Thought it might be interesting to post the picture below as it very clearly illustrates the porosity problem on the fire ring encountered on K series heads. This type of problem inevitably causes breaches across the fire ring and although I have a large number of documented cases the picture taken here is very clear and unequivocal. Sometimes it is difficult to get the camera to focus well enough to make the breach clear.
So is there any rhyme or reason attached to this issue - building a list of heads that might be expected to have problems or maybe types of heads that should be clean?
It was just an illustration of something that has been discussed and denied here a few times. In my experience, heads cast between 2000 and early 2002 exhibit the worse porosity, pre 2000 and post 2002 seem a lot better.
Thats pretty much what I had heard - 2000 to 2002 the ones to avoid.
I think the case for porosity in the heads was pretty much black and white to everybody bar one notable, if barking mad, exception. It was good to see such a good photograph of the issue though.
Amen to that… the evidence I have here is pretty convincing, there is a lively discussion on SeLoC regarding possible solutions and avoidances, by and large it is a productive one too.
