Hello, I recently stripped two WM20 engines. One had silicone casket between crankcase halves other had some old paint-like hard thing. What was genuine casket? What will be best nowadays? Thanks for sharing your knowledge.

Kalle

No gasket, just your favourite goo used sparingly. You don't want gobs of silicone extruding into the cases.
Cheers
Pete

email (option): petercomley@web.de

Hi Kalle..I use sparingly applied silicone sealant...Ian

email (option): ian@wright52.plus.com

I always use blue silicone gasket myself. For my faithful old Citroen 2cv they used raw linseed oil at the factory as crankcase gasket, would they have used that for BSA crankcases too back then?

Henk.

email (option): ahum@quicknet.nl

I think the given jointing compound in those days was Shellac
Ron

email (option): ronpier@talk21.com

Hello Kalle,

I think the paint thing you found (Deep brown?) was “Shellac”.
This is what I use to apply on gaskets and to seal bottom case.

Its super strong as glue, and if you have any extras on sealed surface,
it does not tend to be torn, fall inside and get into oil ways.

Noam.

email (option): noam10@gmail.com

Came across several cases that had a bonified paper gasket. But I thought these cases never used them. They did not look homemade.

I see also, that at one time, there was no copper nor asbestos gasket used on the head.

email (option): unpob@yahoo.com

More information on those two points please Henri...I am unaware of any crankcase gasket to date and would be interested in further information about when these engines were run with no head gasket..a very unusual practice!....Ian

email (option): ian@wright52.plus.com

During a trip here in Holland one of the guys had a leaking head gasket of the copper asbestos type and just removed it and along we went. No problem at all.

Henk.

email (option): ahum@quicknet.nl

Hi Henk...Yes, it is entirely possible to do this..but I am interested in whether this was ever applied by the factory as Henris post might infer, or was this just a 'one off' observation he was making about a particular engine?...Ian

email (option): ian@wright52.plus.com

Hi Ian, I may have misread/missunderstood what D.W.Munro spoke of. The chapter is on the Cylinders. The book is great and is named "A Practical Guide Covering All Models From 1931"

When reading the para, it mentions metal -to-metal cylinder-head joints, without the interposition of copper-asbestos washers...reading it now, it says washers, so maybe he was talking about the valve guides. Not sure, but it did seem to be implying cylinder to head surfaces. Here is the photo of the page at the risk of infringing copyrights

email (option): unpob@yahoo.com

Ian,

It was a post war early 1950's that I remember and that is now closed up, but there were two others that I ran across and tried to find out the replacment gasket number only to find out that it was not used. Scratched my head on that one. Sorry that I am unable to provide photos.

email (option): unpob@yahoo.com

Hi Henri,

Yes metal to metal was applied on pre war OHV engines. The head was machined to have a groove in which the cylinder fitted. These were the faces you were meant to grind in with valve paste. It works fine on the OHV engines but such machining was not applied to SV engines as fas as I am aware of.

Regards,
Leon

email (option): leonhop3@planet.nl

Thanks Leon,

HT.

email (option): leonhop3@planet.nl

Also used on WB30s and post war B31s/33s and M33s..Ian

email (option): ian@wright52.plus.com

maybe you could use that copper grease only that was dicussed for use on solid copper head gaskets on this forum

Thank you for confirming my thoughts that silicone sealant is good enough for this job. I have used silicone everywere on my russian SV boxer exept heads.