Jhaynie,
I changed my
oil the first time at 400 miles per the engine builder and it just had a few traces of black in it. I then called and was told that is normal as no matter how clean the block was, there can be a little discoloration due to added
oil lines, coolers, filters, & etc. Since then I have never had any really black
oil, just what I would call normal as my driver car which is a stock 1965 Comet with a 289 and automatic has blacker oil in it when I change it then the Cobra does. I am not a chemical engineer but I was told that heat will cause some discoloration too.
Ron61
Ron Widener