piston help please

Started by chimp koose, November 23, 2020, 10:38:51 PM

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chimp koose

So I am machining wider ring grooves into an OLD set of pistons for an inline 6 cyl hemi destined for a 46 willys jeep , for a friend . The first one is going great . I am turning the spindle by hand as I cut the groove and then things get tight . I made a tool just the right width for the groove so this is bad . I have dialed in the piston , dialed in the existing ring face and all should be well ....but . I remove the tool to find a chip wedged beside the cutter that has now made the groove .010 wider than I wanted  :evil: . Question is this . can I use a ring spacer like an oil ring spacer under the top ring to take up the extra ? Like machine the ring groove to take the top ring and oil ring spacer plus clearance ? I know they do it on diesels . From what I gather this is a rare engine .

enjenjo

With the beating that diesels take it should be no problem for a gas engine to have a ring spacer. Make sure it doesn't stick out from the ring groove.
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chimp koose

Thanks for the reply! The oil ring spacers are very low tension but do stick out a little . Owners idea to machine /locate the piston was to slide it into a split tube and chuck it with the oil ring holding it square . The oil ring would not hold it square as it barely would catch the edge of the tube. I really feel stupid as the cutter lacked the proper clearance on the one side and was rubbing as I got deeper into the groove  :oops: I was very careful and as I said I was turning the chuck by hand . I had even narrowed the cutter to just behind the cutting edge . The tool holder was from a different lathe and was sitting at just a slight angle that negated the clearance when the web of the cutter got deeper from top to bottom.

kb426

I have used sealed power ss50ou oil ring parts for spacers before with good success. Some of the * top rings I used also had spacers for different grooves.
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chimp koose

I had a spacer/blocker ring in my total seal set but that was in the second ring groove .  I remember the * stuff as you could use ti in an existing ring groove or cut a narrower groove closer to the top of the piston and drill holes/gas ports to the back of the groove to load up the ring . I thought the oil ring thing would work but have never tried so thought best to ask. Thanks again guys.

chimp koose

Talked to my buddy and all is well . We will use the oil rails under all the top rings as a kind of home brewed zero gap deal. Thanks again for the helpful responses . When it first happened I was just a wreck , I thought these were the only pistons he had but as it turns out he has many sets . I thought for a while that I might have to make a piston. :oops: