Fred,I just wired a Sunnen engine cleaning system at the local auto machine shop.
The cast iron,block heads,whatever, is heated to around 800 degrees F,all the grease and water jacket deposits and rust is vaporized.Then an after burner incinerates the debris to 2600 degrees,only a hand full of dust left.Then the block is put in another machine if necessary,stainless shot is fired at the block,low velocity,not like a sandblaster,to clean any remaining crud.The iron parts look like the day they were cast.
These two machines cost about the same as a new 4x4 truck,but the shop doesn't have the hassles of all the nasty chemicals and disposal of those chemicals.
