What is a three angle valve grind?

[TexasJ10]

Several times lately I have heard that a three angle valve job is desireable during a head rebuild. What does this mean and how do you know if they did it when your heads have been rebuilt?

[xj2fsj]

A three angle grind is done to rebuilt heads to insurte a tight seal on the face of the seat. It's done by grinding the seat at three different, progressivly steeper angles then grinding the valve itself to match the seat. I understand that it is because the seats have taken a beating in the past and this technique helps to maintain shape during continued use and hence a good seal for as long as possible... sorry if this is redundant.

[TPIGUY]

Texas,

Its a lot more than that. A 3 angle valve job is for performance engines mostly. It helps the air flow around the valve smoother than without, but it really only makes a difference when the rest of your engine is built with high RPM in mind also. In short, its a waste of money on a low reving engine.

TPIGUY

[gsmikie]

a single degree is the longest lasting valve job for a everyday driver most single angle valve jobs out last the motor first the seals go then the timing chain then gaskets then vacum leaks and that is what burns the valves

[OBX-AUTOMOTIVE]

:cool: smile.gif