Dremel Bits

ClayGlover · Jul 27, 2004

Looking for info and recommendations on dremel grinding bits for port modifications and case flow work.

What do you engine guys prefer to use for cutting and smoothing? What types of bits and what shapes work well? I've used the diamond bits and the ones that look like sandstone in the past with decent results.

Thanks a bunch

Bart Drieghe · Jul 27, 2004

Stop using the Dremel bits , if you wanna cut things/drill/case flow /etc .etc , go to a shop for dental technicians ( not the same as Dentists !!! ) they got several drills for hard materials , metals etc etc . Yeah , they do cost more but live atleast 4 times longer then what you have from dremel .

Diamonds are very good , just make sure u're not making them too warm , they'll break off otherwise

Cutting discs , use the reinforced ones , never broken one ( except the one i stood on )

and oh yea , how do i know ?

i'm a dental technician

Bart

Rules · Jul 27, 2004

Hi Clay,

The diamonds that Bart is talking about are the dental ones, not the Harbor Freight, 20 points for $9.95. The dental ones like I have been using for 20 years are real tiny and just perfect for ultra detailed port work. Layout your work with Dykem and digital calipers. If the liner is used, then the oil stain is a perfect cutting guide. I start with a diamond point (not a cylinder) that is .045 dia and .375 long which easily breaks thru the chrome on the port flares. Then use fissure cut bits for general work that are around the same size. Other shapes are used for exacting countours. Pistons are real hard alloy, so diamonds work best and fissure for final smoothing on the window ports. Keep holding your flex shaft at oblique angles to prevent pitting on the flares. The final finishing work is done with a magnifying visor and a close light. If you don't have a flex shaft, get the Dremel thin black steel one, the small collet, and use a foot speed control. I have 7 flex shafts setup with different points that have been zeroed in for perfect tracking. The Dremel collets will be off center if they are used very much. The Diamonds/bits can be had from many places, but most easily from your dentist or his distributor. If you cant wrangle any, I'll bet Bart will send you some real good used ones, if not then I will get you a set.

Have fun and practice on an old piston/sleeve!

John in Huntsville

Bart Drieghe · Jul 28, 2004

If you cant wrangle any, I'll bet Bart will send you some real good used ones, if not then I will get you a set.

Well not that i'm not willing to help but im off to the World Championship in Slovenia( today ) so it won't be within the next 3 weeks . After that i'm again available .

Still , im sure that if u got a dental shop u'd find your choice(s) overthere .

Best Regards ,

Bart

Bart Drieghe · Jul 28, 2004

I shouldn't be helping you guys so much

B) B) but here are a few links , on the first link u'll see a few (dental )companies in the USA in the list , second is a company for jewelry but they use the same drills and burs . Just one thing ,

U might find that some prices vary a lot when it comes to diamonds :

Reason is :

the most cheapest ones : not centered , not sintered , only a thin layer of diamond :

middle class : centered , most of the time not sintered , layer is thicker

most expensive class : centered , sintered , full diamond

centered : well , that explains itself doesn't it , more out of balance , bearings of your dremel won't last long and u can't cut nicely

sintered( i might be spelling the word wrong ) : way the diamond has been made

difference between thin layer and full diamond , a thin layer will brake off ( or peal off ) It will heat up when u've been using it for a while and it can't stand the heat and simply brakes off .

Hope this explains a bit ,

Bart

http://www.dentnetkorea.com/overseas/pburts.htm

http://www.fdjtool.com/tools.html