eBay 4 million reasons you'll find it here
 
    Well I won't repeat my whining about the cylinder shims from Garage 6, but lets just say that we never got the right parts and the seasons were passing so I took matters into my own hands. Besides, where there is an aluminum cylinder head, a grinder, and me, chips usually a'start flyin'! The stock VW combustion chambers are not a very efficient shape. They're flat with sort-of oblong depressions where
the valves are. The flat, high "squish" areas cause increased detonation among other problems. Most combustion chambers in modern cylinder heads are shaped more like a dome. You can get air-cooled VW chambers cut this way also. It's called semi-hemi "semi-hemispherical". Gene Berg even sells the tool for machine shops to use to cut them.  I looked at the tool, I looked at my hand, I looked at the tool again, I looked at my hand again.  It started moving back-and-forth, as if guided by an instinctive - we can do this ourselves and not have to pay anyone - reaction, in a quasi semi-hemi wave.  Of course!  "Porter!"  I shouted.  "Where's my dust mask?"
 
    In addition to the more efficient shape, grinding the chambers allowed me to take off material that would lower the compression ratio to where we needed it to be (about 7.2:1) without any need for those blasted cylinder shims! Of course we had to check them several times until we had just the right amount of open area in the chamber. That is - we had to check each one...several times.  This was done by greasing the edges of a piece of
plexiglass, cut round to fit into the head just like the cylinder would, and injecting vegetable oil into a hole in the plexiglass until the chamber was full. By using a syringe to do this, you can measure how many Cc's of oil went in.  In gear-head speak it's called Cc'ing the heads.

    Occasionally, if Tracy is looking just a bit too contented & relaxed at the beach, in that dreamy half-conscious state, I will sometimes whisper into her ear in an urgent tone, "Chamber Volume!" or "8 cc's more!" Immediately after which, any rapid eye movement immediately ceases, replaced by violent twitching of the corner of her upper lip. Of course the old standby, "Valve adjustment!" still works pretty well too!
 
    Tracy runs a die on the head studs to make sure they're in good shape for reassembly.