i was wondering what the difference was between roller cams and flat tappet cams. also what the difference between hyd. and mechanical cams? thanks for the help.

 

A flat tappet can have either a solid or hydraulic tappet ( lifter ). The mating surface between the camshaft lobe iand the lifter is flat ( with a slight taper to it to create a spinning motion with the tappet ). A Roller cam means the tappet has a roller bearing that comes in contact with the camshaft at the lobe. A solid lifter ( either flat or roller ) has no internal moving parts and requires that a clearance be set between the camshaft and tappet to allow movement ( pushrod, etc ) to eliminate a mechanical bind. A hydraulic tappet ( roller or flat ) has an internal spring that works ( in combination with oil pressure ) as a shock absorber to eliminate the prevoiusly mentioned mechanical bind. The hydraulic tappet is adjusted to allow a slight amount of tension on the internal spring.

 

so basically that makes a lil sense. little confusing. which one is better?

 

Well I would say hydraulic rollers because for street driveability and the rollers because the free friction and creat less stress on an engine.

 

Which one is better?
racing..............mechanical roller tappet for the most power
cost.................hydraulic flat tappet
longevity..........hydraulic roller tappet
racing + cost....solid flat tappet
So, as You can see, there is no " best one " , There is a use and application for each depending on Your need. If You think about it, that sorta applies to everything in life. Cost versus need versus whatever and so on...............