Heli coil or tap and die

[bcjjones]

Previous owner stripped out a couple bolts holding the exhaust manifold on the head. I'm about to install an evo mani I just bought. Would it be smarter/easier to just heli coil the stripped bolts or the tap and die new threads?

Obviously I would have to go one size larger on those bolts which is for one scary drilling into an aluminum head and also not sure if it would mess with a coolant route through the head or anything. Seems like much more of a pita to tap and die because I believe I would have to also drill the holes in the evo mani to fit the larger bolts. I'm thinking just heli coil it but wanted to ask yall would yall would do?

 

[jpmxrider489]

Tap is to put threads in something and die is for the outside. There studs not bolts. So i guess if there stripped out i would just heli coil it ao you can use studs.

 

[99gst_racer]

HeliCoil. A helicoiled hole will actually be stonger too.

 

[bcjjones]

Alrighy so have yall ever used just the little heli coils availabe at the autoparts store?

 

[jpmxrider489]

Youll want something that could get hot. Im pretty sure you dont want to use cheap bolts from lowes in your turbo. Same said with anything else. Take pride in your work. I know some people are on a time crunch but I hate to see people cheap out and then pay again for the same part just better. Sorry for the ramble. I believe I heard on turbo tech on here people using heli coils for the turbo mani bolts.

 

[99gst_racer]

Alrighy so have yall ever used just the little heli coils availabe at the autoparts store?

Yup. Every hole on my head is helicoiled.

 

[TofastForU_99]

Alrighy so have yall ever used just the little heli coils availabe at the autoparts store?

Yes they work great, or you can get a timesert insert.

 

[romeen]

Agreed, do the HeliCoil. Assuming you're still using your 1G head, you need an M8 x 1.25 kit. Mine required me to buy the drill bit separately, which was a 21/64" but other kits might be different. If you're doing this with the head on the car then a right angled drill can make things easier as far as the limited space between the head and radiator.

 

[jpmxrider489]

Yup. Every hole on my head is helicoiled.

You know the bolts arent holding up the empire state building. You dont have to crank them down. Just torque to spec.

 

[Tommy's]

i would helicoil. I recently had to retag out the holes for my valve cover to bolt to head. It wasn't a pain in the @$$ but helical seemed to be the better option and it definitely seems like your better option since u are bolting the mani up. and like JPM said don't do it cheap. get the right bolts/tools.

 

[romeen]

You know the bolts arent holding up the empire state building. You dont have to crank them down. Just torque to spec.

I'm not saying it should be done, but I can understand why some might want to do this. In my experience, they can strip well before the recommended torque spec. I've had one strip at 14lb/ft even though the 1G torque value is 18-22. I know this because I was adjusting the torque wrench in 2lb/ft increments starting at 10 due to precisely this issue in the past.

 

[99gst_racer]

You know the bolts arent holding up the empire state building. You dont have to crank them down. Just torque to spec.

I've had 4 or 5 holes strip over the years. I eventually just helicoled them all. Mine supports a bit more weight than most, and I can't reach them with a torque wrench either. So, it's nice being able to tighten the piss out of them to know they're definitely tight enough, and not worry about pulling the threads out of the head anymore.