Those blue things by the tyres are the air intakes. The engines look like 100cc - the ones you used to find on Formula A karts until they went water-cooled.
With a lot of redundant parts and extra weight and tranny friction and no scavenging and, and... four single cylinder engines are probably just going to be four times as rough, too, instead of much smoother.
If you spent a lot of money, maybe it could be done well, if impractically, but this is just...
It's going to be a bit less than what a 4cylinder could do.
No, if you look at an engine cut away, only 2 cylinders fire at the same time on most 4cylinder engines... 1 exception being Audis 1.8T (the Audi engine fires 1 cylinder at a time) every engine cylinder that fires, has an alternate cylinder firing at the same time unless its a 1cyl engine or a 2cyl engine.
What? 4 cylinder engines have one cylinder firing at a time. e.g. over 720 degrees of the engine, the firing order might be 1, 3, 4, 2, every 180 degrees.
It's been like that since about 1885 to 2007. Some cars might have wasted spark ignition (so the spark plug will fire at the top of the exhaust stroke, but it doesn't give any power, just simplifies the ignition system, and can clean emissions slightly).
Not all 4cylinder engines fire individualy Tristan. I have seen a cut-away where the 2 outside pistons and the 2inside pistons fire as a pair not individually.
And I thought it was over 360 degrees of rotation?