Replacing cylinderhead

[Charles P]

 There is though, no matter what anyone else says, more of an issue sealing modern gaskets than there used to be with traditional copper asbestos gaskets. I don't wish to scare monger but simply warn owners to beware, I have lost count of the number of engines which have been brought to me for work and once the head has been removed there is evidence of water damage to the bores and valves and seats.

I share your cynicism about modern asbestos substitutes - they just aren't as good as the carcinogenic originals. I bought some original old stock gaskets (ex Kirby Wiske) from Tony Betts and look after them with care. When I recently had the engine apart I removed the block and head as one to avoid disturbing the joint face! When I've used my spare I'm back to modern ones.

However, I'm a fan of 5920 - another disciple of Mr Jones. 

C

[Ian Williams]

Thanks for your input Charles and another respected member trusting Loctite 5920 certainly strengthens its case. Paul I am very interested to know more about your gasket ideas, I have also experimented with solid copper but had somewhat mixed results.

[Rogerfrench]

Somewhere my father wrote an irreverent suggestion to use soft goat poo. Then if it blew, it would smell like a farmyard which is a relaxing smell.
I know of no actual implementation of this advice.

[JonE]

A few questions:
Are 5920-smeared gaskets just as re-useable as greased ones?
Or don't we know because generally they aren't taken apart, as they haven't failed!
How long does one have to get the gasket on and get it torqued down after the smearing process, bearing in mind one has two smearing processed to perform? I found it a bit difficult getting the stuff even as it's the same colour as the gasket. (But that consisted of moving it about with the finger until it had a recogniseable coverage... even thought it must have been slightly less than uniform)

[Ruairidh Dunford]

Jon,

I leave it to cure for at least 24 hours before use.

It can be carefully removed from the gasket, if the joint is dismantled.

[Ian Williams]

Interesting Ruairdh, up until quite recently you were an adamant grease only man, what has made you change your mind?

[Ruairidh Dunford]

Up until two years ago I only ever used Copperslip.

You highlighted numerous issues you were having with head gaskets seeping internally - and reported using spay on Hylomar to cure at that time.

I spoke to Terry Griffin who had mentioned using the copper silicone and asked him why? He told me that he had used it as a preventative measure for some time.

Steve Jones later told me that it had originally been developed for Fiat (I think that is correct) with the intention of it replacing copper type gaskets all together. This did not transpire but the product was made and can be used as described above.

I have used it on around 30 engines since then.

I have no personal experience of the gaskets weeping but your reports as to the failings of the new gaskets were vociferous enough to convince me that bad times were coming. I had no reason to doubt you, so use it in the spirit of a “belts and braces” approach - which sits happily with my general outlook on such things.

[Ian Williams]

Thank you Ruairidh, I asked because you were at one time very strongly on the Copperslip camp, something I have had past success with on engines with excellent mating faces. And yes two years ago I was using Hylomar spray, it seemed to be effective a lot of the time however I have not hat complete reliability particularly with higher compression ratios. What I am most curious about is that you quite obviously work on a lot more engines than I do, probably at least double by the numbers you mention in some of your posts, yet you say you have seen no evidence of seepage. I on the other hand would suggest something like half the engines that have been brought to me show some evidence of water damaging bores, and or causing corrosion to valve's and seats on one or more cylinders. Trying to understand why this may be the case and what is a reliable solution is the thrust of my discussion. One thing I have noticed which may have a bearing is the condition of many NZ blocks, corrosion seems to be more of an issue than I remember in the UK, it is not uncommon to go through into water jacket with just a +40 rebore. This I believe may be because with our warmer climate very few (particularly North island) cars have been used with antifreeze or any other corrosion inhibitor, water transfer passages between head and block are often in rather poor condition and may be a factor in why I have found more evidence than you have.

[Ruairidh Dunford]

Perhaps your net needs to be cast further than me?

[Ian Williams]

My net is cast as far as this forum reaches which I hope is across the world