Thanks for the replies folks. Nev I see what you mean about the valve cut outs, I'll assemble & check carefully, have access to a mill anyway so no problem.Crank is apart for new big end so will be rebalanced to suit new piston as necessary. On the piston to bore clearance, I think 0.007"/0...

Nev It is a solid skirt, so was going for a generous clearance.Draganfly suggest 0.005"-0.007", I was thinking in the region of 0.008"-0.010". If you could weigh a Hepolite to give me an idea how the Gandini might affect balance that would be useful, also could you post a pic of ...

Gandini piston details: VH500 1950/51, std piston 81.8mm, 7.5:1 comp. Weight inc pin & clips = 485g. Expansion @ 250deg = 0.012" / 0.29mm (bottom of skirt, 90deg to pin). My old piston was Hepolite +0.040", but I stripped the engine down 20 yrs ago and lost it somewhere along the line!...

Hi Robin
The piston in question is a std 81.8mm 7.5:1 comp ratio for my '50/'51 VH500, I'm about to have the cylinder relined & was looking to get some more specific info on clearances for the machine shop to work to. I'll weigh it & measure the hot expansion.

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Evening all.
My new piston arrived yesterday from Draganfly, it's a Gandini job, made in Italy.
I was expecting one of the JP ones, but the Gandini one looks fine.
Having read that the JP ones are relatively heavy with a heavy pin, does anyone have any experience of Gandini ?