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Skimming 12G295 Head
Posted: Sun Mar 27, 2005 8:59 am
by wanderinstar
Does anyone know what the most I can skim of this head, without going through oil gallery.
Thanks.
Posted: Sun Mar 27, 2005 1:21 pm
by bmcecosse
I answered you directly Ian - but for others to see - I have a head at 120 thou, but it is very thin at the water ways and the oil gallery has been brazed up. It does work though ! I would say 80 thou is the safe limit - but check by measuring down the vertical oil passage with a probe and compare that with the head thickness. It may already have been skimmed ! Better to use 12g940 head which has 21.4cc chambers - and so needs no skimming - but does need block pockets to clear the exhaust valves. Some say you can 'get away' with not doing pockets - it's very risky - but may be possible - depends on your luck, and on how much the exhaust valves have 'sunk' into the head !!
Posted: Sun Mar 27, 2005 8:58 pm
by Peetee
On the end of the 12g295 head there should be a cast 'button' about 3mm across which represents the safe skimming limit.
Posted: Mon Mar 28, 2005 5:27 pm
by bmcecosse
That's the hole where the oil gallery is 'plugged' - but it may not have been drilled absolutely parallel to the head face - it could be running slightly down to the face - so it's really essential to check down the vertical oil hole.