Steve, An absolutely fair comment and one which is all too often overlooked. Often, following skimming small cavities are exposed in the metal, if these are away from the firing ring then there is no problem, however if they coincide with the firing ring then the head is doomed to fail again. 'Peening' around the firing ring, re-hardens the metal and eliminated cavities before skimming. I also installed the new LMS gasket with SS shim. The shim was designed overcome softening of the head. Tim
The process is one which I learnt from Dave Andrews, K-Series Guru. It also worth getting a head tested for general hardness after a HGF. This is done with a specialist piece of kit which drops a ball bearing on to the surface of the head and an echo measured. All very clever!
I was quoted £95 for a skim and pressure test, and that was the best quote I had, decided to attempt the head gasket myself to save on costs, seems straight forward enough.
@superbran2008 Fair comment but I considered using the glass technique but was trying to avoid stripping the head. When I found the pitting there was nothing else for it but to strip it anyway and then for the cost of 30 quid a skim was quick and ease and guarantee the head would be square. I have another head stripped and read for a linnishing so will try using the glass technique on that.
sanding the head ??? use a pice of glass and grinding paste put the head on the glass and move in a circular direction thus skimming the head prosise and cheaply
Steve, An absolutely fair comment and one which is all too often overlooked. Often, following skimming small cavities are exposed in the metal, if these are away from the firing ring then there is no problem, however if they coincide with the firing ring then the head is doomed to fail again. 'Peening' around the firing ring, re-hardens the metal and eliminated cavities before skimming. I also installed the new LMS gasket with SS shim. The shim was designed overcome softening of the head. Tim
The process is one which I learnt from Dave Andrews, K-Series Guru.
It also worth getting a head tested for general hardness after a HGF. This is done with a specialist piece of kit which drops a ball bearing on to the surface of the head and an echo measured. All very clever!
One day I hope to post a video which demonstrates how to linnish (read sand down) the block in-situ to achieve the correct liner protrusion.
Tim
I was quoted £95 for a skim and pressure test, and that was the best quote I had, decided to attempt the head gasket myself to save on costs, seems straight forward enough.
@superbran2008
Fair comment but I considered using the glass technique but was trying to avoid stripping the head. When I found the pitting there was nothing else for it but to strip it anyway and then for the cost of 30 quid a skim was quick and ease and guarantee the head would be square.
I have another head stripped and read for a linnishing so will try using the glass technique on that.
Excellent vid!
Good video!!! I've got the same valve compressor, what size socket did you use?
Cuppa tea making at 4:07. :)
sanding the head ??? use a pice of glass and grinding paste put the head on the glass and move in a circular direction thus skimming the head prosise and cheaply
Great sequencing video. Very interesting. (Do you live at Heathrow?!)
No matter where you live in London you can hear the drone of commercial aircraft. Heathrow would be louder! :)
sorry for my very bad english but i would know if the head is peened before or after skimming ?
there is no problem of impervious after this ?
The head is peened before skimming. This hardens (compresses) the aluminium around the cylinder lining.
The head gasket is still OK after 6-7 years.