This is pretty cool. When I was younger I built a mini engine (from a kit[1], I wasn't fabbing components) which gave me a nice intro to the basics of how a car engine operates, but whilst parts of it are pretty simple to get it's helpful to see the process.
Even if it's a monolithic gif that annoys web developers. Or if it only shows one kind of engine design.
I had that same engine you link to as a kid except mine was orange instead of blue. It's definitely one of my more memorable childhood toys and even though a fairly basic representation of an engine, I agree that it was a great intro. On a side note, I remember the screwdriver that kit came with was ridiculously bad. It made stripping the included screws really easy and made putting together the model more of a chore than it should've been.
Even if it's a monolithic gif that annoys web developers. Or if it only shows one kind of engine design.
[1] http://www.scientificsonline.com/smithsonian-gas-engine-mode... is pretty close, but mine was a bit more basic. 15 years seems to have improved science kits a bit.