Tractor Repair: Engine wont move, allis chalmers, main bearings

Question
Hi

I am working on a Allis Chalmers B and can't get the engine to move. I have tried putting Marvel Mystery oil and letting it soak for about 6 months is there anything else I can do to get it to move.

Answer
Hello,

  If the engine is just stuck from sitting a long time, filling the cylinders with penetrating oil and letting it soak usually only takes a few weeks for it to break free.  6 months is a long time.  Not knowing the history of this machine, it's hard to say what could be wrong.  If you bought this from someone that told you the engine was just stuck, it's possible that there is more wrong internally such as a spun bearing.  I would suggest removing the oil pan and checking if you can move the connecting rods back and forth on the crankshaft.  The rods should have some end play on the journal.  To check the main bearings, you should be able to pry the crankshaft forward and backward a slight amount because of the end play on the thrust bearing.  You could also unbolt the connecting rod caps and see which pistons are stuck and try to break them free individually with a hammer and block of wood.  If the engine filled with rain water from sitting outside with an uncovered exhaust pipe, it could be so severely rusted that no amount of soaking will break it free.  I have a parts tractor that filled with water and froze and broke the sleeves.

                       Good luck,

                            Arnie