I guess its time-

BenK wrote:

Not a diesel guy, but continue to read up on it and all of these threads confirms
my choice to pass on diesel. Of course just for me

Now know that the higher BAR/PSI is for finer fuel droplet spray. IIRC CP3 is
in the neighborhood of 1,500 PSI and CP4 around 2,900 PSI. Initially didn't think
much of the 200 BAR number...till looked up the conversion to PSI, of which
am more knowledgeable. That is a 14.5 factor (1 bar = 14.5 PSI)

Both have the dumb designed crank/cam to connecting rod not connected to the
piston bottom.

Made worse using diesel as the crank lube.

Ben, just correcting some of your info here. The CP3 is more known for having a nominal pressure of 24,000 psi. Service manuals have it dumping up to just over 26,000 psi of pressure in the rails and some aftermarket companies can get the pressure higher. Where as the CP4 pump is used in systems that dump anywhere between 29,000 psi and 32,000 psi into the rails. The deal is that the cp3 will not send shrapnel through the injectors where as the cp4 will. Check out the fluid circuits for both pumps (both can be found online easily). You'll find that the cp3 has a dedicated lubrication circuit that goes back to the tank while the cp4 runs diesel through the crank/cam lobe area, then into the compression chambers to feed the rail. Also, CP3 doesn't have rollers, its more like a solid tappet style lifter similar to the lifters used on a Cummins ISB motor. One of the issues with the CP4 as I understand it is that the lifters have a roller on the bottom but there's no mechanism that prevents the lifters from spinning in the bore. I believe the lifters rely purely on the cam lobe bumping the roller to keep it oriented properly.

The numbers you originally quoted are more for direct-injected gasoline motors.