Cummins 6bt or a 24 valve engine ????

I am building a 1989 Chevy 383 TPI + tuned port injection + engine . It has a hot roller comp cam , roller rockers , 10 to 1 compression aluminum heads and a bunch more performance parts to make at least 400 HP and 400 FT torque . With the TPI set up I will make a lot of torque down low where I will need it being a mostly off road truck . It seems like everyone wants a 1989 to 2002 6bt cummings engine with around 175HP and 450 FT torque . so here is my question why does everyone want the 1989 to 2002 6bt and not the 2003 24 valve engine and up that makes a lot more HP and torque ???????? why do they want the 1989 to 2002 6bt over the 2003 and up 24 valve engine ?????????

The 12 valve (1989 to 1997) found in Dodges... (or school buses until 2002) has either the VE Rotary injection pump (1989-1993ish) or the P-pump(1993+). Both of these pumps RELIABLY can make additional horsepower with just a flathead screwdriver. Add a governor spring into the VE pump, or a fuel plate into a P-pump and it can REALLY wake up. (500-600 ft lbs easy).

These pumps (12 valve motors)also require only power to a fuel solenoid and the starter. They are easy to work on, easy to wire, easy to maintain and are known for reliable fuel delivery.

The 24 Valve came about with the VP44 injection pump in 1998-2002. VP44 is known for higher failure rates, not easily modified, and fuel conditioning (filtering) is VERY important for this pump to remain operational. Wiring, throttle position sensing, and emissions start to play a role on these motors. These pumps (VP44) also have fuel delivery ceilings MUCH lower than that of its elder 1994-1997 P-pump brother. IE the P-pump can actually make MORE power than a VP44. (So its less reliable, harder to modify, harder to maintain, and actually makes less power when turned up). VP44 injection pumps in 24 valves are known to be thrown away and guys will actually swap a 12 valve P-pump injection pump onto a 24 valve motor.

After that its an 2003+ ISB motor which is DEFINITELY more wiring complex.

My 1993 Cummins 5.9 "6BT" with the Bosch VE is known more for MPG that its P-pump brother, but "stock form" is 160HP, 420 ft lbs of torque. I have turned up the fuel screw a few turns and an updated governor spring installed. I will be around 200 HP and 500 ft-lbs of torque. All while pushing the M715 around at probably 15-17 MPG. (which is good for our heavy lego-block trucks)

Great info Venom. Thanks.

HEY VENOMINJECTED thanks a lot you really woke me up on the 5.9 engine . I was going to go with a 2007 and up but after reading your post im going with a 12 valve 6bt 1989 to 1997 thanks a lot great post !!!!!!

WHAT about a 2003 cummings ? can I turn up the fuel injection pump with the screw and gov spring or a fuel plate like the 1989 to 1997 ?? also if I can will it increase the HP and torque like the 1989 to 1997 will ? is the 2003 able to increase HP and torque without being PROBLEMATIC . also can I upgrade the fuel injectors to increase more HP and torque above the gov spring and turned up screw or is upgrading the fuel injectors a moot point over the screw and spring increase of HP and torque on the cummings from 1989 to 2003 engines ???????

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Originally Posted by venominjected

The 12 valve (1989 to 1997) found in Dodges... (or school buses until 2002) has either the VE Rotary injection pump (1989-1993ish) or the P-pump(1993+). Both of these pumps RELIABLY can make additional horsepower with just a flathead screwdriver. Add a governor spring into the VE pump, or a fuel plate into a P-pump and it can REALLY wake up. (500-600 ft lbs easy).

These pumps (12 valve motors)also require only power to a fuel solenoid and the starter. They are easy to work on, easy to wire, easy to maintain and are known for reliable fuel delivery.

The 24 Valve came about with the VP44 injection pump in 1998-2002. VP44 is known for higher failure rates, not easily modified, and fuel conditioning (filtering) is VERY important for this pump to remain operational. Wiring, throttle position sensing, and emissions start to play a role on these motors. These pumps (VP44) also have fuel delivery ceilings MUCH lower than that of its elder 1994-1997 P-pump brother. IE the P-pump can actually make MORE power than a VP44. (So its less reliable, harder to modify, harder to maintain, and actually makes less power when turned up). VP44 injection pumps in 24 valves are known to be thrown away and guys will actually swap a 12 valve P-pump injection pump onto a 24 valve motor.

After that its an 2003+ ISB motor which is DEFINITELY more wiring complex.

My 1993 Cummins 5.9 "6BT" with the Bosch VE is known more for MPG that its P-pump brother, but "stock form" is 160HP, 420 ft lbs of torque. I have turned up the fuel screw a few turns and an updated governor spring installed. I will be around 200 HP and 500 ft-lbs of torque. All while pushing the M715 around at probably 15-17 MPG. (which is good for our heavy lego-block trucks)

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Originally Posted by randall555

WHAT about a 2003 cummings ? can I turn up the fuel injection pump with the screw and gov spring or a fuel plate like the 1989 to 1997 ?? also if I can will it increase the HP and torque like the 1989 to 1997 will ? is the 2003 able to increase HP and torque without being PROBLEMATIC . also can I upgrade the fuel injectors to increase more HP and torque above the gov spring and turned up screw or is upgrading the fuel injectors a moot point over the screw and spring increase of HP and torque on the cummings from 1989 to 2003 engines ???????

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Anything 2003+ will be ISB fuel common rail injection pressures. These motors are computer controlled and will be very complex to integrate/wire without heavy electrical knowledge.

The VE and P7100 engines are stupidly simple. The VP44 and common rail engines have some advantages over the old engines, but they are far more complex and nowhere as bulletproof. And when they break, they are typically much more expensive to fix.

These engines are not for everyone. I love mine, but they are very, very noisy and with diesel being much more expensive than regular gas, you have to give it some thought as to what is best for your needs.

So the 12 valve is much easier to install because there is no wiring per say like a 2003 + and up but if someone had the ability to install a 2003+ into the truck what would be the pros and other than the wiring what would be the cons . what is the max hp and torque you can get from the 12 valve and what do you have to do to get the gains . I see where the newer engines have a higher hp and torque rating so can you add things like the fuel injectors and other parts and a computer tuner to increase hp and torque to the newer 24 valve engines ?? also if you increase hp and torque on any of these engines will it decrease the miles per gallon fuel rating . also does the older or newer engines get better mpg ???? im looking for 450 hp with 800 ft of torque so is this possible with the 12 valve 89-97 engine . also im looking for a auto trans with overdrives of .89 and .64 so when I hit 5th it will drop rpm and when I hit 6th the rpm really drops . and this is with a 4th of 1.0 . I would like to use a Allison of some type and a 700r4 as a last resort . but I don't know if I can get a 700r4 to bolt up ? I would think of some type of adaptor plate but im sure it would be a big dollar item that I don't want to pay . what Allison did they nominally put behind the cummings with overdrive or overdrives ??? oh and by the way all the wiring is not really a big deal to me I am a Electrical Engineer . I have designed and built test panels and fixtures that have over 50 ,000 points of wiring .

I vote for the p7100 or ve 12v. Mechanical is the way to go.. i have a p pump 12v in my m715 and could not be happier. Simple and effective, i can get around 15 mpg with stock axles with 42" tires if i drive like a "old man".

I deleted about all electronics down to the fuel shut off.. also kept the factory intercooler and machanical fan... all hoses are also dodge. Tight fit but cut to fit..

I have to say that im leaning to the 12valve because of the simplicity reliability and being easier to install . but what can I do to get the hp and torque up besides the screw on the fuel pump . also on a stock 12valve how much hp and torque can I get from just this screw and spring governor upgrade ?? on the 12valve I would really like to have a MININUM of 300 hp and 600 ft torque . if I change the injectors how much horse power and torque can I get just from this . also what else can I do other than a bigger turbo because I really don't want to spend the money for this . and for the 1998 to 2004 I think is a 24 valve with a computer but you can install a p7100 fuel pump like on the 12 valve is this correct ??? im thinking about this set up a 1998 to 2004 24 valve with a p 7100 fuel pump ( screw / spring upgrade ) with upgraded injectors and a computer tuner . has anyone out their done this ????? also what auto transmissions goes behind the 12 v and 24 v ?? and is 1 auto better than another trans and I would rather have a married unit like a np 205 but will go divorced if need be .

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Originally Posted by 68kaiser

I vote for the p7100 or ve 12v. Mechanical is the way to go.. i have a p pump 12v in my m715 and could not be happier. Simple and effective, i can get around 15 mpg with stock axles with 42" tires if i drive like a "old man".

I deleted about all electronics down to the fuel shut off.. also kept the factory intercooler and machanical fan... all hoses are also dodge. Tight fit but cut to fit..

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