Cummins Diesel Twin 500hp QSC8.3 Permanent Slow Speed

[RaySea Lady]

You may want to check with cummins directly with your engine serial numbers.

I have twin 2001, 450hp turbo cummins on my 58 Bluewater, and when I asked cummins a few years ago about running at low rpm, they checked my serial numbers and told me there was no problem as my engines were equiped with a unit (forget what it's called) that would simply not allow the thermostat to open until the oil had reached its required temperature to insure best lubrication. Consequently, my diesels, once warmed up, run at around 175 pretty consistently at 1100 or 2200 rpm's