Mazda 12A Specs
Mazda 12A engine specs: 70 ci (1.146L), 2-cylinder, 3.5433" bore x 3.1496" stroke, 9.4:1 compression.
Dimensions
| Displacement | 70 ci / 1.146 L |
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| Bore | 3.5433" |
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| Stroke | 3.1496" |
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| Cylinders | 2 |
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| Compression ratio | 9.4:1 |
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| Bore/stroke ratio | 1.125 |
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Construction
| Block material | aluminum |
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| Head material | aluminum |
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| Valvetrain | Rotary |
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| Fuel type | gas |
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| Advertised HP | 100 hp |
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What these numbers mean
| Bore/stroke character | 1.125 — oversquare — bore exceeds stroke, which favours higher RPM and larger valves |
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| Mean piston speed at 6,000 RPM | 3,150 ft/min — conservative for a street engine |
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| Displacement per cylinder | 35.0 ci |
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| Static compression | 9.4:1 — low by modern standards, generally happy on regular pump fuel |
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Vehicles (3)
- Mazda RX-2
- Mazda RX-3
- Mazda RX-7 (SA22C)
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