4age to 7age Questions

[oldeskewltoy]

not sure what CR you want to run... but a 10.3 4A piston in a 7A(stroke is 85 vs 77) the CR is well above 11 to 1, maybe close to 12 to 1.

Quote:Check Sam's calcs, they are pretty useful!!!
http://s-86.com/s-cr-chart.html

without the math.... I don't trust the calculations... IE, my example above... with the chamber volume inaccuracies




I'd look into using either a TVIS piston(9.4 to 1), OR a later 4AGZE piston(8.9 to 1) might just be perfect when fitted to a 7A with 8mm more stroke.

I'd check a CR calculator and try to calculate which 4AG piston(77mm stroke) will work best in a 7A with 85mm stroke