Then go for a 5.5mm drill guide and a long 5.5mm drill. A M8 tap has a 6.7mm hole so drilling with 5.5mm should be fine to start with.

Make sure that you grind the remaining part of the bolt nicely flat. The flange is 12mm thick and the bushing is 10mm long so the broken bolt might stick out just a little bit.

 

Stef, You're awesome!

Just ordered a headed bush - 5.5mm x 10mm x 10mm

I'll get my drill once the bush arrives

More updates to follow

 

Update - Or not?!
It's been a week and i'm still waiting for my drill bush to arrive!!!

I paid £4.34 for the bush
They charged me £6.00 postage!!!

And then charged me tax on the postage too
So I've paid £7.20 postage on a £4.34 part, which still hasn't arrived after a week!

NOT HAPPY

 

Finally!



Roll on the weekend

 

Ant,
I hope this works. I have my fingers and toes crossed for you.
Good luck

 

This is a ****ing waste of time!!!!!!!!

 

I've run a grinder over the studs do they're flush with the head

Next job is to enlarge the holes in the manifold in order to press the bush in place
The only problem with that is the ****ing manifold is harder than the drill bits are!!

So far I've ruined three drill bits
I've rounded two of them, and snapped the third one

God alone knows what Porsche made these manifolds out of







Anybody know how to remove a snapped HSS drill bit from a manifold flange?!?

 

Ant, in the end you might just have to drill the ***** out , start with small drill and work up. If you end up drilling out the threads in the head so what. You wont take all that much metal away. That's what inserts are for. I use Re-coil, similar to Helicoils. I have a stock of most sizes. In the end its just a head no more or less important or sophisticated as any other car. If your not 100% in line with the hole in the manifold, then use a Hardened Steel Bur and make the hole a little larger.
Re-coil inserts done properly will last forever. Go on the tinternet and have a look at them. The kits come with the required drill and taps and a number of inserts.
http://www.recoilshop.net/?gclid=CM_...FQUNfAodTnQnMw

 

Hi Ant
I am just about to do the same as you, my Actuator rod has broke, all the turbo nuts
are corroded away to practically nothing, the oil pipe connections look fubared too. I
am particularly worried about removing the Exhaust bolts as they are rusted as well, looking at possible problems to come that drill guide looks promising.It will be interesting to hear how you get on removing the bolts, I have been told by someone to heat up the bolts before removing and also to give them a sharp knock with a hammer first, I will of course be getting in touch with Frank to ask his advice about my getting my Turbo!s repaired anyway good luck with the rest of the dismantle

Max

 

Thanks mate

I haven't actually got that far yet though!!
What I've been trying to do is drill the manifold itself

The bush that Stef recommended is a push fit inside the manifold holes
The bush is 10mm OD, whereas the manifold holes are ~9.5mm, meaning they need enlarging slightly in order to press the bush home

The problem with that is the manifold is ludicrously tough, as you can tell from my drill bits!

I'm confident about drilling the studs in the head (when I eventually get to that part) as they seem to be made out of cheese!
But before I can do that I need to tackled this manifold

I'm thinking I'll take the manifold to a shop tomorrow to get the holes drilled

In the meantime, I'm going to refit the rightside manifold, as that one's ready to go
That way I'll feel like ive at least made some progress

 

Max, I'll take some pictures of the rest of my exhaust nuts for you

They're a ****ing joke

I can't believe how much must have been spent on the manifolds (seriously, you can't drill through them they're that tough) but then they go any use the ****tiest cheapest fixings possible

 

Ant

Sorry I posted before your latest debacle, I feel for you mate looks like the manifolds are the only tough bit on the car it really is a rust fest under mine take heed of Frank he has been through all this a more

Max

 

You may need cobalt bits that are stronger to get thru the manifold. And then need a drill press to get thru it. Here, correct speed and lube/coolant is important. I hope you're right about the studs being soft. Generally they are a grade 8 equal in hardness and the drill bits will just roll off. If they are hard as well, you'll need to start with a colbalt number 60 or so, very small and work upwards. In this case the bushing will need a reducer pressed in to center successive smaller bits. The problems are just starting, I've been there many times, do this stuff for a living and have since the '70s. I would have exhausting all attempts and efforts welding before attempting drilling. Sorry if it's too late, but I did mention this earlier. At any rate, GL!

 

Thanks Nick

I tried the welding route but had no joy

I'll be fitting a 5.5mm bush in the manifold flange and will drill a small hole into the studs in the head

The plan is to then retap the thread in the head with an M8

I think with the smaller sized bush being used first, and only being used as a pilot hole it shouldn't be too bad

Having said that, everything has gone wrong so far, so I'll probably have problems there too!

 

Ant,
Nick's right you must use cobalt drills. "Assumption is the mother of all **** up's" and I assumed you were using Cobalt drills. you must spend the little extra and get a set from 1mm to 5mm. I haven't used those steel drill inserts, I just took the bull by the horns and drilled slowly and accurately. I didn't even have to use Recoils, however I knew they were there just in case. ( this wasnt on the head btw, I was lucky i got mine all out......but only just and was very very lucky.)