SKeown wrote:I'm on the verge of collecting two burrs for port matching an aluminum manifold. I realize the ones specific for cutting aluminum are needed, along with a short & long shank. What I need advice on is the best shape, there are many to choose from such as round nose conical, round nose tree, egg shaped and so on. I know to be properly setup to do such work full time a person should have a complete variety, but I'm just doing one manifold.
SE-5L6 in Alumacut for roughing and larger radius
SE-3L6 in Single cut for finishing and smaller radiushttp://www.carbideselect.com/se.php
FWIW- for what your doing, buy a common air die grinder for $35 and be done, gets the job done just fine. Learn some speed control and patience waiting for the AC to keep up.
I went to a GDO-601 about a year ago- should have done it sooner. The SE-5L6 may want to start with a wobble (in the GDO), just lay the shank lightly on a pc of wood as you start it and it gets past that rpm where it wants to vibrate. I use it at full bore, cuts thru CI like nothing
I only use the air grinder now for sand rolls at low speed and some chamber work.