Larry E. Snyder writes:
>I've checked the bores on my Spit, and there are slight ridges at the top
>of the piston travel. When I put new rings on my bad piston, are they doomed
>to break?
>
The rule of thumb I was told is that if your fingernail will catch the
ridge, the ring can break. Apparently you can often get away with it if
the ridge is smooth.
>The Bentley manual says I should hone the ridges off. Is this difficult?
Not with the right tool(s).
>How do I do that?
With a ridge cutter, a special tool that can be bought at an automotive
specialty shop. After removing the ridge, you will need to put a
crosshatch finish on the bore. I used a special hone that looked like a
toilet bowl cleaner with little abrasive balls on the ends of the bristles.
>The Haynes manual says to "step" the piston ring. What does that mean?
Stepped rings have a bevel at the part of the ring that would collide with
the ridge. Apparently, they were available when the cars were new so that
dealers could do "quickie" ring jobs without worrying about ridges or
finishes. From what I could find out, they aren't available any longer.
> It says that the new ring will break when it hits the ridge. I
>really don't want that to happen - so what do I do?
>
Cut the ridge and hone the bore; it isn't hard if you go real slow and
exactly follow the instructions that come with the tool. The key is that
you have to take out the pistons and make _absolutely_sure_ that you don't
get any metal particles into any oil passages or onto the crank bearing
surface.
It almost seems easier to just take it to a machine shop :-(
>Thanks much,
>
>Larry
>lesnyd@monsanto.com
mike.
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