My wisco 1015 pistons with numbers on the dome came with instructions that say the clearance for the pistons are .0015" - .0025" / 0.04 - 0.06mm .. The ring end gap should be.004" for every inch of bore size ie: 1015 is about .012"..
suggeston.. think about having the skirts and dome coated. I had mine done and it cost about 160.00 for the set. The skirt coating relieves the friction on the walls and the coating on the dome gives a better, more unform burn in the combuston chamber as well as protects the piston from the heat. contact Carl at
www.polydyn.com
(I think that is the address). B)
