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New Piston Source Red Lizard


Well Known and Active Forum Website User
Non-VOC Member
Those pistons are made by JP in Australia. Stay away from them as they are not cast from silicon aluminum and will have to be installed with large clearances or else they will seize.

I put a pair of their pistons in a customers A65 BSA and had to use .005 clearances. With the soft aluminum used in them I know the engine will have a cold piston slap with less than 15k miles on it.

John Mead


Active Forum Website User
Non-VOC Member
Piston Alloy should be LM13 10 - 13% si and quite a tight spec on the other elements, we used to make the odd batch years ago the Nickel content was also important.


Well Known and Active Forum Website User
Non-VOC Member
JP pistons are made from silicon aluminium and thorntons uk have been selling them for years

Then why do you have to run excessive clearances or they will seize. I have installed CP Pistons (California, USA) in Vincent twins and only used .004 clearance. The BSA twin is 75mm and they have to be installed with more clearance.


roy the mechanic

Well Known and Active Forum Website User
VOC Member
Thorntons (shrewsbery) have supplied me with J P pistons for many years have fitted them in all sorts including Bentley, Alvis, B S A . they are not forged like you get from Venolia or omega but they get the job done effectively provided you have the expertise to know what to do!


Well Known and Active Forum Website User
VOC Member
Just found a supplier in the Isle of Man selling pistons called Red Lizard Classic Motorcycles.

See http://www.classic-motorcycles.co.uk/cgi-bin/ecom.cgi?Command=ListProducts&db_scid=132

Vincent pistons at £131.15

Has anybody tried them? I'm thinking of trying one their Sunbeam ones


For comparison I had a venolia piston made for my 600 methanol motor I took a piston added Plasticine on top molded it to shape I wanted anointed it with castrol R to harden it sent it off to USA got it back with a new piston for less than that quote above (got a barrel bored to suit piston later)
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