Head bolt leak.

[Steve Berg]

I'm particularly interested in this thread since, after rebuilding my Nippy engine and fitting a new 9E1 cylinder head (Tony Betts) with a 9E1 gasket (Ian Williams via Martin Baker) I'm experiencing head bolt leak on a newly assembled engine for the first time in the 50 years I have owned the Nippy. There is also a slight leak at the front-left corner of the gasket. 
The remarks about the changed gasket materials are interesting. The core of the 9E1 gasket seems considerably harder and thicker than the previous asbestos ones. The copper surfaces are also thicker, and stiffer, than the last standard HC gasket that was fitted - roughly 0.3mm compared to 0.1mm.
So I was wondering whether it would be advisable to apply more torque than 20 ft/lbs to the cylinder head nuts so as to compress the gasket more. What do you guys think about that? I don't want to break the studs!
The gasket was sealed with grease which, as Ian also mentioned, served well previously. However I have now ordered some Loctite 5990 from Simply Bearings - just in case.

[JonE]

I have also bought anti seize grease - copperslip to do this job, after reading a recommendation elsewhere. Can we clarify - is ANYONE recommending the anti seize copperslip grease for this purpose?! I will now buy some Loctite 5990 but I suggest people stop using the ambiguous C- word if not...

[AustinWood]

My thoughts on head gaskets:
If the surfaces of head and block are sound and flat and the stud and nut threads in good condition there should never be any problem with head gasket sealing. The nuts should run smoothly on the studs by hand.
A smear of grease lubricates the gasket and allows it to settle correctly as it is tightened. It has no sealing effect.
Soft gaskets lead to problems. They tend to compress around the studs causing the head to bow and in time also the block to rise up so that there is a high spot around the studs. This has the effect of reducing the compressive force in the areas between the studs.
Tightening the head further tends to increase these effects and make it worse.
On my engines, when reassembling, I ensure the block face is flat by removing the studs and rubbing the mating surface on two sheets of emery cloth glued to a flat piece of kitchen worktop - home made surface plate. The high spots around the stud holes show up straight away and it can be surprising how bad they can be. Treatment continues until an even colour across the face. Same treatment to the head.
When fitting the head I tighten it down progressively in the correct sequence and use a ring spanner of normal length done up firmly by hand. I don't use socket spanners here. After a few miles I retighten by hand with the engine cold.
I've never had any head gasket problems over many thousands of A7 miles. I reuse head gaskets, lightly greased, many times provided there is no mechanical damage.
A firm gasket on flat surfaces gives best results. This is the reason modern engines use metal shim gaskets and stretch bolts.
The shim gasket ensures that it is an even thickness all over. Stretch bolts, at the point they start to stretch permanently enter a stage when the force applied remains constant as they are further tightened. Hence the 2-part tightening. First they are torqued down to the start of the stretch phase, then a further rotation takes them into constant force. This gives consistent and even tightness to all the bolts.

[Hedd_Jones]

given my daughters RP has a habit of leaking oil into the coolant (but not the other way around), and as a result of repairing a leak on the water manifold the head gasket is now weeping at the front, I think I shall give this Loctite stuff a go with a new gasket

[JonE]

for some reason, it seems super cheap at Halfords...

[Hedd_Jones]

Jon

Id sooner trust the recommendation of the individuals here rather than dismiss it because of how cheap it is at Halfrauds

[Graham Honnor]

Hello All

I've been cautious not to tempt fate and reveal my results but as the original poster I thought I'd better do so now as the post has been brought back to life again.
Well, as I said at the time, I used the anti-sieze copperslip on the gasket and it certainly sealed apart from the stud bubbling so I continued to re check the torques every outing for the next few times until I couldn't get any more movement on the nut at 18 lbs. 
This didn't stop the bubbling around the centre stud so I resorted to removing the nut and applying some jet-blue (a plumbers best friend) around the thread and retightened the nut.
Since then, no bubbling and a perfectly good head gasket seal so, so far, so good.
I still may try the 5990 if I do have any more issues but hopefully not for a while.
Once again, many thanks to you all for your support.

Graham.

[JonE]

Jon - Id sooner trust the recommendation of the individuals here rather than dismiss it because of how cheap it is at Halfrauds

it was intended to be a positive signposting to it...!

[jansens]

Hello All

I've been cautious not to tempt fate and reveal my results but as the original poster I thought I'd better do so now as the post has been brought back to life again.
Well, as I said at the time, I used the anti-sieze copperslip on the gasket and it certainly sealed apart from the stud bubbling so I continued to re check the torques every outing for the next few times until I couldn't get any more movement on the nut at 18 lbs. 
This didn't stop the bubbling around the centre stud so I resorted to removing the nut and applying some jet-blue (a plumbers best friend) around the thread and retightened the nut.
Since then, no bubbling and a perfectly good head gasket seal so, so far, so good.
I still may try the 5990 if I do have any more issues but hopefully not for a while.
Once again, many thanks to you all for your support.

Graham.

Just a thought but if you seal the leak at the threads at the top would that mean there is still water between the length of the stud and the head? Could that cause issues later on such as having them rust together? I might be misunderstanding and the head is on mine now so I can't go look at it to see how it works. 

When I did mine I used sprayable blue Hylomar on the gasket on the recommendation of my engine building place. They even offered that I could bring in the gasket and they could spray some on it for me to then fit it at home but I managed to buy some locally online, it's not available off the shelf easily I found.

Engine not running yet so no idea how well it will work. I suspect it will seal well but it seemed so sticky I am not sure what getting the head off at a later date will be like!

Simon

[Graham Honnor]

Hello Simon

You are quite correct, I believe, in that the stud may have water around it but the alternative would have been removing the head once again and I wasn't really in the mood to do that.
I would probably have had to disturb the stud and that also didn't fill me with enthusiasm so I decided to go the route that I did and face any consequences later on if necessary. 
However, I did coat the stud with copperslip as I mentioned earlier, so that may help a little...who knows.
I will report back if and when the time comes, and possibly ask for more help then!
So, for the time being I seem to have a sealed head and I wish you lots of luck with yours.

Graham.