I change my answer, get a shop to do it for 60 bucks and skip pizza night for 2 weeks.
I recant all previous statements
I recant all previous statements
Boring over .080 , questions
- Thread starter dustin lafeir
- Start date
Here's how I do it. Blaster pistons start at 66mm and move up in size in increments of .25mm all the way up to 68.25mm. Most cylinders will clean up in .5mm. The most wear will be around the exhaust and intake ports. Bore the cylinder to the smallest available piston size - .001" until it cleans up. We've done this on a lathe with a face plate, Bridgeport milling machine, Bore Master and Kwick Way boring bar. The machine doesn't matter as long as the cut is perpendicular to the cylinder base, on center, and isn't full of chatter marks after the bore. The next step is to chamfer the ports, top and base of the bore.. I use a diamond bit to get the dimension I want, then a small 220 grit sanding drum to finish them off. The next step is to hone the cylinder. I'm only going to say this once........no matter what finish you get with your cutting tool, you need to hone the cylinder with a positive pressure hone. A three stone, spring loaded hone isn't going to work. If Dad works in a shop, tell him to use a pin hone if they have a big enough arbor. Take a micrometer and measure your new piston skirt @ 90 degrees to the pin, about 3/4 of an inch above the bottom of the skirt. Pistons aren't straight or round. You're looking for the largest part of the skirt. Wiseco pistons specify .002" of minimum skirt clearance for forged Blaster pistons. Add .002" to the skirt dimension. This is the final bore dimension after the hone. Set up a bore gage and hone the last .003 from the cylinder walls. If you've never done this before, good luck. When you're done, you should have no out of round and very little, if any taper.
