Pistons are another thing i saw at the workshop i had my industrial attachment. I never knew there are different types of pistons till i came across this.

I hope the one in the car engine isn't different from those of the diesel engine?
If they are then my imaginations have been wrong. We used the trunk piston at our workshop for those generators. Fixing a piston was a very hard thing. I still find it difficult to press the rings to make them fit into the cylinder. In case you are wondering, i repair our home generators and when it comes to cylinder problems.. I call the experts. 😂😂