Blue Star W34 crankcase gasket

[David Samways]

Can anyone tell me if BSA fitted a gasket between the crankcase halves on 1930s models with the the built-in oil tank at the front of the crankcases?

It seems somewhat unlikely that they didn't fit a gasket but there's nothing shown in the parts catalogue, but it doesn't show gaskets for the timing chest either (and there must have been one there).

[mark quinney]

 Hi David
May not be a lot of help to you but I have a 32 BlueStar that has no sump gasket that I can see ( I haven't had the sump apart but there are no signs of any gasket around the joint ) also there is no gasket on the timing chest , I have had the timing chest off and it  just add a layer of gasket cement / silicone  which I replaced with no leaks so far  .  Also checked my parts list and it as no sign of any gaskets ,  may be worth you phoning one of the BSA  spares suppliers as they may be able to help
Regards Mark

[David Samways]

Thanks Mark. I think all of the British engines I've assembled in the past had no gasket on the crankcase faces - I've used Wellseal and silicone in the past. I wondered if the Blue Star might have a gasket due to the oil reservoir, but I think you must be right and there never was a gasket. I wonder what BSA used to seal back in the 30s?

I'm slightly surprised about the timing chest, partly as every machine I've owned has had one in this position, and partly since as assembled when I acquired the machine the engine was stiff due to the timing gears having insufficient end-float with just Hylomar as a seal. You are right though, nothing shown in the parts book.

I shall assemble the crankcase with Threebond sealant and experiment with the timing chest - easy enough to make a thin gasket for this position.