Some Land Rover engines have jets of oil played on the under side of the piston crown for cooling as I imagine do many other engines
Thanks for the info

. I don't remember seeing that kind of cooling solution. But here we go, my knowledge about engines is limited to small, model ones.
What comes to mechanical animations, like gear trains, there seems to be several ways to achieve desired results. One that I'm particularly interested, is using previously mentioned rigid bodies where several objects react to other ones in "physical" way. It may sound like I know what I'm doing, but it's trial and error process. Although there are, no doubt, very sophisticated ways to achieve expected outcome, those are for advanced users; I just prefer the 'hands on' approach instead.
It's sort of like playing with lego blocks. Animated and/or simulated objects can be modified to affect the result, like in this video, which uses same objects that were in previous video, with added elements. I didn't expect such a result, but it's actually going to the direction I'm after:
In the end, again some critique (not to blame by any means) about Blender:
- Its user manual has almost 6000 (yes, thousands) pages, but it's more like a reference, as there doesn't seem to be instructions that newcomer could easily follow (that's probably why Youtube has zillions of tutorials).
- Some functions (like object's properties, and how it shows in the viewport) are scattered around, and usually it takes search on the net to find out where, and which terms to look for.
- Preferences menu (especially 3D viewport one) is like wild jungle, having hundreds of options to adjust UI colors, which is actually very good idea, but to find the element one wishes to adjust is not necessarily that easy.
In the end, Blender might be a great tool to just play with.