Thank you Engine Guy

Like Nick has said, I think it would be possible to find somebody to weld my head, but how do I find somebody that's really up to scratch?

I don't know of any good garages or machinists, hence my trying to fix this myself


I'll give you guys an example:

I spoke to the Porsche garage that serviced my car last time around to see what they would advise

They told me it was a waste of time taking the cylinder head off as you can't get 'inside' the water jacket anyway

I made it clear that I'd drilled straight through the head into the jacket and that the hole was no longer blind, but he was absolutely adamant that you cannot get to the back side of the manifold bolt hole

If you see the picture I posted earlier of a head being machined you can clearly see you have access to the inside of the water jacket

Since they're telling me things like that I haven't got any faith in them to do a good job - I think they're guessing at things about as much as I was


What do you think would be the best way to find a good shop?
Should I look for a car garage, a bike shop, or a general fabricators?

Thanks again
All help is appreciated

 

It might be worth giving Hartech a call as they could certainly do the job without any problem.

 

Thanks mate
I've not heard of them before

Just Googled them - Are they in Bolton?

 

Address:
Hartech Ltd
Firwood Industrial Estate,
Off Thicketford Road,
Bolton,
BL2 3TR

http://www.hartech.org/

Probably the most experienced Porsche engine rebuilders in the UK - worth giving Baz Hartech a phone call.

 

One thing to keep in mind is newer shops, say in the last 20 years or so, do not hire craftsmen. They hire parts replacers. You need to find a guy that knows how things work and how a good solid permanent repair can be done. You probably won't find this in a modern garage as today's mechanics, actually they're called techs now I believe, are taught how to diagnose a problem, unbolt and bolt on a new part.

Look for a small automotive or motorcycle shop that's been around for a very long time. Tell them what you did and how you would like it repaired. Maybe they have their own ideas as well. Someone that's been in business for years has seen it all and knows his way around tools and how to work with metal. Visit places like this and if they can't do it ask if they know who can.

Porsche or any modern shop would most likely want to see you a new head. There is not a lot of money to be made in doing the type of repair you need. GL!

 

Nick thats very good advice

Hartech is such a place , they have proper machining facilities, I recommended them back in post 131 , I thought Ant would have known who they are as they are very well known and respected in the UK. Baz who owns it is an engineer with a lifetime of experience

The main problem you will have is getting them to do the work as they are a very busy shop, and are inundated with 996 n/a engine rebuilds.

And

 

If you can get them to do the work then Hartech would be the best possible place for you - they are a centre of excellence in the area of bespoke engine rebuilds etc

 

Lots of advice on how to repair already in this thread, here is how I would do it, or would suggest to the shop doing the work

I would use a 1/4 NPT plug to make an insert. It's just the right size to drill and tap an 8 mm thread. I reckon you would have a thread depth of about 10mm for the 8mm bolt which would be enough to get full strength, and because the bottom of the plug is still solid it would seal the coolant perfectly.

I use 1/4 NPT taper plugs at work just with a bit of PTFE tape on pressures of 230 bar and it seals perfectly so the 1 bar in your cooling system will be no problem. I would not use PTFE but a thread lock that also acts as a sealant.

I would also practice on a piece of scrap alluminium first so you know it will work ok on the head itself.

looking at the attached high quality drawing should give a better idea of what I'm talking about.

Notes

Drill the plug with the correct size drill for an 8 mm thread. I would drill it on a lathe to improve the chance of keeping it central

Cut the hexagon head of the 1/4 plug

I would cut a shallow slot in the top if the insert so you can screw it in with a big screwdriver, it doesn't need to be that tight.

The depth the thread is cut with the tap is critical due to the fact the thread is tapered. You would need to do it by trial and error,tap a bit then try the plug then tap a bit more and repeat until the depth is correct.

I have some 1/4 plugs somewhere I will try and find them and put up a pic

And

 

Ant,
"KIS"
Drill out hole, put in re-coil insert to the full depth of the hole. Screw a 5 mm thick plug down the hole untill at the bottom of re-coil insert. Seal with thread lock or even 2k adhesive ( just like the water pipes are don by Porsche.
Measure the remaining depth and cut your M8 Bolt to suite.

If due to all the drilling off centre you have done, the bolt is misaligned with the exhaust manifold, then file slot the hole in the exhaust manifold. It will fit and all it does is hold on the manifold along with a load of other bolts.

This has gone on far enough mate. Its going to cost you megga shortly.
Bit like the old kids song "The little old lady who swallowed a fly"
KIS is the key. Its only a hole in the water jacket. Its not under all that much pressure.
Call me if you want or PM me. this is an non critical repair, keep the cure that way as well.
Frank
PS...........
Just to show how simple this is and high light its not a real great issue if you wanted to and were keeping the car, just put a re-coil insert in. smother your M8 bolt in 2k adhesive tread lock and tighten up the M8.The worst thing that will happen is the next time you remove the bolt it will leak coolant. When do you next expect to remove the exhaust manifold and if you do how hard is it to do the same thing. The next step of putting a plug at the bottom of the insert isn't all that hard and will effect a good repair.

normally a Tap depth 1 1/2 times a bolt diameter is required for max strength, but if you get 10mm its not overly load bearing and would probably suffice for an exhaust manifold.

 

I've just managed to get the corroded nuts off - grind and spilt was a great suggestion - many thanks
Any reason why I shouldn't fit stainless (a2 -70 grade m8s) as these are turbo specific locking nuts rather that the standard steel ones ?
Cheers ade

 

Stainless nuts can be used, but you should use lock washers with them. I prefer the serrated "star" type lock washer, not the split ring style.

Or buy flanged SS nuts with a serrated bottom. Those would work perfect.

I only say locking methods as stainless nuts will tend to work their way loose over time when in used in high heat/vibration environments without some for of lock(Ie tab, wire, washer, etc)

Ant holy hell this has been a mess for you. Wish you were closer to me and I would have just taken care of this myself. Best of luck. Other have posted viable methods of repair. Personally I would weld it but the plug options are viable as long as it's done properly.

 

Hi all,

A bit of a thread resurrection but rather than start a new one I thought it best to add to this one.

I would be grateful if you could help me. I have read through many of the posts on this thread and was hoping for some recommendations.

Here are my objectives. I am looking to change:
- The stock exhaust for a Cargraphic
- Change the Turbo Heat shields
- Change accessible bolts/nuts to new bolts/nuts whilst the exhaust and bumper are off.

Firtsly, are these the fixings I should look to change/will need:

Exhaust Cat to Turbo:
8x M8x28mm bolts (are these flat head bolts, studs or actually part of the turbo unit ?)
8x M8 washers
8x M8 locking nuts
2x New gasket rings for Cat to Turbo

Turbo to Manifold
3x M8 nuts
Anything else eg washers, bolts/studs etc ??

Turbo Heat Shields
2x new Turbo Heat Shields from Porsche

Is there anything I would be missing to achieve my objectives stated earlier?

Finally, what is the consensus on here eg stainless steel bolts/washers/nuts, stainless steel bolts/washers but with copper nuts, Porsche stock etc ?

Thanks for your help.

 

i know that this is a thread revival from the dead but i just wanted to thank you for this tip... i was dropping the exhaust and found myself in this exact situation... no amount of penetrating fluid or heat helped to even budge the nuts... i used your method and they came off with a few taps of a hammer... i didn't have a chisel small enough so i just used the biggest flat head screwdriver and sharpened the tip...