This page is full of conflicting piston info . lol
What is the O.D. of the pistons ?
So I did some math ..
1.2 x 8 hole =9.03mm³
1.1x 10 hole =9.49mm³
1.3 x 8 holes =10.61mm³
1.2 x 10 holes =11.30mm³
The formula is πr² (3.14 x [1/2 of hole x 1/2 of hole ]x # of holes
1.2 mm with 10 holes ::
3.14 x [ .6 x .6] x 10 holes =
3.14 x .36 x 10=
3.14 x .36 x 10 = 11.30
Hope this helps
This will only apply to strait hole pistons
The angles hole pistons when moving slow will act just like (or close enough) to a strait drilled piston but wonce speed of compression increases it will block some of the hole , kind of like crimping a water hose .
Hope it helps