Dkt26 said:
Dkt26 said:
Yes very cool combo martyn
I have stock compression with the comp gasket and am interested in the 21thou copper gasket. I don't want to have to do anything else like milling pistons etcetera.
Will I be fine to just assemble with the thin 21thou copper gasket from JS?
I would imagine my comp would come up a bit to say 8.5:1 or thereabouts.
Also with fitment , I've never done this before with copper gaskets. Done heaps of cars and trucks but never annealed a gasket before.
If I am going to be right just fitting the 21thou gasket with no other mods required, how do I correctly anneal the copper gasket? My limited understanding is that I just heat it with a handheld gas torch until it changes color then fit. Is this correct? Also do I need to do bolt up while the gasket is hot? Do I use any goo like hylomar?
It is cost prohibitive for me to get a full Jim head job as funny as that sounds to me!!!
Will the 21thou gasket bolt up with no other mods?
How do I anneal the gasket?
Do I use hylomar blue with copper gasket?
These are the questions
I'm not after bragging rights or horse shit stories from the pub
Just thought I would seek the info here
And no, it won't be the fastest commando to have ever lived!!!
Don't panic DK, the thread is titled 'full auto heads' and so far at least, that's what folk are talking about!
I looked into doing what you mention and I'm pretty certain that you can go to a .021" head gasket without having to machine anything. It is easy to check with everything assembled though. If its currently assembled, check now, then calculate what it will be like with .020" taken out of the equation. There is quite a lot of clearance in the stock set up though. IMHO this is because the factory intended a higher tune, then de-tuned at the last minute.
My guess is that this would get you back close to the 8.5:1 CR that it is supposed to be. So it's more blue printing than tuning really!
You anneal a copper gasket by heating it, as evenly as you can, to a cherry red colour using a blowtorch or similar. Some say you should let it cool, some say you should quench it. In my experience, both work. But the advantage to quenching is it helps to clean the gasket. The gasket should be cleaned with wire wool or similar afterwards.
Copper gaskets tend to leak a little oil around the oil drain hole and pushrod holes though it seems. Carefully looping some very thin soft copper wire around the holes, or thread, and keeping it in place with gasket sealer, seems to be the way to deal with this (see JS websirpte). It then gets crushed flat when torqued up. It sounds like a bit of hassle... But not as much hassle as removing the head to cure leaks I guess!
Some say copper gaskets should be greased, or smeared in sealant, etc. I have used a lot on Triumphs and always favoured fitting them as dry and clean as possible, cleaning all surfaces, and the gasket, with thinners or similar prior to assembly. I found copper gaskets to be very effective on all my Triumphs, Weslakes, etc.
On my commando, I have kept with the composite gasket though, mainly due to the oil hole and pushrod hole issue mentioned above and not wanting the hassle!
In summary, you should be fine. It seems that copper gaskets are highly likely to give you mild oil leaks. But they seldom fail catastrophically. Composite however, should be far more oil tight, but if they do fail, they fail catastrophically!
