port and polish: dremel and AlO grinding ball?

[BerniniCaCO3]

Hi!

Doing nothing ambitious at all; I'm not going for enough performance to care, and while I'm sure I'd do just great porting and polishing from past carving endeavors, I've got too many other things going on in this engine build to spend too long on this.

But I was advised to at least knock the pointy casting line in the exhaust chamber down a little, so I figure I'll spend 30 minutes and do just that.

I know an air grinder with a proper 1/4" drive made-in-us tungsten carbide burr, with single cut fine teeth, would be the way to go; but I have a weller-made dremel type tool in my box handy right now and was wondering if it should do alright?

Well, I imagine it should. My real question: is there an important reason to go with a toothed carbide cutting bit, and not an aluminum oxide grinding bit? I'll be hot tanking once more after I'm done, so I'm thinking there shouldn't be abrasive dust about, if that's the reason.

[johnunit]

It will take

FOR-EV-ER.

Trust me, I'm working my way through doing minor portwork on my new intake with a dremel. You can't push that hard or it'll bog down. The bits don't last very long at all (in the minutes or few hours depending), and they aren't generally long enough to reach into the port (I would imagine even an exhaust port).

That's really the main reason. You will be there forever. To give you an idea, it takes me a good five minute to knock down very minor casting lines 2 inches into the manifold, per side, per runner. That's just to knock a VERY minor (16th of an inch at the most) casting line down, and not do a perfect job. To do any real removal of iron you'll need to use an air grinder or AT LEAST a proper carbide burr. I've basically given up until I get a burr going and set up my compressor because I consumed an entire evening without much real progress.

[mitymerc]

^what he said!

I tried w\a dremel & killed it. Air or proper industrial elec grinders are necessary.....

[DuceAnAHalf]

i gasket matched and knocked all the exhaust bumps out of cast iron heads with an air grinder and a carbide burr in about an hour. it will take you at least 4 hours to do ti with a dremel assuming you dont destroy it, youll also go through bits. How much is your time worth?

[Crownvicman289]

How much is your sanity worth?

Fixed.