once I had disassembled,cleaned rods and caps found 3 caps I cant make out #s stamped on them .Whats my best next move? Any help? Rick

I assume you have tried a magnifying glass, correct?

If they were steel-stamped, and the stamped area didn't suffer mechanical damage that obliterated or mangled them, the markings are likely still there, in the metal, beneath the visible surface.

Example: Sometimes, criminals/thieves grind serial numbers off firearms, etc, but the markings can be raised by etching the surface with strong acids.

Here is a post on how to go about it below. They are using the technique to read a worn tag on an antique engine, but it also works for situations such as yours:

Raising Serial Numbers From Metal

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Ron Haskell

Default Re: Serial number help: Raising tag numbers
Here is something I saved from an old E mail regarding finding marks on an old boiler. I hope it helps.

First sand the surface to be etched, until it is more-or-less even, with only superficial pockmarks from the corrosion remaining. Try to remove as little metal as possible.

Then etch with one of the following reagents:

1. Hydrochloric acid (one part concentrated HCl, one part water). Apply boiling hot. Might not develop well, due to too low temperature (actually, for best results, you should boil the part to be etched in the acid, which is a bit difficult here ......)

2. Ammonium persulphate (one part by weight of the salt to nine parts of water). Vigorously rub the surface with a cotton saturated with the solution. Apply at room temperature.

3. Nital (one part concentrated nitric acid, five parts ethyl alcohol). Brush on at room temperature.

There are other, more complex reagents that can be tried if these fail. Come back for more information to alex.den.ouden@consunet.nl .

The punch (steel stamped) marks do show up on etching, even when they are no longer visible on the surface, due to the plastic deformation caused when the punch(stamp) is driven into the surface.

I expect that the letter-and-number-punches will show up better than the larger cloverleaf stamp. The deformation with small punches usually is a bit deeper.

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Beyond that, you could take the rods/caps to a machine shop and ask their advice on re-matching or failing that, how to machine/correct.

Here is another quote from that SmokStak Post:

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One idea is to wire brush the end of the crank (or wherever the number is) and wipe it with muriatic (read "Swimming-Pool") acid. Let it set and inspect in bright light.

Since the metal is compressed where the numbers are stamped, the acid reacts a little differently there than on the rest of the metal. IT WORKED FOR ME!

The FBI has ways to get serial numbers off of guns when the numbers are ground off, but unless you involve your engine in some sort of crime, they're probably not interested.

Kevin

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Put the caps on the rods and see if you feel an edge at the parting seam of the rod. If the surface is smooth all around and you can feel no unevenness at the parting line you should be alright. Just for insurance take an inside mic and check the diameter. Or have rehoned.

I think I'll visit my machine shop monday. Thanks for the help. Rick