Jeff20B

I gave up on those metal bits a long time ago. I almost exclusively used cutting disks. I did use a couple stones here and there though. I also use the sanding drums to create a nice bevel. 2mm @ 45º.

andynogo

Yeah, what Tyson said.



I use an air powered die-grinder with much larger bits. Mine is 8-10 mm diameter. Goes through the housing like a hot knife thru butter. Takes less than 10 mins per exhaust port, including sanding/finishing. I use a dremel with the flexi for the final sand finish, but the die grinder I just attack it from both sides without any probs. Practice, practice, practice! Have fun

jspecracer7

hahaha you newbie!

phinsup

#1 sentance you don't want to hear the guy working on your motor say.....

mazdaspeed7

Dremels suck for porting. I use a 1/4" die grinder with carbide bits for rough porting, and an 1/8" pencil die grinder for the detail work. 70K rpm, it doesnt overheat, and its small and easy to control.

Fluid Dynamics

I love using a dremel and won't waste any time trying to use a die grinder the next time I port anything. The dremel allows better control and precision and the die grinder I had was very clumsy.

rx7_re

Agreed, the dremel gives me all the control I want. No real need to rush it, and besides I wouldn't want to.



Sanding drums are awesome, its also a lot easier to stay even throughout the port.

mazdaspeed7

With enough practice, nothing is clumsy or too fast. Ive got some new bits I need to try on the rotor housings. Those take WAY too long when you start doing exhaust ports like this.

j200pruf

I am porting a f-ed up throttle body and it is a bit harder than I thought, but I am starting to get the hang of it.

rx7_re

If your just taking away massive amounts of metal then I guess a die grinder would do the job. But in no way would I ever use it for any sorts of detail work, one mistake and you got yourself a big gouge.