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Mazda 2.2L \  Piston ring gap

Piston ring gap

Mazda 2.2L Mazda Engine Mazda Tech
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replies 13
following 3
 
Slammedbeez   +1y
New member, also first time doing a rebuild so excuse my rookie question. So I purchased dnj std piston rings, was reading up on ring gap for the b2200 and it said .008-.014 for top ring. I measured it with a feeler gauge and .008 fits in the gap, and when I measured it with the .014 it wouldn't slide in, do I need to file it a little to allow the .014 feeler to slide through? And do you usually gap std size piston rings? Thanks in advance
Cusser   +1y
If specifications are.008-.014 for top ring and you measured it with a feeler gauge and .008 fits in the gap, and 014 doesn't: then you are within the specification. So don't do anything, you're good to go, you actually did that measurement correctly. If you file for 0.014 to fit through, then the gap will be too large.

Figure "if" 0.011 is "perfect", if machines and humans were "perfect", then range might be 0.010 to 0.012, would to to tough to meet such spec. Basically, anything within the spec if fine, and one value within that is not better or worse than another. If you're a real detail person, you could use an interim feeler gauge to measure what the gap really is, and write all that stuff down.
Slammedbeez   +1y
Awesome, thanks cusser. I figured it had to be correct, just needed a second opinion.
geterdun   +1y
Where did you have the ring in the cylinder when you checked the gap?
Slammedbeez   +1y
I checked it at the top and bottom of cylinder, and .008 fits in the gap at bottom as well
geterdun   +1y
At the top, did you have the ring above the area that the ring rubs on, that 1/4-5/16" area that is above the ring on the piston, or more correctly, the original cylinder bore, since a ring has not touched it, except when the piston was tapped into the cylinder to bolt up the rod cap?
You can use the inverted piston to push the ring down evenly into that area at the top of ring travel up the cylinder to check the wear (ring end gap). Ideally, use a bore mic or telescoping gauge and mic to check bore size at the top of ring travel, perpendicular to the crankshaft. These blocks are really good metal, so you are probably going to be good.
Just don't use a dingle berry hone, it is a joke. Ideally use a Lisle 15000 rigid hone to true the cylinder, but a good spring loaded one should be fine on these blocks. Don't forget to get a good cross hatching after the honing for ring set.
Slammedbeez   +1y
I had the block honed at a machine shop, had them go through block, cylinders were in good shape, and the top ring i put in the cylinder, inverted piston to push it down and square it up, pushed it in about an 1" from the top and took measurement, then just pushed it down to bottom and took measurement
geterdun   +1y
Sounds like a build and a coupla hundred thousand miles are in your future!
Slammedbeez   +1y
Yes I hope! Truck was smoking at start up with 175k, thought it was the oil rings, pulled pistons out they looked all good not stuck, so I figured it was the valve seals, since I had dug into the motor that far I thought I'd just rebuild it completely with everything new
Johno   +1y
hi sorry my first time on site how do I ask a q on this site?