Core tomatoes and cut into 3 cm chunks. Place in a stainless steel or enamelware saucepan. Add water and sugar. Bring to a boil over medium heat. Lower heat to a simmer. Cover. Cook 2 hours or until tomato bits are very soft. Place mixture, one third at a time, in blender or food processor. Process until smooth. Mixture can be frozen. Serve tossed with pasta.