stripped exhaust stud repair

[jimbo74]

i was told by several members here that helicoils are worthless... and going the next size is impossible without major modifications

the issue is stripped exhaust studs on the rear of the exhaust header.....

duffil told me to locate a part called st-39. which i did, also got the tap for it... it is 7/16 - 14 on one side and 3/8 - 24 on the other side. i was told since the holes are already stripped that is basically like they are drilled out, and by using the 7/16 - 14 tap, i could get the stud in and with the 3/8 - 24 side would still fit through the exhaust manifold.

now the issue i am running into, is the stud has a little area between the 2 sides that is larger than the larger side of the stud. do i need to grind this down in order for the manifold to sit flush? or just thread it in there in the tapped hole and let it spread the itself into the head to accommodate it?

[RustyToy]

seams to me that the fat piece would fit into the really stripped part of the head so it would be flush with the head.   

[jimbo74]

 

[Willy Mammoth]

I would grind it down being carfull not to under cut it or damage the threads.

I would have just used a helicoil or a time sert, but this should work too. Just remmember the threads are differant from all the rest.

[mudmaster]

i was told by several members here that helicoils are worthless...

I've always had good luck with Helicoils 

[Duffil]

drill
tap
install
bolt on manifold
done

[jimbo74]

drill
tap
install
bolt on manifold
done

i thought you said i wouldnt have to drill it out, because the hole is smooth due to the fact the studs pulled out

[Duffil]

i dont remember much...if it's already that blown out, try running a tap down it.

[meanokie]

all you have to do is drill
tap
install
bolt on manifold
thats all all i did on mine

[Duffil]

all you have to do is drill
tap
install
bolt on manifold
thats all all i did on mine

yeah, but you don't know up from down. 

[jimbo74]

it is already blown out... its actually missing the 2 rearmost studs, and there are no threads left in either of those holes.....

[Duffil]

1. grow a sack
2. fill it with some nuts
3. tap that biatch!
4. bolt 'er up!


easy, right?!

[Talon84x4]

I tried already, it didn't work  .

I've got one furthest forward stripped out and need a fix as well, all threads gone also.

[mudmaster]

When you helicoil a hole you are actually oversizing the hole then tapping it for the actual insert which will be the size you started when you are done. Any of this make sense?

[79coyotefrg]

When you helicoil a hole you are actually oversizing the hole then tapping it for the actual insert which will be the size you started when you are done. Any of this make sense?

to  us YES,  to them,  apparently NOT

[Duffil]

When you helicoil a hole you are actually oversizing the hole then tapping it for the actual insert which will be the size you started when you are done. Any of this make sense?

to  us YES,  to them,  apparently NOT

It makes sense, Glen, I've just never had any luck Heli-Coiling exhaust stud holes.  I've used red loctite, sleeve retainer, they have always come out.  Studs, however, I have not had any issues with.  Of course, the engine that had those issues was cobbled together from about 10 different trucks, so I dunno.

[jimbo74]

When you helicoil a hole you are actually oversizing the hole then tapping it for the actual insert which will be the size you started when you are done. Any of this make sense?

no, it isnt that i dont know how to use helicoils, i am not using helicoils.

ok here is what i am going to do. im going to start tapping it, if i notice it doesnt fit and i need to drill it out, i will, if it fits im running it all the way in there