Gasket for base of barrel/crankcase interface

Started by oggers, November 13, 2023, 10:25:55 PM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.


I just stripped my engine and there wasn't any sign of a gasket and no real sign of leakage, though it had been sitting for many years.



I think some sort of gasket is required. The mating faces are good and I cannot see how I cam improve things with just grease and no gasket. I think I'll try 1/4 mm Flexoid with some Permatex sealant. if I go any thicker there may be a risk of the rings coming into contact with unworn parts or ridges of the bore.


The book says only grease is needed, I used Wellseal.
Also check that there are no digs where the cases join just in case the joint face is not  quite flat.

John Hood


I applied an 0.5mm paper gasket and it was fine. However, I still have a tiny amount of oil at the joint. Maybe an additional thin layer of Hylomar on both gasket sides helps.
1946 BSA C11
1937 Sunbeam Model 9
... and a scratched Hyundai
(MSCR member)



A small amount of oil was leaking between the base of the barrel and the top of the crankcase on my 1932 Model 9. Not much, but annoying nevertheless. Removing the barrel revealed a paper gasket? smeared with some sort of sealant. Not great - see attached pics.

Does the club have a spare gasket I can purchase?

Otherwise, I guess I'll have to make one. Would 1/2mm Flexoid do a better job or does it need to be paper thin?