alexander Posted May 22, 2005 Report Share Posted May 22, 2005 I bought new piston and liners from a well known supplier at the Stonley Triumph Show. I've assembled one and checked clearance and find I have .010" all round the piston top. The manual says max .007" any more change for new. Has anyone else had this problem, I'll give the supplier a call on Monday and see what story they have. thanks Alexander Quote Link to post Share on other sites
marvmul Posted May 22, 2005 Report Share Posted May 22, 2005 This is a normal clearance at the top of a piston. It can be more than that. The skirt of a piston is not straight but more like a barrel. Quote Link to post Share on other sites
alexander Posted May 22, 2005 Author Report Share Posted May 22, 2005 Hi Marvmul thanks for the reply. I've just check a piston for size:- top 3.364" middle 3.384" bottom 3.384" The liner is 3.386 top and bottom , could not measure middle as vernier would not reach, does this seem Ok to proceed with build. One other point the pistons do not have the slot that is shown in the manual running down the piston shirt, but does have holes in the oil control ring grove. Does these holes replace the slot as I assume both the slot and the holes are for lubrication. thanks for any help Alexander Quote Link to post Share on other sites
marvmul Posted May 22, 2005 Report Share Posted May 22, 2005 Alexander, the slot is intended to let the piston expand by heat in a certain way, to avoid that the piston gets a bad shape by expanding, thus preventing that pistons would dig in the liners at some area's. The holes are for lubrication, to drain the scraped oil to the inside of the piston skirt. Quote Link to post Share on other sites
alexander Posted May 22, 2005 Author Report Share Posted May 22, 2005 Thanks again Marvmul does this mean that the pistons I have could be a problem if I use them or should they be OK Alexander Quote Link to post Share on other sites
Guest barry100 Posted May 23, 2005 Report Share Posted May 23, 2005 Hi Alexander The skirt of the piston is the part to be measured , with a feeler guage,but because they have different types of pistons/skirts they will have different clearances depending on the type fitted,should think the split skirt would be a tighter fit. according to my book its .0032-0039 for the spilt skirt at the bottom of skirt. Barry Quote Link to post Share on other sites
marvmul Posted May 23, 2005 Report Share Posted May 23, 2005 does this mean that the pistons I have could be a problem if I use them or should they be OK No, some pistons do need such a slot, some don't. I believe, most modern pistons don't have such a slot. Quote Link to post Share on other sites
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