ddub

Im redoing some of the porting on my intake manifolds, and now I have a rotary "dremel" type tool with a bunch of accessories it came with. My question, for those of you that have done any type of porting with a dremel type tool, what accessory/bit did you use to do it? I've been trying some of them but they keep breaking. Am I doing it on too fast of a speed or am I just using the wrong ones? Any info or experience with this would be helpful, and I do not know any of the names of the sanding/cutting bits, so a description or picture would be helpful

My88Se

iTrader: (10)

I used a tungsten carbide bit that dremel makes. Worked really good at removing the material. Can't get that real smooth with it though, so I used some sanding drums to finish it off, starting out coarse and finishing with fine. the really coarse sand paper also works wonders at removing material fast. Took down the runners in no time.

ddub

Yah I'm trying to use the sanding drum, but it keeps slipping off the thing. Any suggestions on how to keep it on?

brainndropp

Superglue

WonkoTheSane

iTrader: (2)

I used a diamond tipped grinding set that I picked up locally for about 12 dollars, had 10 different shaped heads to sand things down, then I used the course sand paper bit, followed by the fine sand paper.. .worked great

drago86

Widget supply has carbide bits for the dremel up to 1/4th and inch. They work great for porting anything, including motors. The first time i did my manifold though i used stones,.. stones take forever though, get a carbide bit, they last forever if you use them on aluminum.

ddub

Yah I went and got that tungsten carbide that was suggested, and holy crap it works well. Its cutting through so fast, way way better. Thanks for all the suggestions and help, it's much appreciated

razorback

http://cgi.ebay.com/ebaymotors/ws/eB...483105056&rd=1

i bought these. have not recieved them yet but when i do i will let you know.

Icemark

Tighten the screw on the top of the drum. The tighter the screw, the more the drum expands to hold the sand paper roll.

pinkfloyd

razorback let me know how those work out, i was about to buy them.

razorback

i will. im still waiting to get them. im considering polishing up my ports. or a small street for the time being.

SureShot

Have a look at these:
http://cgi.ebay.com/ws/eBayISAPI.dll...823871204&rd=1

pinkfloyd

i was looking at those to. But why would someone need more then one. I mean they dont where down much at all. enless you are really grinding something away. thats how i look at it

fastrotaries

Hey read the directions that came with that thing. Just my $.02

ddub

Hey the thing was from ebay and came with no directions, thumbs up!

ddub

Thank you, since I have no directions this was helpful.

razorback

it should include 2 washers one for the bottom one for the top to hlep compress the rubber to expand and help the screw gain more area to do the compression.

ddub

Yah I figured that out now.

The tungsten carbide is doing great porting and 60 grit sand paper drums are smoothing it out really well.

ddub

That's sweet, I was wondering which type of bits would be best for porting a motor. Does anyone know if the ones included in that would be best? Like, for example, the one shown up close in the picture? Eventually I am going to be porting my motor myself, so I'm trying to figure out what type of bits to use.

pinkfloyd

i dont see why you would need 10 of them. just buy one localy.

ddub

True, but I'm still wondering which would work best for motor porting.

andrew lohaus

this is how i did mine and got great results. the tungsten bits cut very smooth and predictably. not to fast to get you in trouble, but cleaner and faster than using just sanding drums.

try dipping the bit in some 20w-50 every minute or so while you are porting (or just drip some on the part you are working on). this will cool and lubricate the bit to make smoother cuts and keep the shavvings from filling up in it's grooves.

finish it out with the 120 grit drums and voila- ported intakes!

Makenzie71

I use a router and a long, cone shaped aluminum oxide bit.works great...very smooth.

Falcoms

Hey, guys, you are not going for smooth when porting the intake ports on the engine, you want it rough to keep the F/A mix disturbed and mixed when it goes into the chamber. The exhaust, on the other hand, you want as smooth as can be so that there is as little back pressure to slow the rotor as possible.

andrew lohaus

this is realy only true of carb'd engines where the fuel/air mixture travels the entire intake track. on our cars there is only fuel in in the secondary runners of the lower manifold (below the secondary injectors). and while a mirror polish might be over kill and could possibly cuas a little fuel drop-out, you certainly dont want it rough. it should be atleast smooth to the touch.


and dont kid yourself that a rough surface keeps the fuel in the air. pop of your lower intake and look in the secondary runners. they are pretty rough from the casting and most likely slimmed with the varnish of accumated feul.