[Wonderboy]

Another small update:
I went back to the racing shop that did the valve job on my head (they encouraged me to come back whenever I wanted - they enjoyed talking to me about my aero mods and FE in general) and talked to a very knowledgeable guy about gapless rings. He reassured me that totalseal was the only place where gapless rings available if Gasoline Fumes' research holds true (that there are no longer any more OEM gapless XFi rings in stock from GM parts suppliers). He said that I should measure the spring force of the old rings vs. the new ones using a fishing scale or similar spring scale by seating the rings into a cylinder, then pulling on the scale. There should be a spec somewhere for the force required to move a piston - does anyone have this? I also talked to him about using the 75mm honda ring and making my own gapless ring. He said it was actually a pretty good idea, and that it would produce more spring force (= more compression?) than the stock 74mm bore rings would. I assumed this to be the case, and was only reassured. He said to do exactly what Christ advised - seat a 75mm ring into a cylinder, mark off the overlap, then add at least .007" to that to leave wiggle room for heat expansion. I asked if the large radius of the grinding stone used to remove ring material could cause any issues, but he said nope, as long as the outermost points of it were at least .007" away from the other end of the ring. I made a picture to demonstrate this. By exaggerating the scale, I hope it illustrates what I'm trying to say. I hope to try it out as soon as my experiment rings arrive.

Originally Posted by bgd73

and you geo owners. for god sakes..remove egr before doing it?

I dont think any of the 1.0l G10 engines had EGR, right? At least I'm pretty sure my xfi doesn't - out of curiosity though, how exactly would retrofitting a gapless ring affect an engine equipped with egr? I'm clueless and wouldn't mind learning.

Originally Posted by zoltanbod

Do you know of any varifiable evidence as to the efficiency improvement reported using the gapless ring on the Suzuki 3 cyl.?

I don't have any first hand accounts to give you, but I can tell you that the XFi motor only has ONE compression ring per cyl. The fact that the XFi (combined with a different ECU, a more efficient cam shape, and some body weight reduction) yielded significantly higher fuel economy than a stock 1.0l is verification enough for me that the gapless ring was used on the XFi for a reason. I assume that reason is reducing cylinder friction while reducing any blowby liable to occur using standard rings.

I couldn't tell you what kind of change you would see if you were to remove all the 2nd rings from a stock G10 and added gapless top rings, but if it resulted in an efficient gain, I'm almost certain it wouldn't be as significant as swapping the cam out and getting an advanced timing sprocket, which can both be found here.