First to turn 5000 plus RPM’s , and make power there , and yes there is power there, I will lay out the my list of parts I think absolutely necessary
This combination of parts will make peak power at or above 5000 rpm’s and turn to 6000+
A maximum effort thoughfully Ported head with a good intake manifold to distribute the intake air evenly .
Second a good cam program , with a good valve spring that matches the cam profiles
A properly clearance engine , that is easily said, but few people know what that intales ..
First you have to line hone the main bores to make sure they are straight, and of the right bearing crush clearance .
Deck the block, to be parallel with the mains , you would be shocked if you knew how far these things are all over the map.
Bore the block with a torque plate , and hone the proper piston to bore clearance
The Cumming block is actually lighter then a big block Chevy Dart block, and very flimsily, the bores are susceptible to moving all over the place with the head bolted on, and now with you big studs , and killer pistons , along with o rinds or fire rings that hold everything together tight, the rings are still round , but the bores are not .
Ring package , this is one of the secrets that cost very little , but make a huge difference in rpm potential. As much as 75 hp is locked up in a ring package that was designed to run half a million miles
Now , the secret to all of this is............
besides the head, the rest is fairly inexpensive , and part of any good rebuild.
The higher you rev a 5.9 Cummins the less cylinder pressure and subsequently torque needed to make big hp , and the less you will spit head gaskets out .
One other factor is that with higher flowing heads , better cam profiles , and higher rpm’s the fuel requirements will actually be some what less , in that the engine will become more efficient in regards to BSFC
The turbo will need to be a lot bigger , and designed in my opinion with a lower pressure ratio, meaning less boost , more air
Been on the dyno with a Cummins like this and peak power was around 5000
Also the RPM’s of the water pump , has zero to do with all the freeze plugs blowing out , its called micro steam pockets at the top of the cylinder bores , they form when the water is forced away from the hot spots by steam bubbles , when the water rushes back to meat the then hotter bores the rapid expansion of the steam explosion is the cause of this problem.
