|
Brian Elkins wrote: > Looking down on the top of > the piston there is a ring around the outside approximately 1/8" wide, > from there it "steps up" about 1/16". After the step there is a > slight flat portion on one side and a slightly wider flat portion on > the other side, after the flat portions there is a very slight bevel. > After the slight bevel is the flat portion of the piston which takes > up approximately 50-60% of the piston top. You have the correct pistons. > Unfortunately the liners show some signs of scoring. The scoring does > not appear to be any deeper than what you might expect from normal > honing (you can feel it with a fingernail) The first step, then, would be to hone one liner until the scoring is cleaned up, then measure its bore diameter. The increase in diameter, added to the inevitable wear on the pistons, will possibly make replacement pistons necessary, but that's not a given. If the clearance is within tolerance, but towards the high end of the range, one trick I have used in the past that works extremely well is to have the piston skirts microknurled, then dress them with a file until they are a slip fit in the liners. This has the advantages of minimizing piston rocking and retaining oil around the skirts, while keeping sliding firction to a minimum. I would only do this if everything is in good condition, but with slightly high piston-bore clearances. > Two of the piston tops > show some pretty severe dings where the hardware "danced" around for a > little bit. They may still be OK. The way to verify this is teardown, inspection, and measurement. > I emailed Ray and he said he no longer had the parts available. His > recommendation was French Stuff in California (I haven't contacted > them yet). I contacted Tingles and he quoted me a price of $960 > (piston/liner/ring/pin) but I've been told that sounds on the high > side. When Ray could still get replacements a bit more than two years ago, his price for a complete liner/piston/ring/pin kit was $810.00. If Don is sourcing the same parts, it's not surprising that the price would have risen by that amount. I wouldn't consider going that route, as the exorbitant price isn't buying you anything you can't improve on for substantially less money. > Lee (the other Utah Euopa owner) told me about a place > (www.mecaparts.com in France) that has replacement Renault parts and > the kit was approximately $400 US (I imagine these are the Renault > pistons and not the Lotus pistons, it would be great if I was wrong > though!). Renault sources _cannot_ supply Lotus pistons. Don't even bother, you just won't find them that way. > I also contacted JAE and I was told they have forged > oversize pistons and rings for fitting to a bored liner at a cost of > approximately $550. Sounds like the Wisecos. That's not too bad a price. > The machine shop owner told me he can get all the necessary parts but > I'm not sure if he would be getting Renault or Lotus parts. Don't leave it to him to source the pistons. Sounds like JAE is your best bet. Ask them how much the pistons weigh - the used OEM ones John Abbott loaned me for patterns weighed 414-416 grams each, the Bretille replacement (the ones that r d sold) weighed 448 grams, and the .020" over pistons I had Wiseco make weighed 417 grams. I understand that Wiseco requires a minimum purchase of two sets now. If you can get another lister to go in with you, you could buy direct from them and save yourself $100.00 or so. Another issue: the groove for the oil control ring on the OEM pistons is a weak spot. The tops have been known to break off in that area. I would not expect similar problems from aftermarket pistons. Jay |