CNC porting of Porsche 911 air-cooled heads is something we do a lot of. Everything from mid-1960’s to late 1980’s heads. We supply a lot of engine builders with heads for these. Seat and guide replacement, welding of damaged heads, CNC porting, hand porting, manifold matching, all sorts. Whether it is a 2-litre control spec or a huge valve 3.6-litre build you require it’s not a problem.
Here are 3 stages of repair to a blown up 911 cylinder head:
The damage to the head is tig welded
The excess material in the bowl is then machined by CNC
The seat inserts are fitted, profiles cut and top faces decked to precise heights