Let's just talk about what's in the little Cessnas for now:
A Lycoming engine is what they call "boxer motor" in Europe. The Americans call it horizontally opposed cylinders.
For example a "O-360" means opposed cylinders, 360 cubic inches.
an "IO-360" would be an injected engine w/ opposed cyl. . . .
helicopters usually run HIO-360's and so on and so on . . . .
they are basically tractor engines from the 50's. Huge, but keep running.
Two sparkplugs in each cylinder, each plug runs of a different magneto.
(one magneto runs the top two plugs on one side and the bottom two plugs on the other side)
That helps the fuel burn better when they are both working and puts in redundnancy in case one magneto fails
They also have two mechanical vlaves in each cylinder. And, yes, they need to be checked and re-set periodically.
Each cylinder head can be removed and repaired individually. It's a very simple engine once you take a close look.
There is no cylinder block. Since the engine is aircooled (needs fins around each one of them) you don't need one and this way you can fix
individual cylinders pistons and rings without removing and replacing the whole engine.
Lubrication is what they call a dry sump I believe. The oil reservoir is in the bottom (square block, you can see it on the picture)
and the oil gets sucked to the top, runs trough the cams and so on until it drips back into the reservoir.
Yes, most have oil coolers, but the cylinders are aircooled.
The reason why the engine shook when it was shut down is a combination of the prop directly running of the driveshaft
and this engine having a huge amount of cubic inches as compared to a European car.
Most of them have only one fuel nozzle per cylinder.
Did that answer all your questions?