The stock DCEC Cummins 6BT5.9 P-pump engine starting at 210HP 750NM 2500RPM is an excellent starting point for performance upgrades, we have released the 300hp 1000Nm governed to 3500rpm, this is very good for family use you do not need to worry too much about the cost and durability, we also offer 12 months warranty for it.
If you are looking for a good strong reliable workhorse engine set at around the 450hp to 650hp with up to 1300nm to 1700nm of torque, the following is a brief outline of what will be required to give you plenty of power to tow the heaviest trailer up any mountain, while keeping cool on the hottest day. These are just suggestions as we at Cummins Performance take no responsibility for any damage to your engine also any changes to the RPM or fuel settings may void your warranty and if you have any doubts about your abilities, please take the engine to a reputable diesel tuner.
When choosing injectors don’t go over the top work out what you need in power and chose an injector to suit as too much fuel is deadly to your engine with potential for overheating and cylinder glazing. The guys at Power Driven Diesel have some very good info in their YouTube videos and they list injectors by HP rating on their site to make choosing an upgrade much easier: https://powerdrivendiesel.com/.
Now as you are about to increase fuel and boost pressure, to do it with a degree of safety so as not to harm your engine install a turbo boost pressure gauge and an EGT/Pyro Gauge (Exhaust Gas Temperature Gauge) with an alarm, so you can keep an eye on the temps while on big drags up hills and for tuning. A pre turbo normal loaded temp towing will be around the 650C/1200F on the rolling hills with spikes for short periods on steep hills around 760C/1400F these are only rough estimates.
On the power side of things make sure you have a good high flow exhaust 3inch is plenty for 250hp with a sports muffler so your turbo can breathe as it can’t spin up properly if there is a restrictive exhaust system creating backpressure and choking your turbo.
A nice addition to these engines if you would like more than the std 2500RPM RPM is a set of governor springs in 3000 to 4000RPM and a set of 60-pound valve springs (our B210- 6BT come standard with 60lb valve springs) these will help reduce valve float and allow the use of an exhaust brake, if you go over 60 pound you will also need heavy duty push rods and from this point it starts getting expensive.
If going over 300hp with higher RPM and extra fuel, you will want a better fuel lift pump like a Airdog Raptor 100GPM 12volt fuel pump or similar lift pump. This is so you can run higher volume and pressure so the P-pump pistons fully fill through the spill port at high RPM also an adjustable P7100 pump overflow valve/return valve as it is the flow of fuel through the pump and back to the tank that cools the injection pump. When setting up start at about 30psi of fuel and adjust as needed keep an eye on your pyro gauge when doing tuning runs.
Our B-Series engines are all made with genuine DCEC Cummins components and they currently use Weifu P7100 pumps these are manufactured under license to Bosch the only part of these pumps that is different to the Bosch version as far as I know is the delivery valves so the delivery valves sold in the USA for Bosch will not fit. If you intend building to over 800hp the delivery valves will require cylindrical grinding most hydraulic workshops with machining facilities will be able to do this.
Now the Holset HX35 on most 5.9 12valve engines will get you to over 300hp but the 12 or 14cm exhaust housing is a bit restrictive and will start to choke at around 250hp this is an easy fix if you are comfortable with changing the exhaust housing on your turbo, eBay USA have 16cm, 18.5cm to 22cm housings for a couple of hundred dollars, make sure you get one with inbuilt wastegate unless you want to use an external waste gate. Again, have a look at some of the videos done by Power driven Diesel www.youtube.com/channel/UCpcor2FrquP_vAY6ltwTPOA.
Add to this a new adjustable waste gate actuator or boost controller so you can increase the boost pressure this Pressure will be different on every rig as it is not psi you need it is air volume/mass and this will change with temperature and the restriction you build into your intake system with bends and intercooler. The P-7100 injection pump has an automatic fuel to boost compensator the FAC (Aneroid Fuel Control) that will automatically add more fuel to suit the boost pressure. You can add more fuel through the boost compensator and the fuel plate will also alter your torque curve.
When I am asked for a torque figure for a certain HP I just double the HP this will give you the approx. FT LB torque value then convert this to Newton Meter online if dealing in metric, the actual torque value is a function of the fuel torque plate and tuning. This can be slid forward or backward for fine adjustment and you can buy off the shelf fuel plates to suit your torque requirements or if you just want to soot the neighbourhood.
With some mods this standard 12mm P-pump can deliver well over 800hp. This site has some good info on doing these alterations, but if you are not sure of your ability take it to a professional tuner. http://dieseldatabase.com/turning-up-a-p7100-pump/?id=58 Well, there you have it very simple, but remember to get higher HP will require the burning of more fuel this will increase your fuel consumption Another product of burning this extra fuel is heat so make sure you have a good cooling system remember you can’t destroy energy so you have to move this extra waste energy/heat out of the engine via the Radiator, make sure you have a good one!!!! Have yours professionally cleaned to get rid of scale from the old engine or even better buy a new upgraded radiator they are much cheaper than a new engine.

6BT Patrol conversion
A lot of guys buying our 6BT 5.9 12valve Cummins engines to convert their 4×4 have asked me how to do the conversion so I have put this together much of this applies to most vehicles not just patrols.
This is just an over view of how Dan my son and I handled our 5sp manual GQ Patrol 6BT Conversion, this is not how it must be done this is just how we did it along with some links to suppliers.
We started with a GQ Patrol with a TB4.2  with everything standard, to make removal and install a little easier we removed the front radiator top support:
· 50mm body lift kit  
· 22mm Radius arm spacers, these will move the front suspension forward 22mm
· Moved the transmission back 32mm and down 12mm to do this I used 2 x 150mm x 150mm x 12mm steel plates. These were placed between the gearbox cross member and the chassis rail, these were drilled in 6 holes the front 2 holes bolt the plate to the chassis, the second row of 2 holes allow the bolt to pass through the crossmember and the plate then thread into the rear chassis threads for the rear 2 bolts we drilled through the cross member and the hole in the plate was threaded M12 to except the bolt, a crush tube spacer was used so as not to squash the crossmember.
· Front springs were beefed up using Kings springs they can advise on the correct spring for your requirements just ring the factory.
· The oil pan will need to be modified, as there are many variants in pan design, the easiest way is to drop the vehicle onto the bump stops and allow a good 35mm or more clarence to the pan from any front axle or steering linkage potential impact points. For ours we took a 19mm wedge out of the front of the oil pan storage.
· For the exhaust manifold we used a Dorman manifold off ebay USA and modified it to take the 38mm external wastegate these weld quite well if heated first and high silicone mig wire is used.
· For the exhaust we took the 75mm mandrel pipe from the turbo and blended it with the 38mm pipe from the wastegate (this part is visible in the engine Bay photo) into a 100mm by the intake plenum with a stainless V-band to a 100mm flex pipe then 100mm mandrel pipe with a sports muffler to the rear. We wrapped the entire exhaust from turbo to past the clutch slave cylinder.
· Internal work was limited to 60lb valve springs our modern 5.9 engines come with 60lb valve springs all round and also don’t require (KDP) timing cover Dowel pin mods like the old Dodge Cummins engines.
· For engine mounts we used full capture bushings but for patrol 5sp manuals this guy makes a top kit https://thomas4parts.com/cummins-4×4-conversions/
· For tuning spend some time looking at Power Driven Diesel videos covering injection nozzle selection, turbo selection and tuning, also try this site for more info on how your P-pump works and is tuned
https://dieseldatabase.com/turning-up-a-p7100-pump/?id=58&fbclid=IwAR252cAHFt75qbAM_zyVULe6Lnj2rfEFpVGecSxEwpvWYPHsDcLVN00gMoc 
· For the turbo we used the std HX35 with a non-wastegated 18cm Exhaust housing off ebay usa when detuned for sale prior to this we had a non-wastegated 22cm exhaust housing
· On the fuel side we used a airdog 12volt lift pump at 50psi 150gpm and a torque teck relief valve/Overflow valve on the P-pump and 5x 0.016”145deg VOC injection Nozzles this setup will give you enough fueling for up to 600hp but a bit sooty at low boost pressures. You always want good fuel flow through the P-pump as this is the main method of cooling the P-pump
· Front mount Intercooler was a 75 x 300 x 600 with 75mm in and out from ebay
· Radiator was a triple core 75mm full alloy from Ebay
· Cooling was 2 x Thermo-fans and had no heating problems in central Qld as the 6BT have excelent
· Snorkel was a 100mm bonnet exit from patrol doctor
· The most important item is a good pyro Gauge preferably with a programable alarm, for the most accurate reading the probe should be before the turbo as the turbo will cool the gasses dramatically during the energy transfer
· Wiring is very simple with only 5 wires after the starter and earths for most applications so don’t go buying an expensive 6BT wiring harness.
· A 6BT conversion has never been so affordable with our install ready 6BT selling for under AUD$11,500 inc GST, if you would like more info on our engines or doing up an old genset or dodge Cummins just give me a call I will help where I can.