Thread: ring gap questions

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Originally Posted by jimmyjeep

Interesting. Well at this point I'm in favor of testing each bore for taper, trying to nail the .016-.018 for the top ring, adjusting the 2nd ring and run a standard oil (vs. low tension). Unless someone sways me from here, thats how I'll work it for now. I wonder how Eric does his???

If you're going to open up the second ring, make the gap 1.5 to 2 times wider than the gap on the top ring. That's what the experts recommend. Also, pay close attention to the procedure used to hone the bores. Here's a blurb from Speed-O-Motive:
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When installing new rings, the single greatest concern is the cylinder wall condition and finish. If the cylinders are not properly prepared, the rings will not be able to perform as designed. The use of a torque plate, head gasket, and corresponding bolts are necessary to simulate the stress that the cylinder head will put on the block. Main bearing caps should also be torqued in place. The correct procedure has three steps. First the cylinder is bored to approximately .003" less than the desired final size. Next it is rough honed within .0005" of the final diameter. Then a finer finish hone is used to produced the desired "plateau" wall texture. Use a 280 - 400 grit stone to finish cylinder walls for Plasma Moly rings.

Note - the "grit" number we are referring to is a measurement of roughness, it is not the manufacturers stone part number (a Sunnen CK-10 automatic hone stone set #JHU-820 is 400 grit). The cylinder bores should be thoroughly scrubbed with soap and hot water and then oiled before piston and ring installation.

Piston ring grooves are also sealing surfaces, and must be clean, smooth and free of defects. Ring side clearance, measured between the ring and the top of the groove, should be between, .001" and .004"."

Jim, I'd also advise you to go with the high side of the spec on top ring gap. If you get a little more gap than you might think you need, it's not going to make a huge difference in the way the motor responds. But if the gap is too tight and the rings end-butt, you are looking at doing the whole thing over again and if the bore is already at max, you're looking at finding another block before you can begin. Err on the side of caution. Be sure and follow the manufacturers instructions to the letter. If they don't give you an end gap figure, get on the phone and nail it down for sure.