CPL is Critical Parts list.
fuel pump, injectors, pistons, etc.
Marine motors are over-fueled and have a fair amount different than the other off-road applications. More than just the manifolds.
I re-CPL'd a QSK60 G-drive this afternoon for 2,700hp, it had to be recertified for Tier 2 emissions with the ECU and injector update. Cummins INSITE refers to the CPL as Control Parts List when you make a CPL change and get approval from Cummins. Critical Parts List is also used interchangeably.
On a 903, the fuel rate is controlled by the button in the PT pump. I can bump an old NTC350 to 475hp by putting a shutoff valve in the fuel return. It won't last long, on the NT-series you'll have stretched headbolts and be cutting liner counterbores and shimming liners because it'll stretch the block out of shape if you do it for very long. But all you have to do is increase the rail pressure on Type G or AFC PT pumps for fuel rate so when the injector follower comes off base circle and opens the metering port it forces more fuel thru the hole.
There is no difference in internal engine parts from a marine VT903 to one used in a truck or other off-road equipment. Only difference is the pump and governor settings running them up to 3,600 rpm in marine. The only reason they can run higher fuel rates and rpm on marine engines is because they have a better cooling system than air-to-water radiators in non-marine applications. And they figure the average marine engine only gets about 100 hrs a year on it, so if it lasts 2,000 hrs that's a lifetime for most yacht owners. But that won't make any difference in getting overhaul parts.
