So as I am in cleaning and building mode now -- I am searching for rings -- 90mm diameter but the thickness I'm not sure on yet.
These have very tight clearances (almost zero) to the piston grooves.

Do we have any ideas on where these may be available.?

 

https://www.ebay.co.uk/itm/225689130941 ?

note: I did not check in details if these are actually correct of not


or maybe these guys

https://www.enginerebuilding.eu/jagu...jr-aj16sc.html

could have them available , would not cost anything to ask?

 

Yes. Thank you. This gives me hope to press on!

 

Wish I had seen this post before

The eBay ones will not work for the X300. The dimensions don't match nor does the ring design

 

Try this.

https://www.totalseal.com/find-a-ring

 

I contacted these guys out of curiosity. They will sell you the correct-sized ones but they don't do the Napier-style cut on the second ring. They say that the profile of their second ring will give the same performance as the original ring. I already have a set from Grant piston rings so I didn't order any but nice to know that this is another option as well

 

Note: these would be moly coated. whereas the Grant ones are phosphate coated. I believe moly coated rings require more cylinder prep

 

Shop High Performance Piston Rings Online - Deves.com

Call these guys with the dimensions. They were the old suppliers of piston rings to Moss Motors. The set they sell will work. Albeit the ring profiles will not match

If you want the original ring profiles, order the second ring from them. And the first and the oil control ring from Grant piston rings

Both in cast iron (although Grant will do chrome coated ones like the original)