Re: Dang Dirt!

[Pete]

What is great compression? Should be about 120 psi in both cylinders with throttle open and cold. If you pull the pistons and the block has no or nil scratches and mics ‘OK’ (acceptable out of round and taper) just hone it and new standard rings, check end gap. I would hold on +15 pistons unless the cylinders really mic bad. Post numbers of bore out of round and taper. If cylinder mics ‘OK’ to glaze bust I use a 240 grit silicone carbide ball hone at 400 rpm and 1 stroke per second and about 20 strokes should do it, with lots of oil, gives a correct angle (about 45degree from up to down stroke) cross hatch and does not get hug up in ports. Metal removal is small with ball hone at less than 0.0003". Works well in blind bores if you get the right ball hone. I use Brush Research ball hone of correct size for the bore and buy them thru Summit Auto parts, they had best price when I purchased.

If you decide to bore +15 you will need to get rid if the created sharp edge at all the ports (bad for new rings). I do this with 180 grit wet paper with finger rotation on each port( patience here) some do with a fine file from the out side in (covers removed) then ball hone as noted above. Regardless of just honing or bore and hone thoroughly wash with hot water and dish soap several times (I use a round toilet bristle brush to scrub) until bore wipes absolutely clean with white cloth or paper napkin. Then blow dry and "quickly" oil up with outboard oil to stop rust and bag until ready to assemble. Do not use WD40, mineral spirits, gasoline, or any other stuff etc. just hot water and soap and outboard oil.