today I emptied old oil from my engine. I pretty sure that old oil was resting inside engine at least for 15 years (Yes.. engine was idle about 15 years).
althought engine is in very good condiction, old oil became solid at the botom of engine (don't know the english name for that part).
I used wd40 to clean all 8 cilinders.. I hope no one pinston rings locked after wd40. I will let it rest for some days. then, I will paint engine with a bright orange