It's a tiny engine.
The rings are (according to the instructions) matched to their cylinder bores, and if anything one is supposed to make sure that the rings stay with the liner they were in at delivery.
But in intself, the rings slipped very easy around the pistons, and appear to be loosely fitting in the slot, sticking out quite a bit. There is a relatively huge amount of ring tension against the liner, and despite the conical ringcompressor, the pistons were fairly hard to get installed in the liner, and the rings caused quite a bit of drag, despite using lots of oil at assembly.

This thing runs, and I am sure it does make a LITTLE bit of effective power as is (mind you, it is designed to run 25~30% Nitro, but I am just using gas). But the intake manifold is a disaster WRT design and flow capability. I think I can make HUGE improvements there, if I manage to re-do that.

As it is now, the cylinders 1-4 are connected to one carb, and 5-8 to the other.
The nasty thing is that cylinders 1, 2 and 3 are drawin mixture within 270 degrees of each other, then there is a pause, and cyl 4 is drawing in mixture without any interference of other cylinders. This has to happen through extremely narrow bores in the intake distributor. So narrow, that the "central bore" that connects the 4 branches to each head, is allready restrictive for ONE cylinder, let alone 3 or 4. THis whole situation causes a very uneven mixture strenght to each cylinder. The thing needs to be very rich in order to have the leanest cylinder rich enough to fire. It GUZZLES gas (even gas, yes...) and the exhaust stinks to high heaven.

Due to the firing order (which is also induction order of course) I will need to group cyl 1, 4, 6 and 7 to one carb in order to have one induction stroke evenly spread every 180 degrees of crank rotation. That will provide much more even mixture strenght.

That is going to take quite a bit of effort because of the physical shape of the manifolds...