Custom Piston Rings - RJM Machine Worx
 

Years ago, Frank Bowman was the provider of a wide variety of piston rings for our engines.
In 2017 he sold his business to Bjorn Baal.
For a while, Bjorn did business by email only. I reached out to him just yesterday and he passed a link to his new website which is a huge improvement to his accessibility!

https://rmjmachineworx.com/

I'm rebuilding a Super Tigre 90 and Bjorn's response to questions was nearly instantaneous - literally within just a couple of hours!

I've used his rings in ths past with success, and I'm confident that my newly ordered Super Tigre rings will work great.

I bet they will work great.

They do work great! Just got a ring for my Fox 50. It's perfect. Took about ten days, they said there was one week lead time. Well worth waiting for. It's awesome to have someone still provide a service like this for our hobby.

new ring for supertiger .75
 

Just received my new ring for a Supertiger. This was fast, less than a week. fit perfect.

Bjorn just sent me a YS-120 ring. It arrived in 3 days and also was a perfect fit.

Making piston rings takes skill. Making fine piston rings is an art form.

I have not used any of Bjorn’s rings yet, but I will be. I have an ST G60 Blue Head and about HP .40 that need rings. I’ll be using Bjorn without hesitation. OEM rings work fine, but they often take longer to break in. I like the quicker break-in of Frank/Bjorn’s Meehanite and the narrower ring gap makes for a better seal.

I still have about a dozen of Frank’s rings hanging on my parts wall. I am a hoarder - I ordered spare rings for every ringed engine I owned (at the time) awhile back. :D. I’ve only needed to use a few of them so far.