Ferrocarril General Belgrano (FCGB) 4-8-2 No 1802 that was the guinea-pig for several of Porta’s trials and experimentations between 1969 and 1974. It is referred to several times in the text of this Tribology paper where it is describes it as having “fairly high superheat (~400oC), steam pressure 14 atm, and working speed ~40 km/h (~170 rpm)”. Its many modifications included high temperature superheat; improved valve and piston rings and "between the rings” lubricant feed.
The loco was also the first locomotive to carry a fully developed Lempor ejector (see Matyn Bane's website), and was subjected to extensive testing of Porta’s water treatment system.
The above photo (by Richard Campbell) is taken from Porta's Manchester Paper as published in Advanced Steam Locomotive Development published by Camden Miniature Steam.