Butler Performance • Pontiac Tech
326 Compression Calculator
Static compression ratio & displacement for the Pontiac 326 block. Enter your build below — results update instantly.
Static Compression Ratio
8.8 : 1
Total Displacement
326 ci
Per-Cylinder Volume Breakdown
Swept volume667.5 cc
Chamber volume72.0 cc
Deck volume0.0 cc
Gasket volume7.1 cc
Piston volume+6.0 cc
Total clearance volume85.1 cc
8-cylinder Pontiac V8. This is a static (geometric) compression ratio for build planning. cc your actual heads and confirm deck height after machining. Questions on your combo? Ask a Butler Tech ›
326 Block — Cubic Inch Reference
Bore3.754.004.21
Stock  3.719326348366
+.030  3.749331353372
+.040  3.759333355374
+.060  3.779336359378
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Dial in your compression with the right pistons, gaskets, and a matched rotating assembly.
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326 Compression Calculator

Bore: (diameter)
Stroke:
Cylinder Head Volume:
Effective Dome Volume:
Butler Ross Flat Top -8cc
Deck Clearance:
Compressed Gasket Thickness: .040 is standard thickness
Number of Cylinders:
Compression Ratio :  
Total Displacement (in.3) :  
326 Block Stroke
Bore 3.75 4.00 4.21 4.25 4.50
Stock 3.720 326 348   370  
+.030 3.750 331 353   376  
+.040 3.760 333 355   378  
+.060 3.780 337 359   382