anyone have experience with ring gaps? I have file fit rings I am about to file and I cannot decide how much gap to go with. According to the chart I got with the rings, There is a N/A gap and of coarse a wider gap for blower applications, since I will be pushing about 15psi estimated with this engine I believe I want the wider gap but my only fear is oil consumption during normal driving. Anyone that has done this before have any advice? I don't want to be adding oil frequently because I have a ring gap that is too wide.

 

it wont burn oil, the top 2 rings are compression rings and the bottom one controls oil. u got to file them or the rings will butt together and tear the top off a piston.

 

definitely use the wider gap without a doubt, check the oil and if it uses some, that comes with a blower motor

 

Acording to Speed Pro:

Cast Iron or Ductile Iron Rings in nitrous (drag) applications

.007 per inch of bore
.028-.030 with a 4.000"

This is wider than the supercharged alone. Make sure you use them same torque plate and head gasket when you file the rings, as when it the block is bored and honed.

Federal Mogul's Tech line is 1-800-325-8886

 

My rings are gapped for nitrous and it doesn't use any oil.

 

really... i am running .028 end gap on my KB hypers. on a N/a engine

didnt see him mention that he had speed pro pistons... actually his sig says JE... so what ever # speed pro says is worthless along with thier tech line unless you like being placed on hold only to be told that you need to call the piston mfg.

 

I actually got the gap numbers from summit.

 

Most radial ring thickness's are based upon SAE D-wall specifications. lateral gap between the piston and the ring is also based upon SAE specifications. Both Speed Pro and JE are based upon these.

Radial thickencess = (bore diameter)/22

But, yes i didn't notice he's running JE, probably would be wise to call them on an acceptable ring gap.

 

okay so what does that have to do with his endgap on forged JE pistons and even the mfg. only gives a recommendation or a minimum because they have no idea what kind of insanity you are planning for an engine but at over $600 a set i would go bigger then they recommend probably not much though

 

its better to be on the big side than on the small side.

 

i know i would rather buy a quart of oil every month or so than be buying a new set of pistons!

 

Thanks for the tips gentlemen. I went by what my paper recommended that came with the rings and after some of my own google research. I ended up going with a 24 on the top ring and 28 on the second ring and of coarse the 61 on the oil ring. this was for a 4.03 bore so its like .006 and a .007 and .015

This sound good to you guys?

edit: for the record my paper with the rings recommended .0055 and a .0065 for blown applications so I opened them up a lil bit more.

 

sounds like a plan, make sure to install them offset 180' for the top 2 rings

 

yes of coarse, I would hate to mess that one up.

 

I'm a bit late, but KB has a nice write up with explanation on their website. Basically they did a .080" ring gap (yes, HUGE!!!) and oil consumption was barely noticeable. As mentioned, the oil control rings take care of that. Bigger ring gaps save you from beheading the piston at the ring land.
I think I used .025" on my NA motor, just in case I ever decided to run nitrous. I can now run a 150HP shot or so and sleep well at night.

I'd run the bigger clearance on the top ring, since that's what sees the most heat. I think you're just on the edge, if it were me i'd go higher, ~.030" on the top ring. But that's just my wild assumptions there