carbide cylinder bore conversion (Bore Tech)

[Greg Hermann]

>In a message dated 1/11/99 3:39:54 PM Pacific Standard Time, bearbvd at sni.net
>writes:
>
><< Yeah--as always, some luck will be needed. Your use of the words "solid
> lap" got me to thinking some more--mebbe the liner should be finished to
> the same bore as the polished bores in the block, but with a cross-hatch
> pattern from maybe #80 or #120 stones, and then be given the carbide
> treatment. The thought is that maybe this approach would give the lapping
> compound somewhere to "hide" and something to work against. What do you
> think??
>
> If Enco is Sears, does that make MSC = J C Penney's?? :-)
>
> Regards, Greg
>
>  >>
>On the solid laps they often cut a small spiral groove to carry the lapping
>compound and let the swarf (removed material) float out of the way. Honing to
>size would be best, be careful about how coarse a finish you leave. The peaks
>will wear away and the lap will go oversize very quickly. Might try a small
>spiral grove in the bore. Interestingly, when they lap Granite surface plates,
>they use a cast iron plate, and charge (the term for applying lapping compound
>to a lap) the lap with dry diamond powder by crushing it into the cast iron
>with a hardened steel roller and then working the high spots down like block
>sanding. Might work well as it would keep the lap from dying as quickly. You
>could charge the lap with a rod and a radiused race bearing by rotating it in
>a lathe.
>As for MSC, it is more like Neiman Marcus in comparison.
>Fred

Aha!! Maybe hone the liner/lap with a coarse set of stones, and then polish
it to final size, but leaving some of the deeper grooves showing!! Thus,
lots of smooth surface at finish size, and slower wear to oversize, but
plenty of grooves to "charge" with the lapping compound.

If memory serves, a pitch lap and rouge are what is used on glass for final
figuring and polishing of optical lenses and mirrors. Also know a fellow
who has been known to use toothpaste to lap gears from a motorcycle tranny
to each other.

Thanks!!

Regards, Greg