Polly those hankooks are fantastic. A vastly underrated road/track compromise tyre, better than an 888 imho as it won't leave you in a ditch if the surface gets wet. I don't have experience with the 595 rs-r personally yet. Considering the price difference I think it's a no brainer.
btw don't you think the sample size in that comparison chart is too small to read anything into it?
does it smoke on startup paul ?
i re-shaped mine paul (they,re steel/workable eh, unlike the cast compression rings) its this current engine actually.
the oil rings were totally gummed into the pistons originally, so i cleaned and stretched them, but i had slightly miss-shaped them while stretching and they had the daylight patches.
the 1st corsa piston engine had a similar problem problem (i had it underbored eh) and the arc of the ring miss matched the arc of the bore, and that one smoked horrendous !.
iirc yours were oversize rings that were gapped eh, maybe the same problem ?
i spent about 1 hour tweaking these ones till i could,nt see daylight, and it cured it
no the corsa pistons are 72.5mm paul, but mine were well worn so i asked him to underbore it by 15" thou so i could regap the rings the smaller 72.2mm ish (and i honed the pistons down to a nice snug fit)with the bore machined to a smaller tighter dia which brought the ring end gaps back to min specs, maybe the oil rings are mis-shaped. it leaks the same amount across all 4 cylinders.
how do you bend n shape the oil rings without affecting the end gaps?
wanna try the easier cheaper valve steam seal replacement first
wishfull thinking paulthinking back in Jan, when i was reinstalling the valves back into the head, i think the inlet valves popped through the stem seals easier than the exhaust valves so maybe they were worn?
This is why i stick to stock pistons, if you have the patience to repair this then all credit to you polly! How much boost you planning to run anyway on the forged setup and what hp would you be happy at?