I need rings for an HP 40 converted to 36.    Is anybody currently making custom rings?

I don't know if the engine was de-bored or de-stroked to reduce the swept volume.  But it probably doesn't matter because I doubt I could get a factory ring even if the bore is stock.

  Well, MECOA claims they are "temporarily" out-of-stock. The MECOA definition of "temporary" and "coming soon" seems to differ from the dictionary, but they at least claim they will have some at some point.

   Of course, I don't know if it is stock or not, but someone should be able to measure their stock parts and tell you what size it is.

    Brett

 p.s. many of the "40s converted to 36" conversions I have seen consists of filing off the place where it says "40" and stamping "36" in the side, counting on the fact that it isn't always checked, and that the difference is so small that they give you the benefit of the doubt on tolerances. So there's that.

This is the old Bowman caryy thru . I got some , all seemed good bar maybe ends of pinned HP 40 ring funny. Which Id do custom myself next time . Rest were ST 60 ( & dykes ) and 46 etc . No Worries .
https://rmjmachineworx.com/#27eeb94c-8135-4198-8467-5fac2bfebb32
Custom Piston Rings - Rmj Machine Worx

  Well, MECOA claims they are "temporarily" out-of-stock. The MECOA definition of "temporary" and "coming soon" seems to differ from the dictionary, but they at least claim they will have some at some point.

   Of course, I don't know if it is stock or not, but someone should be able to measure their stock parts and tell you what size it is.

    Brett

 p.s. many of the "40s converted to 36" conversions I have seen consists of filing off the place where it says "40" and stamping "36" in the side, counting on the fact that it isn't always checked, and that the difference is so small that they give you the benefit of the doubt on tolerances. So there's that.

Now I recall that I did measure the engine when I bought it.

Bore: .818"
Stroke:  .657"
Volume:  .345 cubic inches.

He probably milled some material off the button to get the compression back up.


So that's good news.  I was obviously de-stroked, so a standard ring will work.  The original owner gave be his parts stash, which included a new piston, but sadly, I found that the three "spare" rings were old ones that he had removed.

     Hi Paul and Brett:

     No I do not have any rings.  There is a Chap ln England who makes rings.  I think that he is on E Bay.  I have bought and used his rings in the past and found them to be good, inexpensive and fast service.

   There is also the guy who took over Mr. Bowman’s business.  I would give him a try!  I would suggest that you send him your p&c for fitting.  Yes, it will be more costly but I think that would be money well sent.

      Good luck,

      Frank

Hi all.

The british person Frank is refering si called Gaviscool in ebay. I´ve done some busniness with him and his ST46 rings are very good.

Kind Regards.

Manuel.