SouthTexan
Senior Member
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- Jan 24, 2015
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Yes, but most marine engines turn faster than their on highway counterparts. And the governed limits of the Cummins engines over here have more to due with emissions certifications which are tougher here in the US. Since Cummins does not know what type of vehicle the engine will go in or what type of intake/emissions system will be on the vehicle, they have to do an engine dyno emissions certification instead of a chassis dyno emissions certification.
The fact is that due to its longer stroke ratio, it will never make the horsepower the Cummins will make reliably. Not only that, but it has a narrower torque curve than the Cummins (again due to its bore/stroke ratio) making the engine loose a lot of its torque by the time it reaches peak horsepower. This is a characteristic of an under square engine. The Cummins on the other hand has a much flatter curve retain a lot of it torque through out its power-band and having a higher safe reliable rev limit to create more horsepower.
The fact is that due to its longer stroke ratio, it will never make the horsepower the Cummins will make reliably. Not only that, but it has a narrower torque curve than the Cummins (again due to its bore/stroke ratio) making the engine loose a lot of its torque by the time it reaches peak horsepower. This is a characteristic of an under square engine. The Cummins on the other hand has a much flatter curve retain a lot of it torque through out its power-band and having a higher safe reliable rev limit to create more horsepower.
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