Help required damaged head at exhaust port

[daysofthunder]

Hey guys can this be fixed? Sheared exhaust m8 bolts . Put m6 drill down it then tried easy out and this happens
I was thinking about drilling straight through and putting a nut on the other side but though there might be a water jacket there ?
Any help much appreciated
[URL=http://i24.photobucket.com/albums/c33/d ... s7g6uv.jpg

[itchyfeet]

If you can wait until tomorrow I can drill through an old duff head to see if it hits a waterway, I don't think it will but they are close.
Can't really get a nut on the back but probably enough material to tap deep assuming it does not break through to the coolant.

[dumbo]

or if you get stuck what about chemical epoxy??? just a thought

[daysofthunder]

Hi thanks for the replies , that would be great if you could test a scrap head to see it breaks any water jackets

I think I may be able to tap deeper then liquid metal as a final measure

I have drilled the other snapped off bolts with an 6mm drill . Following a 6.8mm drill and tap 8mm 1.25 see how well it taps . Failing that 8.8mm drill for a 10mm 1.25 bolt

It's a job I wish I had not started , but worth it when im camping with a cold beer in hand

[itchyfeet]

I will do another slice that side to be sure and get pics up, the other side is max 25mm deep as can be seen here...

[kevtherev]

Round here you can get that welded up and re drilled and tapped.
Aluminium welding is not uncommon.

[itchyfeet]

No you can't drill through, 25mm max depth

[daysofthunder]

Thanks itchy feet

So far I have repaired all 3 and re tapped to 8mm

I have some thinking to do about the next step on the 4th hole

I am not sure how reliable the liquid metal would be so maybe welding might be the answer

[itchyfeet]

You may need to fit the exhaust with one bolt to drive it to somebody who will weld it in the van, don't really want to take head off and unlikely to get an ally welder to come to you.

[daysofthunder]

There is a good 10mm thread there and the bolt feels positive in the tapped hole
Think I will leave bolt in and liquid metal around the exposed area leaving to cure then wind out the bolt
Slightly on the pi$$ but offered up old manifold and there seems to be enough play to work with

Ps ignore length of bolts correct ones will be fitted

[what2do]

Looking at your pics above, you've nothing to lose by going ahead with your plan, it's certainly the easiest and less expensive! I wouldn't use that bolt for tightening too much, it may just rip out. The other bolt ought to keep the mating faces together sufficiently for it to not leak. Suck it and see.

[what2do]

Do you need to coat the bolt with a grease or similar to prevent the liquid metal adhering to the threads?

[kevtherev]

I should point out that a VW exhaust hangs on the head mountings, any weakness here and the vibration will cause leaks.
without a proper repair it must be only temporary until you can have it welded