OxTheGreat

Im new to LS engines amd am planning a build very soon. But nothing is adding up. Where am i getting my math wrong on engine compression.
5.3L LM7 with 862 stock heads
Bore: 3.78
Stroke: 3.62
Cylinders: 8
Pistion cc: 2cc
Head cc: 61cc
Head gasket: .040
Pistion Height: .007

Everything is telling me crazy **** like 10.7:1 when known ratio is 9.5:1

OxTheGreat

After doing some tinkering on here and plugging away at numbers i suppose my pistons are the 9cc dishes rather than the 2cc flat tops.

JoeNova

Stock engine?

You would have dished pistons, and a .051" headgasket most likely.

OxTheGreat

Yes, 100% stock, im mapping out a JY build like many.

murphinator

iTrader: (2)

flat top 4.8/5.3 stamped blocks are 4.8's so you should have the dished.