Lancia Motor Club

Model Technical and Interest => Lambda => Topic started by: davidwheeler on 20 July, 2007, 07:01:40 PM

Title: Head gaskets
Post by: davidwheeler on 20 July, 2007, 07:01:40 PM
After much trial and error I have found a supplier of excellent copper asbestos head gaskets.  John Vessey has the details.

Title: Re: Head gaskets
Post by: Sebastien on 23 July, 2007, 07:56:05 PM
I am having new gaskets made out of modern material. I shall also report on them. I think that it could be useful to have only copper around the bores, and not in contact with the cooling water. i am always amazed on the amount of aluminium powder, or silt, certainly a result of bimetallic corrosion, possibly originating at the head/block joint, that circulates in the water passages, and stagnates around the cylinders were there is no water flow. Although the water circuit was flushed, and cleaned out, it has cost me a radiator, which had to be recored twice. Not a nice experience, for the nerves and the bank account!

Title: Re: Head gaskets
Post by: davidwheeler on 01 August, 2007, 04:38:40 PM
I also tried modern material with copper liners round the bores but the stuff was too thin and did not compress enough so I got a bit discourages.  I know the Aussies use modern stuff and it works so I guess we need a spec. from them?

Title: Re: Head gaskets
Post by: johnturner on 03 August, 2007, 09:17:54 PM
The most effective gaskets I have used were made by Klinger using 'Klingerite' with steel welts round the bores, in effect the kind of 'modern' gasket you would find in any parts shop, but the tooling for the steel welts has long since disappeared. Quite apart from the advantage in limiting corrosion, these worked by applying serious pressure onto the liners, where it matters.  If you have to use a copper asbestos gasket it is good idea to tuck an extra copper shim about 5mm wide under the welt round each bore to acheive something of the same effect.

Title: Re: Head gaskets
Post by: Sebastien on 06 August, 2007, 03:56:24 PM
My experience with head gaskets up to now has been that sealing problems were due to the top face of the block being warped. The problem is that to surface the block you have to take off the head studs, which can be a difficult job if they are stuck.

I shall from now on if required always first check the surface of the block with a straight edge, before putting the head on again.

Now the car is running fine, with a modern composite gasket, with welts around the bores.

Title: Re: Head gaskets
Post by: johnturner on 06 August, 2007, 08:57:09 PM
Corrosion and sticking of the studs is a problem but it has been common practice in the UK to use Helicoil inserts which deal with damaged threads and allow relatively easy extraction. I assume that similar inserts are generally available everywhere under different trade names.  It is true that no gasket will seal unless the block is absolutely flat.  The problem here is usually caused by overenthusiastic tightening of the holding down nuts which, beyond a certain point, do not so much bring down the head as bring lumps of the block up to meet it.  I have never seen any factory advice on the appropriate torque but Bob West reckoned to pull a head down at 65 ft/lbs and leave it at that.

Title: Re: Head gaskets
Post by: davidwheeler on 13 August, 2007, 02:05:57 PM
I even have some Helicoils and tools from 30 years ago but i'll hang on to them I think as I don't know if the VIIth has been done.  I'm happy to lend the tools though.
John, I think my gasket chap can do steel welts as we discussed them before I decided on copper.  I think if I were to use thicker gasket material it would work but copper asbestos was quicker and easier at the time.  I find extra copper round the bores is only necessary when reusing a gasket and bought a sheet for that purpose.  How thick was your Klingerite?

Title: Re: Head gaskets
Post by: johnturner on 30 August, 2007, 04:12:36 PM

Sorry to be slow to get back to this.  A new Klinger gasket still sitting on the shelf is 2.3mm thick, or about 3/32 in old money.