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Matthew in TO
Matthew in TO
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Hi there,
Ready to install the head on my B31.
I know there isn't a head gasket used but is there a sealer that should be applied?
Thank you,
Dean

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No, no sealer. But might be a good idea to lap it a little. Some valve grinding paste and then a little work similar to lapping valves. Just a few minutes, makes it look nice. You can also use some to lap the magdyno pinion on to it's shaft.

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Thank you, did lap it in. Hope to get it together tomorrow.

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I don't know for sure that a sealer would be ill-advised. Just not needed. Might take a while to get another opinion here.

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Ok, right. Over on the brit car forum have read numerous references to a product called Copper Coat gasket compound.

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Copper coat is for coating the bottom of boats to stop the barnacles growing, it's not a gasket compound.

Copaslip is a high copper content grease for anti seize, not a gasket compound either but it has been found when coated on copper head gaskets will help the gasket seal better. As does silver spray paint and a few other similar items coated on gaskets.

https://www.molyslip.co.uk/copaslip/

So not applicable to a gasketless joint, stick with what Leon suggests, a good clean flat surface on both components.

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kommando: Over here we have 2 or 3 brands of spray-on gasket sealers commonly called "coppercoat". For head gaskets, etc. I use it, but only on some hard gaskets.

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Hi Dean,
The correct method of preparation is to lap the joint faces, using coarse paste on the outer lands and fine on the cylinder spigot face
This leaves a minute gap on the outer faces so the pressure of the holding down bolts is on the inner faces
Do a search for the BSA service sheets that will show you all the servicing and rebuild info

John

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Thank you.

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I have buily many B31s and B33s never sealed the heads just lapped them in


A7, A10, B33, B31, A65, C15, T100
Bantam
1 member likes this: leon bee

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