Just thought I would share a little bit of new to me knowledge. I put a shallow dimple liner in my ported stroker facing the way the book indicates and it went out with a cloud of white smoke with twenty something hours on it. So what I have since learned is that with the aluminum nikisil liners the dimple goes to the front from now on. Iron ones need to go with the dimple to the back because they are torque bored and honed. Boomer sent sleeves with no dimples at all which make me feel much better. Ray
Thing is those liners were bored in a fixture with dimple facing the back(torque bored).That fixture duplicates what happens to sleeve when head is torqued.They distort alot whether castiron or aluminum.Only way to spin a sleeve with deep dimple and guarantee there wont be tight spot in piston to liner would be to resize the sleeve out of the fixture with a diamond hone.What you would then end up with is a very loose fitting piston.But it would be safe to spin the liner.Shame since benefit of our liners is long life of piston and liner possibly more hp also since you can run tight tolerances.Something you can never do with a cast Iron liner.In my opinion if it has a deep dimple it is junk.
Check the sleeve for porousity where it cracked. Early cannondale sleeves made by millenium were forged and much stronger than the later ones. They were made in a fixture which simulated an assemble sleeve.They were striaght when assemble in the case and disorted when out hence the needing of a location dimple. Newer ones are a cast aluminum liner which may have porousity.Very rare for a non deep dimple sleeve to break. The newer liners ae not nessesary to have the dimple lined up because are made straight. They do distort when assembled about .002-.004. The cast sleeves and also the aluminum nicasil 97mm ones do need to be lined up with location dimple. Cast sleeve for the most part are finished in press fixture, also the 97mm ones I sell which are forged and finished in a fixture. They both will check distorted out of the case and straight and true when installed with a press. As for the new 95mm nicasil aluminum it doesn't matter. The better old forged ones were last used in the fx's and mx's made by millenium and are long gone. Sleeve's were then made oversea's by asso to save $. An important note for people rebuilding motors is never to use silicone on the head gasket or will crack the sleeve.The grove is made for just enough space for the o-ring to compress, anything extra in the grove(silicone) can cause damage.
Here is some pretty good pics of the liner.. notice that the dimple is no deeper then the point of a drill bit. I run evans coolant and use no silicone on any of the liner seals, only an "O" ring lubricant. Twenty something hours on a ported 2.2 stroker.
Here are other dimensions. Had a known good sleeve measured at work on thier Comparator. You can see a bit of shallow dimple on it. [attachment=5630:Oring_cyl.jpg]
I have a used sleeve that came out of the builder motor I got from zack... that one is what I call deep, maybe I can get a picture for reference. Cant remember exactly who I got this liner from, it was a regular to the boards. It was installed once but not run. I guess it does not matter but funny how the memory fades! I do remember he called it a shallow dimple. So maybe this is more like a medium dimple but it is definatly not a deep dimple. Ray
Yea all kinds of depths. I always think of the person chewing away at a piece of gum talking to everyone and pulling the handle on drill press. I imagine it got so boring that they could do it sleeping and maybe did for a WHOLE DAY! Working in a factory you would be amazed at some of the mistakes that happen.
