cork gaskets

[garrywlh]

Could someone please help me understand the correct use/benefit of the cork gaskets (or, joint washers, I believe they are also called?) that came in my engine rebuild gasket set?

I've read a bit and it seems that it depends on what material the cork is mixed with as to what use it is designed for?

Thanks,

Garry

[gromit]

Which gaskets were cork ?

The rocker box gasket is usually cork and can be assembled with just a smear of grease on each face. Highly compressable (takes up any imperfections between the two sealing surfaces). Can reduce transmitted vibrations, also reusable a few times.

Some info here Custom Gasket Manufacturing | Composition Cork and Cork Rubber Products from Custom Gasket Manufacturing

From the above site "good for low bolt load application" which would apply to the rocker box. Big area and just three nuts to hold it down.


Colin

[garrywlh]

yep, thanks gromit. I did use a cork gasket on the rocker cover, now that you mention it.

These for example, which came in the kit I got from British Off Road for Hedley's engine overhaul.

So I see now that they are a mixture of cork and rubber?

That big triangular one, for example...exhaust manifold to exhaust pipe?

[gromit]

Thermostat housing, again cork/rubber to deal with uneven surfaces and low hold down force.

Colin

[ezyrama]

yep, thanks gromit. I did use a cork gasket on the rocker cover, now that you mention it.

These for example, which came in the kit I got from British Off Road for Hedley's engine overhaul.

So I see now that they are a mixture of cork and rubber?

That big triangular one, for example...exhaust manifold to exhaust pipe?

Hi Garry
Is the Large triangular one oil filter housing to block or fuel pump to block on deisel and I think the small triangular is fuel bowl bracket to block .Is the rectangular one a side plate gasket?
Cheers Ian

[dandlandyman]

The big triangular one goes on the back end of the camshaft. The small triangular one is for the thermatic cold-start switch if fitted. The circular one is for the distributor, and the rectangular one is obviously for the flywheel timing cover where fitted. Thermostat gaskets are paper.

I usually use a far-superior cork gasket material on the rocker cover, sump and transfer case bottom plate as I find the type with a lot of silicone rubber in it squashes too much and can't be reused as it is too easy to break and sticks to the surfaces. The good stuff is expensive though.

I also never use gasket glue or grease on cork gaskets as it allows them to squish more.

Dan.

[mick88]

The "T" shaped one is for the bearing block on the rear main of the crankshaft housing!

Cheers, Mick.

[Ozdunc]

I usually use a far-superior cork gasket material on the rocker cover, sump and transfer case bottom plate as I find the type with a lot of silicone rubber in it squashes too much and can't be reused as it is too easy to break and sticks to the surfaces. The good stuff is expensive though.

Who does a cork sump gasket? I just ordered a Payen gasket set and even that has a paper gasket (although much thicker 1-1.5mm)

[gromit]

4 Wheel drives (Melbourne) sell sump gaskets and from memory they are cork.

Colin

[gromit]

I also never use gasket glue or grease on cork gaskets as it allows them to squish more.

Dan.

Never had a problem with using grease but then overtightening may cause a problem.
I've re-used rocker gaskets multiple times without issue and have used a dab of sealant to hold a cork gasket in place (F-head motor) also without problems.

Often the gasket will stick to the parts being sealed (hence the grease). Inevitably half way round it sticks to one part and the other half it stick to the mating part. A thin blunt knife run round to free the gasket helps.

I've only used gaskets from std sets but there would be better (read more expensive) materials available. I'm sure that 4 Wheel Drives in Melbourne get some of their gaskets from a local supplier so they have paid for the dies and then have a choice of material that can be used.


Colin