One of the holes on the discharge part of my turbine is stripped to the point where the 8mm stud will go in and feel like it's threading, but it's not staying tight. So I immediately thought about a helicoil as probably being my best option (just wouldn't be able to remove the tang, but that shouldn't be a problem should it?). Or I was thinking of drilling the hole out to accomodate a 10mm stud, or maybe the 8mm->10mm stud 034Motorsports sells.
Any insight or advice? And if a helicoil is the best option, where is the best place to buy an 8mm kit? After some searching, I found a few kits on eBay, but that was it.

 

A drill and tap for 10mm studs would be cheaper than the drill and tap for the helicoil i bet. Then you could redo it all at once and have better hardware.

 

Well, for reference's sake, the heli kits are running around $15 and made by Perma-Coil.

 

10mm.. do it, forget it, while your at it do your manifold bolts for grade 10 too

 

And so yet begins another project. lol
OK, since ATP Turbo lists 10mm x 1.5 studs, I'm looking on McMaster-Carr's website, and I'm guessing that I need an M10x1.5mm tap, right-handed thread direction (durr), but what type of tap will do the job well? And what material?

 

Anyone?

 

It's just cast iron, you don't need a titanium tap or anything. Get what you can afford, if they're cheap enough get two incase on gets super dull while using it. The key thing is to use alot of oil/lubricant. Run it in a little, back it off, run it in more, back if off. That cleaning action will keep things working well for you.

 

any tap will work, just use the appropriate tap drill. for anything that is metric, the rule of thumb is the major diameter minus the thread pitch, so for an M10x1.5 you would use a 10-1.5 = 8.5mm drill. use some tapping oil when you tap the hole, but if you don't have any, just about any oil will help, even some wd40 is better than tapping it dry. usually, i don't back out while i'm tapping, i go right to the bottom, then out, but everyone does it a bit different... it also depends on the material being tapped, if it is a blind hole or not, etc.