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Bikes, Pictures, Stories & more => Other BSAs, Other Bikes, Cars, Machinery & Tools => Topic started by: Guy Wilson on 30.07. 2019 13:54

Title: B33 oversized piston
Post by: Guy Wilson on 30.07. 2019 13:54

BSA B33
I bought a plunger B33 in pieces..most were in gunny sacks... I have a barrel with an 88.4mm diameter but no piston.. Does any one know what oversize piston would fit? Would it be an 88mm ? The bore is good so I was planning to use it as is..
Many thanks
Guy

Title: Re: B33 oversized piston
Post by: RDfella on 30.07. 2019 16:12

That's way past max oversize of .060" (86.5m,  85mm = std). Maybe needs a liner?

Title: Re: B33 oversized piston
Post by: Guy Wilson on 30.07. 2019 16:17

thank you, I was just trying to figure out why the bore is so big.. VW beetle pistons fit well on the M and B series engines and go up to 90mm in diameter. It may have had something similar in at one stage...It wasn't in the bottom of the sack though.. I liner might be the way to go..

Guy

Title: Re: B33 oversized piston
Post by: duTch on 30.07. 2019 21:50

 I think I recall someone I knew used a XT Yammie piston in theirs....long time ago *conf2*

 ** Afterthought- maybe it was in a M21