Not trying to come off as too troll-ish, but I didn't see anyone mention any of the old Ferrari 4 cylinders.
Tipo 107 was a 2L, NA 4 banger making 125 HP per Liter in the 1950's.
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I actually am a fan of the torque curve of the F20C engine. It is literally flat line with a step where the VTEC came on. So cool.
