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Motorcycle Discussions => British Bikes => Topic started by: VintageBike on May 26, 2008, 11:52:35 PM

Title: BSA A10 Head Gasket
Post by: VintageBike on May 26, 2008, 11:52:35 PM

I have been asked a question that I need some help with..  I understand that there are two alternative head gaskets available for BSA A10s - solid copper and composite.  Can anyone advise on which models/years these should be used - or are they interchangeable? In particular I am interested to know which is right for a 1951 Golden Flash

Thanks for your help.

Nigel.

Title: Re: BSA A10 Head Gasket
Post by: Blue on May 27, 2008, 04:42:01 PM

Use solid copper for all models.  For a low performance, mildly tuned A10 you can use composite gaskets (usually copper/asbestos) if thats all you have, but you're much better off using the gasket as a pattern and cutting one out of copper sheet (1mm is about ideal).  The early semi-unit A10s had skimpier finning and a thinner flange on the base of the cylinder barrels, but I'm pretty sure the head gaskets are the same pattern.

Just remember if you use solid copper you must anneal it first (heat to cherry-red then quench immediately in a bucket of water).  This isn't necessary for composties.