Ok it does have a home.  It'll be going to Texas, for good purpose. 

It's really first come, first serve.  Best bet seems to be from Texas.  I can wait a bit for it to go, so no incredible rush.  

  I have a Power Line 12/1 1000rpm I purchased several years ago to go over and make into a generator set.  My back has been bad for about 13 years now and it's obvious that I won't be able to get to it.  This one will need to be gone through for sand, voids (flywheels), idler gear and rocker arms plus what ever has degraded during the sit time.  It includes the engine, muffler, flat belt pulley and manual/tools set.  If you can pull up in front of my carport and load it up and drive away, it's yours.  I want to see it go to a home where it can do some work.  I'm in North Central Florida. 

  Since you say the bubbles seem to appear when the thermostat opens it might be that they are collecting just above the thermostat in a cavity in the head.  Then when the thermostat opens they are sucked out with the water flow.  If that's the case it's probably nothing to worry about, EXCEPT, what's causing the water to get hot enough to boil?  Adding something to increase the boiling temperature might help.    Les

     If the big end had pressurized oil feed, the rifle drilling would allow the oil to move to the small end and lube it. 

  Thinking:  1) You use the higher compression to start because a higher compression produces a higher temp in the combustion volume, then drop back to lower compression to run.  2) Running under higher loading maintains a higher combustion volume temp. than lower compression.  3) Running at higher compression under light loading or lower compression at high loading keeps carbonization down.  4) I see that a lot of the smaller high speed diesels are running at ratios not much over 10:1 (say 11:1). 
   It would seem the determining factor is the actual temp. in the combustion chamber.  The higher the temp the less the carbon.  I think most of us would agree that any engine running under a full load gets a lot hotter then one running at a gentle idle.  So the real thing to aim for is to maintain the higher temp without letting it get too high [melt the piston]. 

  You could pipe the starting air into the inlet manifold close to the head.  Then place a oneway checkvalve just outside the air feed point (might want to use one with twice the area as the intake to give no resistance to flow).  When the engine is running the checkvalve would stay open allowing air to flow into the head.  When cranking, the cranking air pressure would shut the checkvalve and direct the pressure into the cylinder. 
  All you would need then could be a external cam running at 1/2 the crankshaft rpm that would open an external valve to supply the starting air.  Cam could be something small (size of a camshaft cam) or something big like a steel/iron plate that is milled concave or convex (depending on opening direction) to actuate the air valve.  And then something to bring air control valve into contact with cam when needed.  The big ship engines have a valve in or near the cylinder,  this would be outside the cylinder.  Also the proper timing on the external cam would have the intake valve open when you were injecting the starting air. 

  Grease is actually a carrier for the oil that does the lubing.  Early greases were simply clay saturated with oil.  The idea is that the oil will slowly wick out of the carrier into the bearing space, same idea with using felt to hold oil that slowly wicks out.  You don't actually need the grease to penetrate the bearing space just be really, really close to it.  Going with that idea it might be suitable to remove the grease cup and replace with a cup containing felt/fibers (like cotton waste) and just re-saturate as needed.