Has anyone used those dent remove ***** to expand their Stock runners? Guys on ebay are saying that one of the ***** is extra large and will expand the inside of the runner giving you 9% more flow. Wonder if anyone had experience that proves then right or wrong.

 

9% increased flow? That's a pretty bold claim.

Stock runners average 1.540" I.D., or about 1.8617 in² of cross section. To increase the cross secional area by 9% would require swaging the tubes up to 1.607" I.D., or about 0.067" total. That's going to take some ball(s) to push through. I think there would be some trouble even getting them through the cast flanges.

 

I bought a set and don't believe what you hear.
They are a little smaller than inside and will not take out all the dent. They do help a lot, but you still have to get out the old bondo and smooth.
They will now go all the way through either. Almost all the way. Enough to get the cowpile size dents though.
Ron

 

I had a TPI runner that came on a engine that was damaged when the PO pulled the motor. Pretty nasty looking. I bought a set of those *****, and heated the area around the dent a little with a propane torch. (Not enough to bother the finish on the Corvette runner.) It did not take all the dent out. So I took a small hammer, and worked the area with the ***** in place behind the dent. It did a real nice job of getting the dent out. I was impressed with how good the runner looked.

Know that larger ball that comes with the set? No way that was going to get into the runner unless some alterations were made to the flanges.

Scot

 

Ebay has become snake oil central in the last couple of years...probably why the kids end up with crap parts on their crap cars,, they believed what they read on Ebay..

 

Also note, a 9% increase in flow does not mean it has to have 9% more area. Area and flow are not the same thing. BUT, if you force a larger ball through the runner it will try to straighten it out some and you will end up with junk......

 

I saw these and was wondering just for removing dent wise. Ive got one nasty one, and 2 small ones in a set of runners.

Trying to decide if trying to find another set of runners, or get these *****.

 

Correct. However, I strongly suspect that someone reselling gage ***** as "TPI Dent Removal Tools" likely hasn't invested in a flow bench to check the results of swaging up the runners with maybe a .005" larger ball. You can buy the same ***** at McMaster for a few bucks each, even cheaper at your local industrial supply house (McMaster is never a bargain).

And if you've ever blueprinted a set of TPI runners, bases, and plenums (pleni?) you'd discover that there is more than 0.020" of variation between runners in the same set, even on the same side (one assembly). That's why I mentioned a nominal size, since it changes from tube to tube.

Furthermore, comparing several different sets of TPI runners, bases, and plenums (pleni?) side-by-side, you'd see that the variability of manufacturing can just about completely eclipse any gains made in such a process. I'd suspect a greater gain can be achieved by simply port matching all the connections.

 

I tried to get a set of these ***** cheap and couldn't do it, a member on these boards sells them btw. I finally decided to fix the dents myself and used a 3/4in closed end wrench, stuck it into the runners until it butted up to the dent and tapped it with a hammer. I completely removed my dents on all 8 runners this way, it took a bit of patience but the outcome was awesome. The only other thing I wish I could've done that I can't with the hammer and wrench setup was take out the dimples they made to clear the stock torx head bolts. I use regular 6 point bolts now and would like those gone.

 

I haven't used the dent removal ***** but shoving a ball through the runners isn't going to increase the flange size. There's your limiting factor. As far as improving airflow by 9%... I suppose it depends on the size of your dents! If they look like crumpled up beer cans you may see an improvement... but I doubt it.

 

you also have to remember that stock runners dont flow very much to begin with... so a 9% over stock isnt that great of a improvement.