[Half Breed]

Can someone highlight the differences between the two for me, I have the basics down so do not be afraid to go a little more in depth (ie.. Ramp rates and such.)
Thanks in advance for the help

[Ratchet]

The main difference between a roller cam and a flat tappet cam is that the roller allows the cam to have much steeper ramps. This is possible because the roller does not have a sharp corner like a flat lifter. The ramp on the flat tappet cam must stay below an angle that will allow the face of the lifter to remain in conact with the cam profile. Too steep of a ramp and the corner of the lifter would dig into the cam.

This being said a roller cam with the same lift and duration can have much more flow due to the area under the curve being larger.

Ric

[NOlowrider]

Other than a roller cam and roller lifters, what else is needed to convert from flat tappet to roller. Don't mean to hi-jack. Just curious.

[steve392]

Another thing that may need to be addressed is the valve springs. Usually higher valve spring pressures are required with a roller lifters to keep them seated and following the cam profile. The cam manufacturer you select should be able to advise you on the correct springs to use.
A side benefit of this would be that you'll be able to rev higher before valve float.

Steve

[xntrik]

http://www.iskycams.com/techtips.php#2005