Evo3 housing bolts re threded

[Sachsline]

I purchased this evo3 turbo from a member here and i was getting ready to put in on my car and come to find out some one had the holes on the housing drilled bigger 12mm with a 1.75 pitch.What can i do? Machine shop said helicoil wouldnt work as it would be too thin to work with.

 

[Vegas Smith]

You could drill out the holes on your exhaust manifold to fit the 12mm bolts. It wouldn't be that hard.

 

[boostdawd]

Use some smaller diameter bolts and secure them with lock washer and nut from the bottom. That way u won't have to worry about bolts seizing if u use the current size.

 

[Sachsline]

Using a nut at the bottom wont work as there is no flat surface for it to seat on. If i drill out the mani to 12mm who carries a oem strength bolt?

 

[JDT]

Every used E3 housing I've seen has had this problem. Some people just weld a nut on there. I just threw mine out and bought a knockoff housing and ported it.

 

[donniekak]

I used m8 bolts and nuts on every one I had. I used to repair the threads but it's a losing battle. A washer will turn itself into a locking tab type washer on the bottom of the housing. Just use a fairly thin washer.

The best part is when the nuts seize to the bolt you can just break it with a breaker bar, remove both ends and not battle a broken bolt in the housing ever again.

 

[boostdawd]

Even though the housing is not flat trust me it will seal. The washers will help with it.