On Sat, 8 Mar 2003, Royce Woodbury wrote:
> So I did what I thought was a reasonable
> thing. I bought a brand new 7/16" reamer (import, I think) and ran it
> thru the bore. On inspection, I was horrified to see a helical score in
> the bore, a result of a burr or something on the reamer.
>
Well, not to be mean-spirited, but you do get what you pay for. I never
buy anything but good, solid Cleveland Twist Drill reamers from the local
industrial supplier. Cheap tools are entirely too expensive to fool with.
> I tried to
> "hone" out the bore with a dowel and 320 grit wet or dry sandpaper.
> Very slow progress as the sandpaper loaded up on the bronze cylinder
> material quickly.
>
Which is why you needed to keep it fed with a steady stream of oil:)
> So I gave up and put the engine together anyway. On
> running on air, it appeared that the oil was turning black. I assumed
> that this was the Oring wearing away on the "rough" cylinder bore.
>
Also, metal wearing in against bronze will tend to produce blackened oil
too.
> So my question is : is this too large a bore for a 7/16 O ring (.4375
> nominal) ?
>
I think you can get away with it, that's about five or six thou.
---
Paul Anderson
geeky1!paul
"Nature has been kinder to us than we had any right to expect.
--- Freeman Dyson
