Comments by "Mikko Rantalainen" (@MikkoRantalainen) on "" video.

@emrahayaz3207 I don't think this kind of forces are important even for high rev engines because the max force is during the intake stroke and there the max pressure is -1 bar which is nowhere near the forces in this test. In all other cases the piston will be under pressure. Too high RPM typically causes valve float and valves hitting the top of the piston. This test is basically measuring how much over-engineered the rods are in this direction. Without bearing failure, they will not fail in this direction in real world.
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@thomaskarlstrom4815 I think the G forces depend on the stroke length but ballpark figure for 8500 rpm should be roughly 5000 G, so a piston + rod weighting e.g. 700 g has weight on the cam around 3.5 tons. However, I think the actual weight is less because part of the forces are against pumping losses which reduces the effective weight on cam but it is still high force indeed. And it's easy to understand why removing e.g. 100 g from each piston might help a lot.
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