Piston grade

[shocky]

we were discussing this at the weekend, a mate was looking into mitaka 70mm pistons.
he was told, by supertune, that A ~ 69.97mm; B ~ 69.98mm; C ~ 69.99mm

Agree, had the same figures for the non avanti pistons. Other kits may be different and will be matched to the bore to get the right tolerance. If in doubt get it measured by someone who knows how to work bore gauges.

Original SIL barrels for example are often graded -, 0, + and pistons available to match. Once they've been rebored though all bets are off.

Does all bets are of mean up and down the bore a few more times with a three legged draper honer for good measure

[rosscla]

Just that you're at the mercy of whoever does the rebore what clearance you get

[shocky]

Just that you're at the mercy of whoever does the rebore what clearance you get

Despite trying my recent hone and new piston hasnt seized sold dispite redlining it in the first 3 gears and uphill using mineral oil which is more than can be said for the rapido that was "checked" by the supplier so I guess this tuner knows what he's doing with a good old indian barrel and meteor piston ( evidently there good these days)