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copper head gasket redux


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Apologies for dragging up an old subject yet again , but I have managed to source a couple of the discontinued 1147 Payen head gaskets , which I understand to be the gold standard, and was slightly surprised to find they are solid copper.

Given their apparent scarcity, I don't want to screw them up, and am confused by a lot of conflicting advice over whether or not to use a sealant.

Many opinions online: Wellseal, Hematite, copper sealant, grease, etc  or nothing at all, but I can't find a definitive answer.

Opinions and experiences welcomed?

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Are they solid copper or copper asbestos, more likely the latter?  By far the best to use on a flat deck block/head - I invested in a batch of a dozen for my big six engine when they were on offer from a reliable source at a special bulk buy price.

Either way do not use any sealant because it can be a right effing **** to clean off.  The only time I have used sealant has been where corrosion around the water passages have left the surface around the holes a bit iffy, and then I put only the slightest smear around the water passages over the corrosion itself.
Clean the mating surfaces of the block and head carefully then a smear of grease over each surface (not the sealant), put the gasket on the block, then carefully lower head onto it.


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Copper on both sides Ted, don’t think there’s anything between.  I’ve no experience of Payens, other than hearing of them constantly recommended as the best, and long out of production for the 1147, but understood them to be a black composite, so was surprised to find copper which I thought was just used for esoteric racing heads.

But these are very old CE421 sets, labelled as being for the Herald 1200 and Couriers, 61-65, though they seem to fit my head perfectly.
Water leakage was my problem, so your advice taken on board. Thanks

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Copper asbestos gaskets can often look like solid copper depending how they are made.

The bore hole is always rolled over and you can see the join on one face.  However the outer edge of the gasket could have been left cropped so the asbestos filler is showing, or the edge rolled over to seal in the 'asbestos'  If you file a tiny nick into the outer edge of the gasket (corner?) you will find that the copper is less that half a millimeter thick.  Mind you unless new old stock the filler is unlikely to be asbestos due to restrictions in its use, old compressed gaskets are comparatively safe due to the heavy compression of the asbestos layer though really to be legal they should be disposed of as asbestos waste but rarely are.

Another thing is that the copper asbestos gasket because of its sandwich construction needs to be put on a specific way so is marked 'top' or 'front' or similar, where the design is such that in can be put on either way.

The reason why I query the use of solid copper is the ability to compress satisfactorily such a large area of sheet copper.  

Back in the 1960s when my brother Phil (he with the saga of the TR4A ) used to be heavily into Morgan three wheelers - driving them as everyday transport, extended journey's with them on holiday and trips around the country to watch race meetings, and (primarily Phil) racing them, and we had this solid copper/copper asbestos option - with solid copper preferred.  
However we were using Matchless and JAP vee twin engines and the clamping force on a single cylinder gasket best described as about 4 inches rounded/square was considerable compared with a long four cylinder head gasket.  One of the advantages of the single cylinder solid copper gasket was that if heated the right way so that it ALL went cherry red, and immediately plunged into cold water to anneal it, enabled it to be re-used a number of times both with water and air-cooled engines.  You could even buy a piece of 1/16 (I think it was) copper sheet and cut out your own which I did on a number of occasions.


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You are quite right Ted, on looking at them again I can see white fibre showing between the layers within the stud holes, all others being rolled over.

They appear to be covered in some sort of clear lacquer which has kept them shiny and bright, bar just a few spots of light verdigris here and there. I assume I can lightly polish the green  off before fitting?

No Front or Top markings on them, just AE320, Made in England and 207930 stamped in.
Curiously, the packaging has been hand altered to change the number to 321, but the gaskets are stamped 320. Don’t know if this has any significance.

Would the rolled-over flanges be top or bottom would you say?



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That thin layer of lacquer keeping the copper clean and bright is also intended to act as a sealant when the gasket gets heated.

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That’s what I suspected Paul, so also slightly concerned that where there are these bits of corrosion breaking through the lacquer, the seal might be compromised even if polished out.  Which was leaning me towards applying a tad of wellseal..

Or am I overthinking this as usual?

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Right back from the garage after sorting out (constructing) a suitable case for the glass display cabinets that we used at the NEC.

From what my ancient brain remembers the stanped lettering was always to be positioned uppermost.  Also the folded over edges such as round the fire ring had to be downwards towards the block face.

The lacquered layer was as much for protection in storage as for anything else because it was always the norm to use grease which would affect the ability of laquer to act as a sealant.

That corrosion really should not be there if it was a copper asbestos gasket which will have had one edge rolled over where the bore is.  However I believe some did have a steel liner rather like 'modern' composite gaskets but this would show as being crimped both sides - if only crimped over one side has to be copper to match the face of the gasket.  Interesting that the crimped over stud hole has similar corrosions to the fire ring ........ and there is even a bit of corrosion on the copper face.  Is it possible to post a photo of the other side of the gasket at these points?

At worst I would scrape the corrosion only over gently with a sharp ('Stanley') blade and rub down the areas of corrosion using 240 - 400 grit wet and dry used dry and see what it looks like - can't do any harm as the gasket should not be used in this state anyway.  If corrosion rubs down smoothy i would put the mearest 'few thou' smear of gasket sealant over the corroded area (let it dry a bit) and then use grease, or simply use only smear of grease.
The beauty of this type of gasket is that it will compress down more than a composite one which starts off thinner and has less compression in it, though probably ending up the same approximate thickness as a composite one ...... about 40 thou.

However you must ask yourself whether:
1. You want to use the gasket and risk failure.  Shouldn't cause any actual damage if it does fail but could happen at an inconvenient moment
2. Not worth the hassle of risking a faiiure and not use it.


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Hi Ted. Appreciating your input here.
Other face is clear and clean as you see. Corrosion is definitely light verdegis from the copper and not rust, is quite greenish.
Hardly surprising for a 50 year old part I suppose.

A light rub over with 0000 wire wool has cleared most of it, and Im fairly confident(!) there is enough compressible “meat” to seal, I hope.  Ive oiled it for now.

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Interesting to read Ted recalling our Morgan 3 wheeler racing days - for a 1931 1100cc car the Moggie could fly, 2 forward speeds only(no reverse) and 90mph when geared up for the back straight at Silverstone, and on the "A" and "B" roads beating many road cars in the 60s and 70s.
Relevant to you and confirming what has already been said, I remember back then the adage that "Grease won't pass water and Water won't pass grease" and it's why we always used a light smear of grease on 4 and 6 cylinder head gaskets particularly.


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