Thanks, it indeed looks like it's bored to mil. standards. So the military used another piston with a smaller diameter, Gandini offers a piston on there side of 69.00mm but with another top without valve recesses. It might be this piston they used.
I used a 3D optical measuring machine (Werth) with an accuricy of 0.0003mm (L50) but for this a bit over the top
Gandini piston
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Re: Gandini piston
According to their catalogue the Hepolite piston for standard compression ratio (6.3 : 1) for the years 1948 to 1955 had a cone top without valve pockets. The high compression piston (7.5 : 1) for the same years had a domed top with valve cut-outs.
See page 32 here:
http://archives.jampot.dk/technical/Pis ... 4-1963.pdf
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Re: Gandini piston
Thanks, it makes a lot clear to me, we'll use the Gandini piston and set the bore diameter to 69.1-69.12 mm.
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Re: Gandini piston
You may like to know that T&L Engineering always bore to plus five thou on Gandini pistons
hope this is usefull
Tony
hope this is usefull
Tony
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Re: Gandini piston
Thanks Tony, I will hone it to 69.013mm (+0.12mm/4.7thou")