Porting Burs for Aluminum in Dremel


What do you guys use? The ones that come with the dremel are for steel and plug up easy. Aluminum ones typically have less flutes.


Dawg 89
Driver ordered some off fleabay. 3-4 inchs long , that worked good .
I've heard wax or parafain helps .


I did a little work with WD-40 and it works ok but makes a big mess. Would like the right tool for the job, if one exists.


Site Supporter
LPC3 (or some sort of lubricant to keep the aluminum from sticking to the cutter) goes a long way.
I would think that you would want something a bit more "robust" than a Dremel for porting.
I use an air die grinder (porting tool) that has a 1/4" collet and accepts a wide variety of cutting, sanding, & polishing bits.
Actually, I have several (to speed up the porting process for business purposes.)
I really like to use the cylinder spiral flute ball end cutters for the bulk of porting. A reverse cone for working the inside radius and other undercuts, sanding rolls (tapered and straight) for minor material removing, and flap wheels or similar for polishing.
You can pick up a pretty decent starter kit of sanding rolls and polishing pads used for porting from Goodson Shop Supplies. That would be a great place to start. Tell Dave "Hi" for me and that I sent ya. ;)
If you plan on doing a lot of porting, spend the money for a good die grinder (ie NOT Harbor Freight quality.) Personally, I'd rather purchase a good quality used tool from an aircraft maintenance surplus (or similar) than some of the new stuff on the market today.
Most of my personal die grinding equipment came from surplus aircraft tool actions and surplus tool shops. Some are 30+ years old and still used in the shop if not every day, nearly every day.

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Carlson Racing Engines
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I port 1 head a year. Dremel seemed to work fine for that, and with the snake attachment could get up into the ports farther.

Example of this you use? cylinder spiral flute ball end cutters

alvin l nunley

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What do you guys use? The ones that come with the dremel are for steel and plug up easy. Aluminum ones typically have less flutes.
Here's a picture from Victornet.com for a grinding tool, which turns all a lot slower than a Dremiel tool. I've seen this one in action and I've coveted it ever since. A Dremil tool will do the job, but like you say, the tools load up.
port grinder.jpg

Bob Evans

Every Dremel I've had, the speed was variable.

As an aside here, Smokey Yunick maintained that the backsides made hardly any difference, that he smoothed with the direction of the air flow and just left the backside in most cases. 'Course Smokey was known to spin a tale or two.