you might be interested in howacarworks.com. I stumbled across these videos on youtube earlier this year when I was researching the topic. I was unwilling to pay because it was more for my own curiosity than an actual need to learn but it seemed pretty thorough.
Man, that site has come a LONG way in the past couple of years. I haven't seen it since probably 2015. Back then, the diagrams were super useful, and the content easily understandable. Now it looks like a Mechanics University!
