Yes the genuine bolts are plated 10.9 grade high tensile steel. you can see what the Porsche bolts look like in the pics below, they have 10.9 stamped on the top

I have never used stainless on exhausts due to lots of stories of it causing more problems than it solves. A lot of it may just be internet legend though.

I've found the dry moly paste to be better than copper grease type stuff.

The copper stuff eventually disapears and after a couple of years the bolt is just as hard to remove as one fitted dry.

The dry moly will still be there and the bolt will be easy to remove, thats been my experience anyway, unfortunately its expensive.

By the way I've had good results with the freeze type penetrant sprays as mentioned above, they do seem to work better than the traditional sprays, I would spray the snapped studs for a good couple of hours before you attempt to remove them, you want do everything you can to make it easier.

Tim your right it is a ZX7 H2 in the back ground, well spotted. It was known as ZXR750 over here though, have you got one?

 

Hey Frank

You're lucky if your heads were 10.5mm
Mine are down to less than 8mm and are pretty much perfectly round, the Irwin bolt removers can't grip anything on them

I haven't attempted trying to remove the sheared bolts yet
My plan is to remove the last remaining bolt and take the manifold off first
That way I can get some penetrating oil onto their threads before going to work on them

I've got the drivers side manifold off and I've run a die over the turbine studs, so that side's ready to go back together once I get the new nuts and bolts

I'm thinking whilst I'm doing this I should probably remove the exhaust and replace the nuts that hold the cats to the turbos - they're in the same condition too

I was so angry when I sheared those bolts I had to walk away from the car

Whenever I have a problem with it I tend to leave it for a while, then give it a wash and a polish!!

I find if the car's looking nice I soon calm down and gain my composure again

The car's looking really good now, so I'll have another crack at it again tomorrow

 

I like your philosophy,I will try that with mine when it goes wrong.lol

 

Works every time

You can't get mad at a car that's just been cleaned

 

Righty-Ho

My nuts and bolts arrived today
I ordered stainless steel items

I know they don't have the same tensile rating as mild steel
But the header doesn't require very much support, it's just not that heavy

The one thing I'm not sure about is whether the stainless bolts would be more prone to shearing?
Common sense says the material is more likely to shear, but then, as it's stainless, it should be less likely to become seized to begin with
Hmmmmmm

All being well, the plan is to refit the right hand side header tomorrow and then get working on the left side header and studs over the weekend

Stay tuned, as I'm sure there are more mishaps ahead!

 

Nice one Ant. Good progress so far
I didn't use Stainless as it has a tendency to Gaul, that's as bad a corrosion. However that's normally Stainless on stainless. So perhaps just SS bolts would be fine?
How did you get the sheared bolts out?? Have you yet?? Its that , that was my biggest worry.
Good luck.

 

Thanks Frank

I haven't got the sheared ones out yet, I think that'll be my weekend job

As I can't undo the final bolt holding the left manifold in place my intentions are......

Grind the bolt head off
This will hopefully allow me to remove the manifold (I say hopefully, as the turbine studs and sheared studs in the head may stop it being removed)
With the manifold removed I'll soak the sheared bolts with penetrating oil
After soaking I'll then try and remove the bolts
If there's a lot of thread protruding from the head I may be able to get two nuts on it and try and remove it that way
If not I'll try and get some grips on them to turn them
If that doesn't work I'll try a stud extractor on them

I'm still trying to work out the best approach for the stud extractor though
If I have to go down that road, I can't decide whether to refit the manifold (to act as a guide for my drilling) or to grind the bolt flush with the head and then use the extractor

I guess I'll have to remove the manifold first to see just how much thread is sticking out, I think that'll make my mind up for me

 

Hi Ant

Another method i've used in the past if you have some stud left sticking out, is to place a larger sized nut over the remains of the stud and mig weld it to the stud. This gives you a good big nut to turn.

On the last one I did like this I used a whole can of freeze spray. The stud started moving but would only move a tiny bit then went tight again.
I was patient and made sure I didn't turn it too hard, I kept at it with the spray and slowly got it to move more and more and eventually got it out without damaging the thread in the Head, I would try this method before you try the stud extractor method if at all possible.

I think the heat from welding the nut on also helps to loosen the stud

The worst that can happen is it snaps off again and your back where you started

I'm not usually lucky enough to have some stud sticking out though.

I think I still have the last stud I got out in the garage somewhere I'll see if I can find it and post a pic.

And

 

Here's the pic

Good look with what ever you do

And

 

Cool
I've got a 180 Cebora mig, so I'll try that before the extractor

My new phone arrived today, so I'll take some pictures for everyone too

 

I've just managed to grind the head of the last bolt, but still can't get the manifold off

I can put a pry bar anywhere along the manifold and it'll move - except for this last bolt (which is now headless)

I would have thought with a little perseverance I would be able to wiggle the manifold off

But now it seems the bolt is stuck to the manifold


Has anybody got any suggestions on how to free this bolt and the exhaust manifold?
Should I keep going with the penetrating spray?

Once I've got the manifold off I can start working on removing the sheared bolts

 

You could try prying with a bit more force, the manifold may pop free. If you've removed all of the bolt head there is no reason for it to be stuck other than its trapped by the studs

If you feel like you've already put as much force as your comfortable with then I think it would be a good idea to remove the exhaust as everything else connected to the turbo has some flexibility (oil lines, boost hoses, upper support bracket). With the exhaust off the turbo should be able to move enough to to get the manifold off.

Removing the exhaust can cause its own problems though

The four cat nuts might be difficult to remove. I've seen posts where some are easy and some are a nightmare. Access to the top ones is not great, and you don't want to snap one of the studs off. I would use the "grind flat and chisel" method here as its a lot less likely to result in a broken stud

Access to the top nuts can be greatly improved by removing the bumper, rear heatshield, rear arch liners and intercoolers and bending side heatshields up. This may seem excessive but experience has taught me that anything you can do to make things easier when working on corroded parts is worth doing. Imagine how you'd feel if you snapped some of the studs in the turbo

The exhaust at the rear is held on with two band clamps and the allen bolts will most likely be siezed.If you can't get them from below access is much better if you remove the rear bumper and heat shield. If you can't get them out you can cut the bolt in the middle to release them.

Hope it goes well and you don't find yourself walking away and doing some more polishing, at the rate you going you'll be down to the primer

And

 

Ok, I've got some good news
I've managed to beat the manifold off the car!

The bad news is I can now see what I have to work with

 

Anybody got any ideas what's caused those bolts to corrode to that extent?

Some of the filth you can see is the penetrating spray, but what would account for the rest of it, and why are these studs so bad compared to the others?

Id like to resolve this before refitting the manifolds

Also, now ive got some pictures for you has anybody got any suggestions regarding the removal of those sheared bolts - or should I just go about it as previously discussed?

 

One of your bolts was fractured a long time ago while installed. Try cleaning the threads well with a chaser and use some never seize. I shouldn't have to say to torque and re torque to the manufacturer's recommended numbers.