Pros and cons of solid lifters?

Hydraulic lifters are subject to this thing called "hydraulic intensity" which limits how quickly the cam can open the valve without "collapsing" the lifter mechanism (which would be detrimental in terms of performance). With a solid lifter, the cam profile can be more aggressive and can accelerate the valve off the seat and open it fully more quickly, resulting in "more area under the curve" (more valve opening during the same period) than is possible with a hydraulic. This is why solids will make more power, and you can turn them more rpms because the hydraulics can start to have problems at high rpms. Because of the difference in ramp rates on the camshafts, in general it's not wise to put hydraulic lifters on a solid lifter cam, and vice versa


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