Standard Piston Markings

[TimD]

I'm finally getting around to putting my engine back together, when inspecting the pistons I've noticed they all have a B stamped on them.

But, 3 have the number 1 stamped, and one has a number 2.

Any ideas what they mean?

[TimD]

Answered my own question.

The block is also stamped with corresponding numbers, in my case:

Cyl 1: 2

Cyl 2: 1

Cyl 3: 1

Cyl 4: 1

[gorganl2000]

pistons come in 3 sizes stock....

so the builder/you basically know what to order when you need to replace---assuming everything is within original tolerances and the builder is using standard pistons

as you've seen,,,its also stamped on the block by each cylinder

[Socks]

Bore diameters:
STD mark 1 = 74.000-74.010mm
STD mark 2 = 74.010mm-74.020mm
STD mark 3 = 74.020mm-74.030mm
Limit before rebore = 74.23mm

Piston diameter:
STD mark 1 = 73.900-73.910mm
STD mark 2 = 73.910mm-73.020mm
STD mark 3 = 73.920mm-73.930mm