+40 oversize rings identification

Previously wrote:

some time ago i bought a set of +40 oversize rings from RGM as spares since my bike is running this size. the problem i have is i am nearing the end of a complete rebuild after carrying out a crankcase breather mod amongst other things which i will be writing about later., anyway when i opend the packet there is no clear identification for the chromed compression ring. both sets of compression and scraper rings are ash black and marked

/E TOP+0.40". Is it possible they have sent me two sets of top rings. any input on this would be greatly appreciated as i cant contact RGM till tuesday. many thanks sam

Sam,

The word top does not indicate a top ring,it means that top surface of the ring faces upwards.It is quite common for the two upper rings to be the same. The bottom ring is the oil scraper ring and usually slotted.

Regards Ron

Just to confirm what Ron has told you. You must have two "taper rings" Quite often this is the 2nd ring down when the top ring is chrome. just Fit with the words "TOP" facing skywards or upwards. However as you are suggesting, it is or was common to have the top compression ring as a plain chrome ring and this is what Hepolite always did. I know what you must be feeling, a little unsure, and I would be too!

A taper ring acts like a halfway house between a compression ring and an oil scraper ring and the top ring is the one that does the hard work of gas sealing and takes the wear punishment and the heat which is why it is usually a chromed ring. Have you tried the maufacturers web site?

Once you know what is what, don't forget the 120 degree ring gap spacing when installing the pistons into the bore.

Les