club kh pistons / rings

[robin rose]

The compression rings on my new set of club supplied kh pistons are different in that one of them is manufactured parallel and the other
has a rebate /step against the contact face of the cylinder wall reduceing the contact area. My question is which position do they go and which way up?
Im guessing with step down and manufactures printed dimensions up at the lower position. Also the ring gap seems a bit excessive at .018 in a new bore which is admittedly at the top of the tolerance range. Rob

[john.whiting]

A stepped ring was sometimes included in ringsets in case the rings were used in a worn bore.......the step goes top groove facing up,and avoids ring being broken by any lip in the bore........just my 2d worth,not gospel.

[Simon.Gardiner]

Step on outside of ring, fit step on underside (instructions on BMW R100 rings).
(Step on inside of ring, fit step upwards - AE rings for Rover V8)
To be 100% sure phone/email the makers, if it's IMD they'll be happy advise!

HTH

SG