Piston identification

[DerekElliott]

Here is a piston that I have taken from my spare engine it looks like it has been modified its a Alcan piston and a bit heavier than the one in my main engine has it been filed or what???
Has anyone seen this before

Regards derek

[bh.sprint]

Hello Derek,

The piston looks as though it has been filed to alter the inlet timing. Some tuners alter the piston rather than file away the inlet port in the spigot and crankcase. The top also looks as though it has been lowered to line up with a larger transfer port. The pistons do vary in weight quite a lot. Some of the Arrow/Leaders owners weighed some last year and came up with a range of weights. Some may be due to the variations in size ie. +20 etc and some variation in design/length or even different types of alloy.

Others may have some more ideas, Regards Brian.H.