Honda piston ring

Hi I am rebuilding an ST70 engine and have bought new Honda piston and rings the two top rings are different, one has a small chamfer top and bottom on the outer edge, could anyone let me know if this is the top ring or next one down, also I am looking for a good 70 head as this engine had been fitted with a 50 head ground out to fit (not well) are there different Honda heads to fit these or are they all pretty much the same, anyone got a good one they want to part with ?
Thanks Graham

the 6V is not the same as the 12V... The 6V has like a little mountain top. The 12V flat top I believe....

anyone got any ideas on the piston rings ?

Fitting rings to pistons...... the most common mistake made when fitting rings to pistons is to fit the compression rings upside down. The standard rule I learnt as an apprentice was "inner chamfer upward, outer chamfer down, unless otherwise marked." On most occasions this rule will be correct. Almost all rings that the chamfer rule can't be applied to will have a mark that goes upwards. Always read the manufacturers instructions if available.

Found this on the tinterweb.

The chamfered ring is always the top ring as far as I am aware

Higgy

I would suggest Chamfered ring will be the top ring.this is done to take into account any wear to the bore of the cylinder - ie prevent it smacking into a wear ridge at the very top of the cylinder.

Thanks Higgy
The top of the rings is marked with a letter n so you know which way up they go, I just wasn't sure which was the top ring.
Thanks very much for your help
Graham

Thanks Chief
That makes sense.
Thanks very much for your help.
Graham