ss1

iTrader: (32)

The supercharger mounting bracket for my Vortech mounts to the front of the drivers side cylinder head with four M10x1.5 bolts. I've been going through the car with a fine tooth comb and thought I'd put a torque wrench on the bolts to make sure they were tight. The two lower bolts, closest to the deck felt "soft" so I stopped and pulled them out. They were about 10-12mm shorter than they should have been and pulled the threads. There are still good threads in the bottom ~15mm. I'm going to get the correct length bolts today and try to torque it. Btw, I did not install the bracket or wrong bolts to begin with.

If the remaining threads don't hold, is there enough material around these two lower accessory bolt holes to install a Time-Sert or Heli-Coil? I'm borrowing a Time-Sert kit today to have on hand if I need it. I don't want to get too close to a water passage, port, combustion chamber, head bolt, etc. I figure at least a few of you must have experienced this in the past.

stevieturbo

Pretty sure helicoil requires a smaller drill hole.

And a Helicoil repair will be fart stronger than the original alloy thread anyway. Just heliocoil it.

Shownomercy

iTrader: (1)

Helicoil for that thread would be around a 10.5mm drill bit size, be careful with the drill point depth and maybe try a bottoming tap when threading it.

Blown06

iTrader: (32)

Yea a helicoil should work. As said you might engineer some type of stop on the bit though so you don't poke a hole.

stevieturbo

Most helicoil repair inserts are only about 1.5x the diameter of the bolt anyway.

So the hole really doesnt need to be drilled deep at all. Just measure and be careful.

You might even be able just to force the repair tap in without any drilling. Use cutting lubricant of some sort when tapping.

Although drilling first would be best. Just go gently.

flyingbrick88

Helicoils are not 1.5x original size. You may be thinking of keyserts (which I prefer)

The hole size for an m10 helicoil tap is 10.3mm so fark all wall is removed. Obviously the helicoil tap removes a bit extra.

No need to engineer a stop just mark depth of the hole on the drill with a pen. You only need to drill deep enough for the tapping and helicoil insert..

Be careful that you DO tap the thread deep enough before you wind in the helicoil as otherwise the bolt won't go in far enough and it will be a bitch to pull back out

stevieturbo

I didnt say hole size. Depth/length of the repair thread.

They come in 1D, 1.5D, 2D etc.

1D would probably be sufficient, although 1.5D would be better.