The MGC alloy head updated casting has now been heat treated and is on its way to the machine shop. Plan is to machine on the new CNC unit and this should be the final form for all following heads.
The main problem was wall thickness around the plug, the walls are thin even on the cast Iron head so for the first test head I used a 10mm plug. We have increased the wall thickness to the maximum without spoiling cooling round the plug.
We intend to continue to use the 10mm plug which comes in all heat ranges as required for longevity of the casting this is the way to go. I am sure that at some stage someone will over torque a plug and will need to repair, the extra meat around the plug will allow this.
A new set of valves has been made for us to use which will be a nice improvement in flow.
The amount of effort involved in bringing a alloy head to the C community has been huge on all parties from Steve and I to our caster, machinist and finisher. In taking our time to get it right we will ensure that the C will have a replacement cylinder head for many years to come.