This is so I can start the porting of the intake side of the head. I was wondering what "shape" would be the best for that work:

1/2" Tree:
<img src="http://www.harborfreight.com/cpi/photos//38600-38699/38686-t.gif">

1/2" CYLINDRICAL, RADIUS END
<img src="http://www.harborfreight.com/cpi/photos//38600-38699/38687-t.gif">

1/2" CYLINDRICAL, NO END
<img src="http://www.harborfreight.com/cpi/photos//38600-38699/38688-t.gif">

3/8" TAPER-14 ANGLE
<img src="http://www.harborfreight.com/cpi/photos//38600-38699/38691-t.gif">

3/8" OVAL
<img src="http://www.harborfreight.com/cpi/photos/38600-38699/38689.gif">

These are from HF's website. I'd like to buy a set but can't afford it right now. I'm also going to buy the set of 10 burrs for $20 from HF. I'm going to buy some flappers over the next week or so, too. Thanks.

But for the aluminum IM and/or head you'll want an aluma-cut bur. It has LOTS fewer teeth (much coarser appearing) and doesn't load up with material as fast. The best choice would be the 1/2" cylindrical radius-end if you only have one.

steel/cast iron bur will load up and ruin the bur. Always use aluma-cut burs (single helix flutes) on alloys and cross-cut pattern burs on steel/cast iron.

<img src="http://www.lightworksmediagroup.com/images/petes/bigBurr.jpg" />

<img src="http://www.lightworksmediagroup.com/images/petes/imarockstarburr.jpg" />

Does your sound grind? ;-)

for everything. Just imagine a one-style-suits-all-bur. The grinding world would grovel at your feet.

I'm incredibly interested in how you did a complete upper/lower IM port/polish with a ball bur and without benefit of a cylindrical bur which is used in way over 99% of all bur work required to port/polish an intake manifold.

I'm well into my second IM and I have less than 5 minutes total time with a ball bur and well over 20 hours with a cylindrical burr on two manifolds.

I want to know how you gasket-matched with a ball? How you did parallel wall-blending with a ball? Flat surface smoothing with a ball? Throttle body flange-matching with a ball? Only use I've found for the ball bur is at the base of 90 degree intersections which take about 2 minutes per IM on the primary inlets only.

Trust me, this isn't sarcasm. It's purely an overwhelming interest in technique that I'd dearly love to learn.

when I <b>did</b> use the ball burrs (3 sizes), I just kept it lubed and it worked really well. It does work incredibly fast though. And, IIRC, it was quieter than any of the others. That might be my imagination.

Also, of noteable concern, I'm VERY new at this, so I would take nearly everything I say about anything with a grain of salt. I am young and inexperienced. Hopefully someday, I'll be humble, too. Come to think of it, I'm the most humble person I've EVAR met. j/k