patrickt Pat 1/2 of the reason hydros roller last longer is because of the lash load on the lifter all the time. The wheel has consist contact with the cam shaft, even on the down side of the lobe. The
oil acts like a cushion to help extend the life. With a solid camshaft setup roller or tappet you have a .018"-.025" of space that is either between the lifter and the pushrod or the pushrod and the rocker adjuster. This clearance is what causes the roller lifters and solids to wear out. Oiling does have some to do with this. If you put a rev kit in the motor you remove the lifter bouncing over the surface of the camshaft lobe. this will stop the beating of either the bearing inside or the wheel. The other side of the problem is how much spring pressure is need ed to control the lifter at say 6,500 rpms?? I am looking at using the weakest spring for a rev kit and seeing where this will go. If this works, you can run a liter valve spring and get the same or higher rpms without floating or hurting the valve train or motor.
The other problem, IMO is oiling of the system. IMO when a motor is running at 2,000 rpms there is enough splashing inside the motor for the camshaft and lifter contact points, (MAYBE) depending again on the block. By adding a small groove to each lifter bore or in some cases the new lifters have a groove in the outside case, add more
oil to the contact point of lifter and lobe. The idling of solid lifter motor is what kills there life. I have some ideas for my other motor that I will get the test to see if my theories are right or not. I am staying with a hydro lifter motor and looking at a rev kit.
With the amount of power hydro roller motors are making, unless you are looking for every last rpm in a motor, I just don't see the need for 7,000 rpms on the street. You build a car with the right gearing in both rearend and trans, have a motor with a large torque power band, it will live twice as long, require less maintainance, and is not extended beyond there limits of this FE block.
Just my 2 cents.
