mech Roller vs Mech flat tappet cam Q

tooslow said

RB"s have the large diameter lifter bore-.902 With this in mind would there be any advantage of going to a Mech Roller vs a standard Mech flat tappet in the .590 lift and 240 dur at .050?
The car is not a drag racer it is driven on road race tracks and consistantly in the 2500RPM to 6200RPM range

Click to expand...

All mopars have the largest factory diameter. The limit imposed by lifter diameter is rate of lift. That's it. Once you make the change to a roller tappet (solid, not a hydraulic roller tappet) there is no real restriction. So the exact same duration at .050, or at .200 lift, can still be an overall larger area under the curve with a roller lifter. If this is the oldschool .590 MP solid, there are major improvements over that just in solid flat tappet cams. If you want to post all the info on your build (including car, gearing, trans type, and P/S and A/C or not) we can help be more specific.
The "surface area" is really a non issue. Yes, technically, it's larger. But, it's not really relevant because the load capacity of the oil wedge on even the narrow Chevy lifter face well exceeds the force applied through the valvetrain by the springs.