BSA Owners' Club Workshop Discussions

The BSA Workshop => Singles => Topic started by: courtney on 17 Jul, 2021, 13:42

Title: C15 piston rings
Post by: courtney on 17 Jul, 2021, 13:42
Hello,

I'm replacing my piston rings on the C15 today. Opening the packet, there's a octagonal spring ring type of thing. I didn't have one fitted before. Does this go under the oil ring before it's fitted in the groove of the piston? It's got holes in it the same as the oil ring. Rings are from Draganfly.

Any help appreciated, thanks.
Title: Re: C15 piston rings
Post by: Bess on 17 Jul, 2021, 18:54
Hi,
    I would ask Draganfly, they are very helpful. Oil scraper expansion rings are normally spring like, although from distant memory I've seen different.

Or I would fit it into the lower piston groove and see if the ring fits over and the compresses enough to allow the piston to fit in the barrel then its probably okay.

Best wishes...
Title: Re: C15 piston rings
Post by: idie on 17 Jul, 2021, 19:00
They are normally there to impart more pressure on the bore.
Title: Re: C15 piston rings
Post by: courtney on 18 Jul, 2021, 23:40
Thanks both for the suggestions. My thinking was that it went in the lower groove under the scraper ring, but doing it there's no way it will compress enough to go in the bore. I'll call Draganfly tomorrow and see.

On a side note, I'm annoyed I spent ages uploading a photo when there was already one on the Draganfly website!
Title: Re: C15 piston rings
Post by: courtney on 19 Jul, 2021, 09:56
Called Draganfly this morning who were very helpful and put my mind at ease. It was clear it went under the oil ring to provide more pressure against the bore, but it's not necessary for my application. If you've set the ring end gap it messes this up and you can't fit the piston in the bore. The only way I can see it being of use is it the groove in the piston is deeper for some reason.