Once the guides were gone and the valves were out of the way, I was powerless in the face of temptation and succumbed (again) to the "while we're in there" syndrome.
As such, I had Jason (VintageVolks) do a "fluff-n-buff" (insert sophomoric joke here, Jethro) port clean-up. Panchitos come with very well designed "as cast" ports-- they're meant to be ready to go without any porting. Indeed, there's almost no extra material in the casting to remove if a guy DID want to port them, and what makes them so magical is that they flow ridiculously well with a very small port. This is what the "as cast" ports look like:
There's really nothing to be gained by messing with the ports, but the theme here is "why leave well enough alone?", so we (I) wanted to just remove the casting flash-- no reshaping or enlarging of the port walls, but just a clean and deburr.
Before anybody says anything-- yes, I know the intake needs some surface character to keep the mixture in suspension, but taking it to this level should have no negative ramification. I was going to have VintageVolks put a mirror finish on the chambers and exhaust ports (not for flow, but so that carbon doesn't stick as readily), but stopped the process before it got out of hand (see @Panhandle Bob-- I can stop any time I want to!).
This is what we've got with a bit of 80 and 120 grit and a die grinder:
We're nowhere near done yet. The new guides will be installed (the heads heated and the guides chilled-- Jason shoots for a 400* temperature delta) and cut for the seals.The heads will be flycut to 56 cc chambers to get 9.9:1 CR with .040 copper head gaskets (assuming 0 deck). If this proves to be too much, I can get back to 9.4:1 by swapping the .040 gaskets with .060 gaskets.
Once the chambers CC correctly, Jason will do a nice 3-angle valve job, and we can turn our attention to the beehive set-up, and the Hoover modifications to the rocker arms.
Stay tuned for the next exciting episode...