Which style of cam gives the best port

velocity? flat or roller?

Still scared to bite.....
Hey blown what is the drink of choice tonight?

Maybe, I was thinking, thou I dont do it often. If a roller has such a steep ramp angle wouldn't it be more of a start/stop cam as far a velocity goes, where as a flat tappet starts the lifter earlier and gets the flow moving??
Whiskey seven, got to finish that bottle, it keeps calling to me.

Trying to do this with as little typing as possible:D
Many things determine port velocity as you know. When the valve opens in relation to the crank timing makes a big difference because of piston speed. As the crank rotates the piston speeds up then slows down because of rod angle and crank angle. Hypothetically if the valve opened slower at the same piston location, the port velocity would be greater than if the valve was open further, but cylinder filling might not be as good overall.
I'm not sure I said that very clearly.
**** it I need a drink. Been thinking about camshafts all day.
Going home now.

The right camshaft will take advantage of the heads potential, the wrong one won't. Thats why I stress it is important to build a combination, not buy parts and put an engine together.
chris