Because the ratio is 1.6 to 1 it will be harder to push than a 1 to 1.5 ratio. It is simple leverage. a 1 to 2 lever is going to be twice as hard to push but travel twice as far as a 1 to 1 lever.
Thats why.
also even if the valves move the same with a bigger cam the higher ratio is still harder on the system.
