On Jan 24, 2:43*pm, "mark" wrote:
I have a new cummins 6bt 5.9 210hp and I regret not getting the 260 or
315hp versions. Is it feasible to upgrade the 210 to a 260 or 315.
Other than an after cooler what else is different? Would it be easier,
cheaper just to replace the engine.

I would check directly with Cummins, and one of the first questions I
would ask would be, "What happens to my warranty on this engine if I
add an aftercooler, increase fuel delivery (probably), change the cam
(maybe), and make all of the other modifications required to get an
additional 50-100 HP out of this same block?" I suspect the answer
won't be one that pleases you very much. Maybe if you hire Cummins
factory certified people to make the upgrades you would be OK, but if
it were me I'd want something in writing from Cummins in order to
protect my engine warranty.

Is there any chance you actually have adequate HP but aren't using it
effectively? How's your prop? Is there a chance that changing your
gearbox could tweak performance to a satisfactory level?