Butler Performance • Pontiac Tech
428 Compression Calculator
Static compression ratio & displacement for the Pontiac 428 block. Enter your build below — results update instantly.
Static Compression Ratio
11.1 : 1
Total Displacement
427 ci
Per-Cylinder Volume Breakdown
Swept volume873.9 cc
Chamber volume72.0 cc
Deck volume0.0 cc
Gasket volume8.7 cc
Piston volume+6.0 cc
Total clearance volume86.7 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 ›
428 Block — Cubic Inch Reference
| Bore | 4.00 | 4.21 | 4.25 | 4.50 |
|---|---|---|---|---|
| Stock 4.120 | 427 | 449 | 453 | 480 |
| +.030 4.150 | 433 | 456 | 460 | 487 |
| +.040 4.160 | 435 | 458 | 462 | 489 |
| +.060 4.180 | 439 | 462 | 467 | 494 |
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Dial in your compression with the right pistons, gaskets, and a matched rotating assembly.
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428 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) : | |
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| 428 Block | Stroke | |||||
| Bore | 3.75 | 4.00 | 4.21 | 4.25 | 4.50 | |
| Stock | 4.120 | 427 | 449 | 453 | 480 | |
| +.030 | 4.150 | 433 | 456 | 460 | 487 | |
| +.035 | 4.155 | 434 | 457 | 461 | 488 | |
| +.040 | 4.160 | 435 | 458 | 462 | 489 | |
| +.060 | 4.180 | 439 | 462 | 467 | 494 | |
| +.065 | 4.185 | 440 | 463 | 468 | 495 | |