I was assembling my piston rings today and happened upon something I hadn't seen before, which comes with a back story... When I picked up my block and assembled piston/rod assemblies from the machine shop, the shop owner handed me a bag with oil control rings in it. It is a package of rings, 8 in all, which he instructed me to use as the lowest of the oil control rings... "they go on the bottom" he said. Okay, I didn't recall providing him with any rings as the kit I purchased had the rings separate from the rods and pistons. Regardless, I take everything home. Today I decided its time to install the rings on the pistons. So the first thing I reach for when assembling the oil control rings is the packet provided by the machine shop guy. I notice they are different than any I have used in previous builds. They overlap at the ends and are very difficult to pry apart and install on the piston. So I do the first one, then open the pack of oil ring parts provided in my ring kit. I immediately noticed the difference. The ones from the kit install easily, which is consistent with all my prior builds and I make quick work of assembling my oil control rings. I now have 1 left over ring from my kit, and 7 left over rings from the package of mystery rings. So this gets me thinking..... did my engine guy hook me up with a better set of lower oil control rings? Did I overlook the set of rings when I dropped the pistons and rods off for assembly? It is obvious the mystery rings are not for either of the upper grooves, so I ruled that out immediately. I don't like questions when it comes to engine assembly, so I suspend work until I can get some answers. Naturally I will be calling my engine guy when he returns to work, however figured I might ask the question here as well...... has anyone else had experience with oil control rings that overlap, are thicker than normal and subsequently more difficult to install? I am certain to get an answer on Wednesday and in the meantime I have plenty to do. NYE partying comes to mind first and foremost, so it isn't an urgent problem. Additionally I have until March to complete the build, which is pretty much down to assembly and installation. I do have manifolds out for ceramic coating and an intake out for powder coating, but mostly all that's left is assembly and installation. Sorry, no pics of anything as I am a computer tard.
Is it possible he gave you a lower oil ring spacer for an "interrupted" piston compression height(piston pin intersects part of the piston's oil ring land). This may help with description:
That is exactly what it looks like in the video aquartlow. The issue I had on first attempt was there didn't seem to be enough space in the oil ring groove to accommodate the spacer, the two outer oil rings, and the expander ring. Ill give it another go and see if I can make everything fit.
NO oil ring should overlap when installed - NEVER. With some pistons (mostly stroker) the oil ring intersects the pin hole (as stated previously) and requires a "support rail" which, in uninstalled form, overlap. These rails will have a "dimple" which would be placed in the pin hole opening, with the dimple facing down. Then you would assemble the oil rings as usual. Brand of pistons? Part number? Part number of the ringset? Application? Holler - I own an automotive race engine shop, might be able to help.
Its the spacer, not the oil ring, that overlaps. Specifically, it overlaps itself prior to installation. Once installed it fits nicely. You call it support rail. That sounds right. Sealed power speed pro pistons, Hastings ring set. Too lazy to walk out and read the part numbers off the box, but they were purchased as part of a balanced rotating assembly kit from Jegs for my pre-86 289 winsor. Oh, and I was able to get one piston completely assembled. Ill tackle the rest next year.
