oil blow-by

[FB71]

if its got blowby after a bore/hone, then the wrong (too coarse) stones were used. Should be finished with a 320 stone set, then plateau honed. Probably only finished with a 180 stone set, and no plateau hone. I've rebuilt several 1.3s, and have never had a blowby issue.

Quick fix (that actually works!!!)... Buy a can Bon Ami Powder Cleanser (http://www.bonami.com/index.php/prod...wder_cleanser/) and slowly feed it into the running engine. You should use about 1/3 of a can. It uses feldspar and limestone as abrasives, vs volcanic quartz in other cleansers. Quartz is too aggressive, and will cause more damage. The limestone and feldspar lightly polish the cylinder by leveling the peaks and valleys, vs cutting away more material. GM, Detroit Diesel, International, and I'm sure a few other engine manufacturers have used this trick to help seat rings for 50 years.

[FestYboy]

i learn something new each day! thanks Jim!

[gauge_half_inch]

It had this issue prior to re-ring. I used a 220 grit bead hone.

[blkfordsedan]

I remember seeing my father use Bon-Ami before to help seat rings. That was a long, long time ago (early 1970's). I didn't think you could still buy it, LOL. I would do a compression check first to make sure ring seal is the issue. There may be something different about the metal content in the Mazda blocks vs. the standard American composition. It wouldn't surprise me if the Mazda iron was harder or something.

[FB71]

It had this issue prior to re-ring. I used a 220 grit bead hone.

did you bore the block? If not, did you check the bore to ensure the walls were true? If all you did was plateau hone (bead hone) with a 220 grit, chances are the cylinder wall is still distorted from previous wear. Cylinders will develop a taper at the top of the stroke, across the crank center line. If this taper is not removed by boring the cylinder oversized, the rings will never seal. This taper causes the rings to "bounce" in and out of the ring lands, in addition to the fact that the cylinder is now ovaled (as seen from the top of the bore) and a round ring cannot seal an oval bore.