Supposedly BMW did that to their turbo F1 engines in the eighties. They would have a bunch of blocks sitting out in the cold, and they would pee on them to age them. That and welding the cylinder head to the block gave them 1500 hp out of a 1.5 liter engine for one lap.
Wow, I honestly thought you guys were both trolling. From the article above comes this brilliant hack:
While some may laugh at this strange solution by the German manufacturer,
the urinating process is based on nitridization (a process which introduces
nitrogen into the surface of a material and is widely used in automotive,
mechanical and aeronautical engineering, having the property of a
case hardening treatment of predominantly steel but also for titanium,
aluminium and molybdenum). Why are we talking about nitridization?
Because urine seems to contain numerous waste compounds, many rich in
nitrogen. We can't yet figure out how the German engineers found this
particular method to strengthen the cylinder blocks – and not use a
more technological measure – but it makes for some interesting stories to
tell out grandsons.
Hah! I have some friends who had some beautiful (copper?) gutter pipes installed at their house. The metal had a wonderful worn look to them. When I asked how they got it that way she replied that her partner had peed all over them for some time. I've never heard of it before but it seems true.
http://www.autoevolution.com/news/turbocharged-engines-in-fo...