what is the reason or is there any benifit in a solid roller engine?
Why do they do it in flat tappet engines?

 

They do it on flat tappets because it lets them run a more aggressive lobe, the roller lifters we got stock are a big step beyond that already.

 

By increasing the contact area of the lifter, there was less pressure on the surface of the lifter. The reason behind this is because Pressure=(Force/Area). Even if you still had the same cam profile (only applies to flat tappet), by increasing he contact area with a constant force the pressure will decrease. But like mentioned above, you are already better off with a roller cam.

 

Yes,

The benefit in a solid roller motor, or the reason I use them is that it makes my lifter bore indexing easier to do. You don't have to bush the block most times. You can also get some strength increase in the lifters doing this, but mostly for the lifter bore indexing is why I would do it.

Bret