On the V-8 kits I built they weren't too bad except for the Distributor, the gears were poorly made and it was difficult to get them to mesh for long so the "Plugs" didn't fire right, if at all.
No big deal, when I was a kid I pretty much thrashed my toys, over-revving them much like the guy on YouTube does but without the oiling system.
The Main Bearings melt to the Crankshaft pretty quickly when you're running it off a Drill without any lubrication!
