Silicone - is this one any good for what I need?

I have a tube of NO NONSENSE General Purpose Silicone Sealant, clear.

I'm told it'll be fine to go between the rocker box cover gasket and cylinder head, but the tube actually says "Do not use on surfaces that bleed oils or plasticisers".

Also, is it heat-proof?

I suspect I'm being paranoid again, but being clueless I have to ask!

This is the stuff ya want mate;

V-TECH COPPER RTV SILICONE GASKET MAKER RESISTS OIL 85g | eBay

Have used it before to great effect

Why are you putting sealant between the gasket and cylinder head? The whole purpose of the gasket is to form a seal between the cylinder head and rocker cover, and it is designed to do this without using any type of sealant. Using sealant may prevent the gasket from working effectively, causing leaks rather than preventing them.

If it cheap quality it wont last and will just create a mess or separate. Rtv silicon alright but don't use house silicon.
At Ford we use a silicon that is in a little hand tube and it alone costs over 40pound but it will seal almost anything.
If your new rocker cover gasket is rubber i would only suggest applying to areas where there are complicated shapes that are prone for leaking ie around cam housing and half moons if you have them on your motor

I was going to use a smear of sealant because the person I was talking to suggested I should... I know nothing though, and will do whatever I should do based on advice!

I agree that a rubber gasket should do the job on its own... but the rubber gasket on my motorcycle rocker cover does almost nothing! lol

Anyway... based on the advice here, I think I will not bother with any sealant (at least to begin with) and see if it leaks.

The gasket is not new, but it's in near-perfect condition and to be honest, there's no pressure build-up in the rocker box, so oil isn't going to be forced out through the seal... it might just seep out over time.

...and even if it does, it's not important... i'll just have to keep topping the oil up.

I will fit it with no sealant and see how it goes (unless someone now tells me not to...)

ordinary silicone will be fine you could pay £20 for a tube of some very posh stuff or use nothing but ive found it does help ,i use it all the time to seal the rocker covers

Hylomar blue,

Chrisfrain2007 said:

Hylomar blue,

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unless your Dad has a half-used tube of red lurking at the bottom of the toolbox.

Why not just get a new gasket for the sake of a few pennies?

you cant use non setting sealer with rubber gaskets or core plugs,new gasket is still better fitted with a little silicone,it holds it into place

right... as I was on a steam rally site with no shops nearby, I have fitted it without any sealant. Just the gasket (which was in pretty good condition anyway).

I'll see how it goes!

It's gotta leak less now anyway because the cyclone breather is actually attached to the engine at last!

james - i will send back my old rocker cover & cyclone breather soon if you'd like them...

yes thank you

jamesmartin said:

yes thank you

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wanna PM me your address?

Thanks again, James! Your help is really appreciated!