I am gettin ready to gap my rings using perfect circle 40564CP. the indtructions suck. I need to know what ring if for the top and what ring is for the bottom?.. the only diffrence I see is one had a angle cut on the indise edge and the other is square. also, the dimple is a litle bigger on one set.

also, does the dimple always go up?.. in the picture it shows the dimple up, but then angle is on the bottom them, but with the dimple up the angle is at the lower insde edge..

Thanks

 

One should have a shiny outside edge and one a duller edge, although I can't remember which is top and which is 2nd, so I guess that isn't much help, lol.

I'm pretty sure the dots go up and the tapered one is the middle ring.

http://circletrack.automotive.com/75...rep/index.html

 

ahHH. I figured it out. it was printed on a stupid part of the box.. one the little flap on the box.. anyway. know top and bottom now. and im prety sure dimple goes up.. btw the shinny ones are the top

thanks

 

Yeah, dimple goes up and the shiny ones are the top rings. They have a special coating or something. I remember now...

 

Are these a "file fit" ring set? If sooooo ....... would you mind telling me what the "as received" (i.e. un-filed) ring end gaps were on these in your (I'm assuming 4.030") bore?

Also, what ring end gaps are you shooting for on you build?

 

None of the descriptions online say if they are file to fit or not, but I'd assume they aren't since that isn't specifically mentioned.

BTW, I hope you bought yours from summit. Everyone else seems to be charging almost twice as much.

 

It is a 4.030" bore.. I just insalled a few of the top rings and centered them up with a piston and measured the gap, the top rings from the factory came with a .012" gap.

I am still debating on what exactly to set my gap to. For the top rings, I know at a very very minimum to use .004" PER inch of pistons (4.030 X .004 = .016") but I want to run some nitrous, so I have heard to run .0045" per inch with a litle nitrous use (4.030 X .0045 = .018"), even these seem a little tight for my comfort. I see people on here running .028" and .030" on the top.. for example "Ring end gap on a performance N/A motor that has a 4.030" bore will be somewhere in the .020" range (top ring). Ring end gap for a nitrous motor with the same bore will be approx. .030" for the top ring...HUGE difference."

I am still debating..

 

I know there are two(2) distinct "schools of thought" on this but ... are you considering setting your second ring gap larger or smaller than your top ring gap?

 

I like the big gap in the second ring, its been working very well for me for the last few years or so since I started doing that. My 355 is gapped at .022" top and .026" second. I like a little larger gap for higher compression, and also depending on how far down the piston the top ring land is.

 

I have always heard 10-20% larger on the bottom ring.

 

Whatever you do just dont set them up ultra tight. Too tight = broke parts. Too loose = maybe a very tiny chance of some leakage until it gets warm but probably not.

 

yea, thats a good call.. also I called perfect circle again and got someone else, and he said that ppl put way way to much emphasis on gap, he said as long as it does not touch, and there is not a HUGE gap (.080") there wouldnt be a problem.. so I took that to heard and used my dremel tool and gaped those bastards to .025" on the top, and .030 on the bottom.. so, there it is.. cant take it back now, its how its going to be!.. :-)