I've got one of the holes drilled
Just got two more to go, then it's on to the head!!


Hole enlarged to 10mm


Manifold with drill bush fitted (10mm OD & 5.5mm ID)

 

Thanks Nick & Frank
I've been using Titanium and Diamond drills
I'd not heard of Cobalt ones - I'll order some now

 

Max - Here are some pictures of the nuts holding the turbine housing to the cats

 

Sorry to say but if this is your drilling technique then I'd suggest that you ask the help of a professional.

 

Thanks Stef,
I think I'll get some help when I start work on the head itself

I broke that drill bit on the manifold

I'd drilled one of the holes out in order to fit the bush, but the drill bit got stuck after id got through it

The drill I was using didn't have a reverse gear, so I had to forcefully remove the bit from the manifold

 

My hats off to you for even attempting this. I've never seen corrosion or rust that bad, but I live in the 1st or 2nd driest state in the US. Sometimes we don't see rain for months.

 

Haahaa, Thanks
But I still haven't done much yet

The right hand side exhaust manifold was removed and refitted without issue, but the left hand side has given me some grief

Whilst everything possible has gone wrong there's still no major or irreversible damage
So far the worst thing I could do is ruin my manifold........so what

Now, once I get on to drilling the head I might require some assistance , but I'll cross that bridge when I come to it


As you can see from one of my previous posts all the exhaust fixtures are shot
I still haven't decided whether to remove the entire system and replace all the fixings, or whether I should leave it well alone until it leaks

Based on how much trouble this (small) job has given me I might leave the rest of the system until it 'needs' to be done


I can tell you one thing - I'm not in any hurry to swap my turbos!

 

Ant
That is bad, mine are about the same. The nuts on my Turbo
just crumble when you touch them. I am taking some brave pills
and will start removing my Exhaust bolts this weekend. good luck

Max

 

Those flanges look like they're type of stainless steel.

Stainless is very hard and there is a saying for drilling hard materials which is "high feed,low speed"

This means the best way to do it is to use a very slow speed ( 1 rev per second is fine) while pressing very hard,idealy using a pedestal drill.The swarf should come off in two continuous strands. If it starts to squeal your going too fast. Cutting oil also helps, if the oil starts to smoke its getting too hot,stop and let it cool down.

The drills in your pics have been far too hot, this destroys the hardness of the drill. It can also make what your drilling go even harder due to the heat.

The studs are also a hard material so these tips apply to them too.

Hope this helps

And

 

Max - Some of the bolt heads on mine were crumbling like you mentioned, but the majority of them are just corroded down to round 'blobs'

Given your location I can imagine your exhaust fixings have seen some pretty bad weather too - I'd go very slowly if I were you

One thing I will say (despite having three sheared bolts in the head) is at least the bolts I'm having trouble with are the ones that are easier to get to

 

Thanks And

My buddy also told me I've been drilling far too fast
It sounds like slow and steady will be the winner this time around

At least I'm only messing with the manifolds at the moment, so there's nothing too scary going on

And yes, the flanges are stainless, and are a bastard
I think even once I've got my technique down they'll still be hard work to drill out

 

Thought you might like to see what a car that has lived in a dry climate looks like from the underside. Generally a joy to work on.

 

Update

I've started drilling the head today
Everything is going well, I've had no problems so far

BUT, drilling is going very slowly
I'm working on the first stud right now, and i'm about 10mm into it

I've got three studs to do in total, and need to drill them to a depth of 30mm

Is there anything I can do to speed things up, or is it best to go slow and steady?

(It's taken me about 3hours to get 10mm into the first stud)

 

I'm almost through the first stud now
Once I'm at the required depth I'll enlarge the opening and then retap it to M8

I've had a look at the second stud (cuz my arms are tired and I need a break)
The stud isn't centred with the hole in the manifold, meaning if I use my drill bush I'll be drilling slightly out compared to where the original hole was

I've loosened the bolts holding the manifold in place, but there's no play, so I can't get it centred at all

My options seem to be
1) Drill it as it is, the hole will be slightly out from where the original hole was, and will mean I'm drilling into the head casting

2) Enlarge the hole in the manifold in order to centre the hole again
But then how would I ensure I was drilling into the head at a straight angle?

 

Here's a pic.....

Not sure if you can make it out from the photo, but the stud is all the way over to one side

If I drill the hole central to the manifold it will mean drilling into the head casting by 1-2mm