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12v, 24v, or powerstroke 7.3

26528 Views 19 Replies 8 Participants Last post by  jgage916
I know im on a cummins forum, but i jus wanna know why I should buy a cummins over a stroke and if i should go 12 or 24v.

Ive got about 10k to spend (give or take a grand or two depending on the condition of the truck)

Either way i go it will be a manual 4x4.

Thanks
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Narrow your search down to either a 12 Valve, or 7.3 'Stroker. Both are very reliable engines (with the 12 Valve proven to be the more reliable, but that is expected) and from what I understand the 7.3 is pretty gutless in stock form.

With a 12 Valve you never have to mess around with any computer crap to make power, which is a huge plus in my opinion, and is one of the reasons they are so damn reliable. Don't listen to people saying the truck falls apart, because even in the rust belt, all 4 of our 12 valves, haven't had a single problem. Ford also builds a very good quality truck, however I'm not a fan of the syling, but I do like the OBS Fords.

10K could buy a very nice, rust free, 4wd, 5spd 12 Valve, but I'm not sure on what the PowerStroke sells for in good shape. The best advice is just go out and test drive a few 12 Valves, and a few 7.3 'Strokers and see which you like the best.
 

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Well im not as biased as you would think, i would never buy another powerstroke, but i grew up on only fords, and i still have a soft spot for nice superduty, but after having 2 cummins, a 24 valve and a common rail, i would never go back. The older powerstroke will run forever, and so will the 12 valve, but add a few minor performance mods, like just an air intake, exhaust and some kind of fuel mod, and the dodge will be more powerful, still last longer and make more power. The fuel system on the 7.3s was just not that good. Thats just my .02...regardless of what you pick they are both good...
 
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Discussion Starter · #6 · (Edited)
Narrow your search down to either a 12 Valve, or 7.3 'Stroker. Both are very reliable engines (with the 12 Valve proven to be the more reliable, but that is expected) and from what I understand the 7.3 is pretty gutless in stock form.

With a 12 Valve you never have to mess around with any computer crap to make power, which is a huge plus in my opinion, and is one of the reasons they are so damn reliable. Don't listen to people saying the truck falls apart, because even in the rust belt, all 4 of our 12 valves, haven't had a single problem. Ford also builds a very good quality truck, however I'm not a fan of the syling, but I do like the OBS Fords.

10K could buy a very nice, rust free, 4wd, 5spd 12 Valve, but I'm not sure on what the PowerStroke sells for in good shape. The best advice is just go out and test drive a few 12 Valves, and a few 7.3 'Strokers and see which you like the best.
Thanks for the info. I agree that the OBS fords looks better than the SDs.

How does the stock clutch hold up 2 adding power on the 12v?

It will be used as a dd back & forth to U of L and also some mild pullin, nothin that will even test the trucks limits tho. It will see an atv in the bed & 1 or 2 on a trailer most often but occasionally it will see a car on a flatbed.
 

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As far as i know the stock clutches wont take much if any more abuse then stock, SO you would probly wanna upgrade the clutch first and go from there.... but the search button does wonders
 
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The fueling system on the 7.3 powerstroke is a strange creature. It is somewhat complicated to make any real power from as you usually need a chip, hpop upgrade, as well as injectors.

The way the 7.3ps (older 7.3's are COMPLETELY different idi engines) injection works is there is a high pressure oil pump (hpop) that pressurizes engine oil to the tune of 2500psi or so. This pressurized oil is fed up to the injectors, and when an electronic solenoid allows it to, it pushes the injector unit to inject fuel somewhat like the camshaft on a Detroit 2stroke diesel does. As far as electronic injectors go, this is a MAJOR benefit, as the injector is not DIRECTLY opened by a weak lame solenoid as the more modern (and highly problematic) common rail injectors are.

As far as Ford engines go, I think the 7.3 is the only direct injected diesel with ANY kind of durability and reliability. The turbo is pretty big to match the displacement of the big honkin' 7.3 and so it can support significant power upgrades with the limiting factor being the lack of an intercooler. It also has a "warm up" valve on the exhaust side that with a simple programmer can be used as an exhaust brake. The valve is operated sort of like the injectors are. An electric solenoid diverts motor oil pressure from one side to the other to open and close the valve.

Sniff around on Ford Powerstroke Forum for better info on Fords.

The big benefit to the Ford with a 7.3ps is that it has good steering and suspension. The benefit to the Dodge, is it has the Cummins.
 

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Discussion Starter · #10 ·
As far as i know the stock clutches wont take much if any more abuse then stock, SO you would probly wanna upgrade the clutch first and go from there.... but the search button does wonders
In that case, what is the clutch that yall would recommend? :confused013:
 

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Im actually already a member over there too.

I asked them the same question i asked here. lol
Just out of curiosity, what did they say on the ford forum...
 

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Discussion Starter · #12 ·
Just out of curiosity, what did they say on the ford forum...
Surprisingly, they almost all said good things about the 12v. Of course, they still recommended the 7.3 but i was surprised by how many of them said good things about the 12v. One guy said 7.3 if you want a reliable workhorse or 12v for speed & easy power. There were also a few comments about the autos failing behind the cummins, but ive never even owned an auto so im not worried about that.
 

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I love the old 7.3s but i would have to say the 12v is the workhorse and speed and easy power...there is a reason you can find those engines in everything from backhoes to generators...and the older autos are prone to problems, but every one has different experiences. The only thing ive ever heard about the nv4500 in the 12 valves is the smaller clutch, but if you hop the power up south bend sells an upgrade kit so you can run the bigger new style clutch in the nv5600
 
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I'm a member over there too. :) You might even recognize my name, but I don't have much to say since I don't know much about Fords. Mostly I lurk and glean info as my local vfd has a bunch of Fords, and they are my problem (maint. officer).

I would disagree that the 7.3 should be chosen for reliability and the Cummins chosen for power. The 7.3ps has a very large turbo, and a complicated injection system. I'd put the reliability of the 7.3ps somewhere near the 24valve VP engine due to the electronics. A 12valve is PURELY mechanical. For reliability, there is NO comparison IMO. As to power, it's easier to make more with a Cummins, but you hit the limitations more quickly due to displacement having difficulty spooling a big turbo.

One more thing to think about since you are considering a stick, is that the nv4500 in a Dodge or Chevy has the 1.25" input shaft (which can be upgraded to the 1.375") and the fifth gear nut issue. The nv5600 (six speed) has no such problems, and some came with a bigger input shaft. The split is near 01 to get the 1.375" input. They are big iron monsters, though, and don't dissipate heat well. They REQUIRE synthetic. The 5600 only came behind the 24valve which is the ONLY reason I have a 24 valve.

As far as I am aware, the ZF transmission is pretty much trouble free. Tough enough to live behind a Cummins, as well. Or so I've heard! :)
 
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Discussion Starter · #16 ·
I would disagree that the 7.3 should be chosen for reliability and the Cummins chosen for power. The 7.3ps has a very large turbo, and a complicated injection system. I'd put the reliability of the 7.3ps somewhere near the 24valve VP engine due to the electronics. A 12valve is PURELY mechanical. For reliability, there is NO comparison IMO. As to power, it's easier to make more with a Cummins, but you hit the limitations more quickly due to displacement having difficulty spooling a big turbo.
What is the limit of the 12v as far as power and torque? Stock internals and bolt-ons.


One more thing to think about since you are considering a stick, is that the nv4500 in a Dodge or Chevy has the 1.25" input shaft (which can be upgraded to the 1.375") and the fifth gear nut issue. The nv5600 (six speed) has no such problems, and some came with a bigger input shaft. The split is near 01 to get the 1.375" input. They are big iron monsters, though, and don't dissipate heat well. They REQUIRE synthetic. The 5600 only came behind the 24valve which is the ONLY reason I have a 24 valve.
Can the 5600 be swapped into a 12v and if so what all is involved? :confused013:
 

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What is the limit of the 12v as far as power and torque? Stock internals and bolt-ons.

More than you need. :thumbsup:

My brother made 716rwhp with his '97, with a single turbo. He still got around 18-20mpg as well.

Can the 5600 be swapped into a 12v and if so what all is involved? :confused013:
Yes it can be swapped in, but it isn't really needed. The NV4500 is a fine transmision, as long as you get the 5th geat issue fixed (which isn't hard.) The NV4500 held up to 716rwhp, and over 1,000ft/lb of tirque in my brothers street truck, and over 1,000rwhp and who knows how much torque in his pulling truck.
 

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ok so i play w/ both beasts, i've owned a obs stroker,

had over $3000 to get like 350-400hp, the hpop system sucks, the wheel nut system is dumb as i found out 2 times when my tire came off, the one thing i have read in here that is false info, is about the powerstroke turbo, they are junk,that heater valve that your talkin about usually goes out and leaks or sticks, alot of ppl delete them b/c they do not help at all.also the turbos are not big enought, they are made to operate in like 18-25psi, my obs one did 40+ but man that is no good haha, it was ready to explode, it was gettin some major play in it, ohhh and the stock clutchs in the ZF-5 are dual mass fly wheel = junk!!! the superdutys have the ZF-6 = strong

so basically if your goin for your money your best bet if you want some extra power either get a SuperDuty or a 12v, as far as OBS Strokers go, they are good if you have money,
 

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I defer to your experience, but I DID say that the limiting factor of the 7.3ps is the lack of an aftercooler, which makes high boost numbers useless as the adiabatic heating of the air charge overcomes the pressure of the boost, and makes it less powerful, and much hotter. However, a 7.3 sucking down 15 psi is making a LOT more (23% give or take) power than the 5.9 at the same pressure with no aftercooler.

I would disable the warmup feature myself, as it just burns fuel unnecessarily, but as an ENGINE BRAKE it is a very good bargain.

Dual mass is a bummer. I forgot the ps got them.

As to the swap, personally I'd upgrade the clutch, 5th nut, and input shaft on the 5speed nv4500 rather than swap to a 6 speed unless you tow A LOT. It's a pain to drive. I hit 3 gears going through an intersection. Even with 3.55 gears and 35" rubber. The 4500 ratios are VERY close for first, reverse, overdrive, and direct drive. (dd is 4th in the 4500, 5th in the 5600) In the 5600, you get one more gear between first and direct. Oh and there are parts availability issues with the 5600. I'd consider the aluminum (yay!) cased Getrag 6 speed for that reason. Plus you can buy a brand new one from the factory.

The limitation of power on the Cummins is pretty much the small turbo required to match the small displacement. I don't know too much about the various turbos, but the hx on mine is good to about 350hp with the boost turned up to 35 psi. I am fueling somewhere near 400hp I think (pretty much the limit for my stock turbo) . I'd do a search, but I think the stock longblock is good to just about 500hp before you need studs. Retorqueing the head to a higher torque is a common practice at the upper end of the stock longblock limits.
 
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I defer to your experience, but I DID say that the limiting factor of the 7.3ps is the lack of an aftercooler, which makes high boost numbers useless as the adiabatic heating of the air charge overcomes the pressure of the boost, and makes it less powerful, and much hotter. However, a 7.3 sucking down 15 psi is making a LOT more (23% give or take) power than the 5.9 at the same pressure with no aftercooler.

I would disable the warmup feature myself, as it just burns fuel unnecessarily, but as an ENGINE BRAKE it is a very good bargain.

Dual mass is a bummer. I forgot the ps got them.

As to the swap, personally I'd upgrade the clutch, 5th nut, and input shaft on the 5speed nv4500 rather than swap to a 6 speed unless you tow A LOT. It's a pain to drive. I hit 3 gears going through an intersection. Even with 3.55 gears and 35" rubber. The 4500 ratios are VERY close for first, reverse, overdrive, and direct drive. (dd is 4th in the 4500, 5th in the 5600) In the 5600, you get one more gear between first and direct. Oh and there are parts availability issues with the 5600. I'd consider the aluminum (yay!) cased Getrag 6 speed for that reason. Plus you can buy a brand new one from the factory.

The limitation of power on the Cummins is pretty much the small turbo required to match the small displacement. I don't know too much about the various turbos, but the hx on mine is good to about 350hp with the boost turned up to 35 psi. I am fueling somewhere near 400hp I think (pretty much the limit for my stock turbo) . I'd do a search, but I think the stock longblock is good to just about 500hp before you need studs. Retorqueing the head to a higher torque is a common practice at the upper end of the stock longblock limits.
Ill agree with most of that, but i LOVE my NV5600, one day im hoping to get a 2door 2500 12 valve to build as an off road truck, and its gonna get a 5600. I put 50k a year on mine and its easy to drive...But as far as the performance side, you keep going back to the small turbo, but either you want to keep it more on the reliable side, and keep the mods simple and the turbo is fine, or you go a little milder and you should probably go with a different turbo anyway to support the fuel mods, that just the way it goes. Turn the fuel up and you need more air, the same goes for the powerstroke. The difference is the turbo on the powerstroke supports more mods cause it takes more mods to make the fords fueling system to make the amount of fuel of the P-pump. It seems to me like you either get the inferior fuel system or the smaller turbo...if im wrong by all means correct me but that seems sensible to me.
 
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