In a previous post I asked for advice about a rebore, have now accurately measured everything and the standard bore has a maximum of .003" wear at the top of the bore so manual says rebore needed if wear in exccess of .005"also checked piston clearance in the bores top middle and in unworn part of the bore at bottom. .008" clearance at top .007" in the middle and .005" clearance in the bottom unworn part of the bore. I have bought a new set of standard piston rings because the old ones have to much clearance in the grooves manual says .001-.003 " mine has .006" clearance. I bought what I thought were Hepworth rings but they are in an imatation Hepworth box, the clearance in the grooves is spot on but when I try the rings in the bore I am getting a ring gap of 018 " at the top .017 in the middle and in the unworn part of the bore .015" The manual says -008" to .013" gap. Have read elsewhere that these new type Hepworth rings are not to be trusted they seemingly do not run in very well in fact if you by the new type Hepworth pistons you are advised that the pistons are OK but you should change to better quality rings. Would like your thoughts on this please.
A few years ago I had a rebore on my A10. New hepolite (deliberate small h) pistons and rings were supplied. Cheap enough.
BUT after over 1000 miles the rings had not bedded in engine still oily. Pistons were fine but the rings absolute junk.
Had another barrel linered and bored by SRM who also supplied GPM pistons. I fitted new old stock Brico rings, which bedded in in about 200 miles.
Would I buy new hepolite rings - never again. Some suppliers of new hepolite pistons actually remove the rings supplied and break them and fit Italian rings.
New old stock for me.
Thanks for that reply Julian I will look for alternative rings.
Worn bores usually best honed to allow new rings to bed in.