hepolite rings

What bike? ,earlier ones have different requirements, what rings do you have?.

Sounds a bit unusual, you will need to measure the ring grooves to check these have not been machined to fit the rings in the past. I can't give you the sizes ,but someone else may be able to. +20 ring sets do appear on E-Bay .

Would they by any chance be a set of Cords rings? The description seems to fit.

don't know if this will help in some way

http://www.fwthornton.co.uk/8.html

I was thinking cord rings too!

I think the lads are right ,Cords rings. They won't like being swapped around if used. They had a reputation for faster bore wear than std type rings, Its possible they may work if re-used ,on balance I would give them at try , although the fitting insructions say don't mix them up, but then I always have been a chancer.

The reputation for rapid bore wear put me off Cords rings. They seem to be a short-term work-around for bore wear and high oil consumption. I have a set somewhere, never fitted. I just got ordinary ones instead.

Its a slim possibility that normal rings may still work, spend some time checking piston/bore clearance and piston ring/piston clearance. But if the pistons are the slotted type ,best scrap them.

Hepolite 1977 catalogue.

1948/66 500cc OHV model 7/88/88SS.

Original Norton piston and Hepolite 10338 piston.

Top compression ring 1/16 inch width. Max radial thickness 0.105 inch. Ref number MP 6201.

2nd ring sizes as top ring but ring numbe is MPT 16017. Tapered???

Oil control ring 5/32 thick. 0.096 inch max radial thickness. Ring number MEDO 9222

Hepolite ring set number R3730.

If some clever soul has played with the piston or they are made cheaply in India or Tiawan or Italy the very best of luck in finding correct rings.

Radial depth is important especially for the compresion rings as the gap between the back of the ring and piston has to be correct if the ring is to seal the bore correctly and it requires the gasses behind the ring to do this. If the gap is too large or too small........ Unfortunately in my young days 'some' dealers flogged rings of the correct bore size and thickness only with no thought as to radial depth or even ring material etc. Of course it could be they knew nothing about the subject...or the customer??