Engine size

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10-05-2011, 03:28 PM

Shalamara

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Engine size

Why did GM build 3 motors so close together in size? 302ci, 305ci, and the 307ci

10-05-2011, 07:04 PM

z28pete

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The engines are similar in displacement, but the internal dimensions are entirely different.
302 4" bore X 3" stroke (Free breathing high revver)
305 3.74" bore X 3.48" stroke (Built to meet pollution control)
307 3.87" bore X 3.25" stroke ( No good reason for it)