angled valve job

[123patrickquad]

what exactly does a angled valve job do.

[lafinrat]

I imagine you are talking about a multi-angle valve job. Like a 3 angle, 5 angle, blah, blah.

What that refers to is how many different angles are cut into the seats on the head. The benefit is increased flow as the seat becomes more 'round' instead of having sharp, abrupt angles. For simplicity we'll say the normal valve job has a 45 degree seat angle. That is the anglular difference between flat and the seat. A 3 angle would also incorporate a 30 and 60 degree cut. A 5 angle may use 15, 30, 45, 60, 75. The problem with too many angles is a smaller seat margin (the width of the contact patch between the valve and the seat). That's why multi-angles are sometimes only considerd on the intake seats as there is less heat in this area and the margin can be reliably smaller. Another trick that only takes a minute or so, is to cut a 30 degree 'backcut' on the valves while they're already chucked up.

BTW. Seat angles are a 'mystery science', and the preferred angles differ from engine to engine. It takes a lot of dyno time to figure out the best angles for each engine. Some builders start out on a flow bench and then back up their research on a dyno. We're talking anywhere from fractions of a HP to a few HP just by manipulating the angles. This is one aspect of a build that seperates the best from the rest.

[fitethesystom]

skip it bro move on .... skip it.