Anyone have any recommended tools to make smoothing the inside of a set of TPI runners easy / fast / dead simple?

-I'm thinking something like a flexible hone brush-looking thing that you can just attach to a drill and run through the runner for a couple of minutes and smooth out the casting bumps in the interior.



Please don't hijack the thread with your random, unsolicited opinions on why it's unnecessary or why you haven't done it. Just looking for ideas on HOW to do it easily and inexpensively (abrasive silly putty for $1,000 is out).


Adam

 

The factory runners are smooth inside and are not cast they are tubing. Some aftermarket ones are cast. Which ones do you have?

 

FIRST Fuel Injection Runners. 1.75" inside diameter.

My first thought was to use a Flex Hone of 1 7/8" diameter -say 60 grit so it will smooth pretty quickly and still end up fairly smooth if done around 1,000 RPM. You could also control taper of the tube based upon how fast you make the hone continue down the tube.
BUT... I called BrushResearch who makes the flex hone and they don't think it's flexible enough for this application. ;-(


Adam

 

Not to mention, they would prob clog up with aluminum really fast.

 

I used a flex hone on my stock ones after I expanded them, it will work, just make sure you get the hone for aluminum and not steel or like the last guy said it will clog quick. The bristles will start to misshape by the end but it was plenty to finish my set and when they misshape they just get smaller over time. Hit the runners halfway from one side then the other. 60 grit is pretty coarse.