it's too much to ignore, and if so, how to fix it or deal with it....any help is much appreciated. I am rebuilding to a high standard so temporary fixing with pastes like JD weld is not really an option i guess. Note that valve stems and seatings have not been replaced but will be in any case, makes more sense to do that after fixing pits. (i used light glass bead blasting, i suppose the material where pitting came up was very weak). just for the fun of it a also attach the "before" picture of this head, shocking...
questions i have: 1)if i sand/polish/mill it away, do i affect compression ratio or geometry too much? 2)if i can find a welder, do i risk warping the heads? 3)if i buy a replacement head, i risk having a rebuilt one, i have one shallower head than the others so cam tower/chain housing will not fit.
thanks, jonas
PS the root cause of this i don;t know (maybe not important), can be either 30 years of grease soaking into the aluminium, or oil i used for rusty nuts that i applied for a week or 2 that turned out too agressive...
