Help choosing best motor for fummins conversion

B

Baron85

New member
Joined
Feb 27, 2017
Messages
79
I just picked up a project truck, a 2002 f350 crew cab long bed 4x4 with a locked up 5.4 gasser. My last truck was a 2004 6.0 with all the basic mods plus 58v ficm, powermax turbo, regulated return fuel, and elite and innovative custom tunes. I liked the top end power on the freeway on my 6.0 but felt the bottom end was lacking along with poor fuel mileage and constantly in the shop. I have been dreaming about this swap since I sold that truck.

I need help deciding which generation cummins will best fit my goals. They are as followed, mostly in order.

1) reliable and durable
2) driveability ( cold start, towing, noise, high elevation, throttle response)
3) fuel mileage
4) cost of ownership and long term maintenance (injectors, injection pump ect)
5) more power than my last 6.0 which should have been around 400hp 750tq???


Initial cost of the swap is not as important as long term cost of ownership. I am currently at a job making great money but we are planning on moving back to the Rockies and we are expecting an approximate 50% pay cut, hence wanting to build this right the first time while I'm making good money.

Truck will be used as a daily driver, and tow vehicle for our rock crawler and rv which gross around 22k. It will have a 6 speed manual, most likely a zf6 unless I find a great deal on a g56 or nv5600. And would like to run an exhaust brake.

My experience with cummins trucks has been 24 valves and common rails both 5.9 and 6.7. And the only modified cummins has been 1 early common rail with some type of tow tuner and exhaust and intake, as well as the fastest diesel I have been in a 24 valve with upgraded injectors, turbo and all the supporting mods. I was honestly a little disappointed in the commonrail but know it was a towing tune and that they can make mega power. The 12 valve interest me due to being all mechanical.

What will be the drivability differences between the different generations at the same power level? Say all are 450hp will one have less turbo lag? Better fuel mileage? More durable? Tow better? How would the driveability vary if all were the same power? I also know that there are a ton of variable on that question since there are a lot of ways to get to the same power level and different components with create different characteristics but hoping for general rules of thumb.

Thanks for your help.
 
Thank you for the reply.

My concerns with the commonrail are the cost of injectors which seem to be a common failure/wear item and the possibility of melting pistons.

And I know the vp44 wears out but doesn't sound like it causes and other damage when it dies and priced around $1k I don't feel is too bad

Could someone that has driven all 3 of these give me some feedback on the pluses and minuses of each motor based on my goals and uses?
 
Thinking from your point of view if I was building it. 12v is noisy and realiable and possibly smokey and won't tow as well as the others. 24v is noisy and reliable if you keep good fuel pressure too them and will tow better than the 12v. 5.9 and 6.7 CR is quiet and reliable with good tuning and fuel filtration and either will tow better than a 12v or 24v. If it was me I'd go CR and never look back.

And yes I have driven all 4. I like my 12v but it's in a ratty old first gen that never tows.
 
Last edited:
Exactly what Ddually said. I have a p-pump 24v in my 72, a VE 24v in the wife's Excursion, and a CR engine project that will go in one of them soon. :)
 
I've owned a 12v ve through 5.9 commons rail. If I was to choose I think I would go with the 12v p7100. It will be noisier than the CR but it's the most reliable and good towing power can be made and should be the easiest to swap since it use the least amount of electronics. Lots of support for it as well. And I don't think anyone can argue that it's the most reliable out of them all.


Sent from my iPhone using Tapatalk
 
When you say tow better, could you be more descriptive? Not trying to be a pain just trying to learn. Is it a broader power band, better EGT control? Fuel mileage? Ect.

Thank you both for the replies so far.
 
As far as difficulty of the swap, I'm not overly concerned. Just looking for the best that fits my goals. Seems all these options have been well documented and supported. I have not done much reading on the 6.7 swaps.
 
I'm currently looking for the right project truck. I want a 08+ f250-350 single wheel, and planning on a p7100, 6.7 24v, set of 12v rods and a 66sxe is my plan at the moment. Just haven't found a truck I'd be happy with yet.
 
I am really leaning toward the 24 valve, it just seems like a much simpler operating system with less things to try to diagnose if there is a problem. I would love to do a commonrail but the more I research it just seems that the commonrails are going to be a much more expensive long term maintance. At the lower levels I'm looking for either should get me there, with the commonrail being quieter and easier to control the smoke.

How bad are the commonrail injectors for 2003-2004? Some of my reading makes them sound like a 100k mile wear item, much like the VP pump. Is that an accurate assessment? I know there are always ones that last forever and some that die young. But average consensus longevity of commonrail injectors vs the VP pump. 1 set of injectors without melting a piston buys me 3 VP pumps.

Please keep the opinions and advice coming. I looked at a VP donor truck today and going to look at a 2003 donor tomorrow.
 
Vp's are cheap to make power with and will have better dribability than a 12v in the 400hp range, much more than that and it's nearly impossible to clean the smoke up. The CR would be the nicest to drive and tow with but it's going to be many more thousands of dollars to get it together.

Sent from my SM-G930V using Tapatalk
 
The nice thing about the VP is, that you have some options for gauges and tuning that you won't have with a 12v. I used to hate VP 24v's about 6 plus years ago. I have grown to like them now. I'm half tempted to put my VE one back to a VP. It'll have to die first thogh. :) I do like the thought of the CR's. It's just the dang cost of parts that kills it. Fuel system parts add up real quick.
 
Everyone hates on a vp because injection pumps fail... well that's basically all that goes wrong and it's still cheaper than a set of Cr injectors.
 
BRE said:
Everyone hates on a vp because injection pumps fail... well that's basically all that goes wrong and it's still cheaper than a set of Cr injectors.
Click to expand...

Yeah right. ECM's, wiring, freeze plugs/soft plugs, exhaust manifolds, and garbage lift pumps. They have their issues too. I've worked on a lot of VP trucks the last 2 years especially. Granted, they can still be cheaper than a CR, replacing a new ECM isn't exactly cheap. You have to be resourceful on some of it. Haha
 
DieselWrencher said:
Yeah right. ECM's, wiring, freeze plugs/soft plugs, exhaust manifolds, and garbage lift pumps. They have their issues too. I've worked on a lot of VP trucks the last 2 years especially. Granted, they can still be cheaper than a CR, replacing a new ECM isn't exactly cheap. You have to be resourceful on some of it. Haha
Click to expand...



Yea I still view them as a 10thousand time better truck than any common rail ever will be.
Yes... I own a common rail lol
 
24V with P7100 and mild twins and a nice cam.
It should have no natural enemies...

Sent from my XT1575 using Tapatalk
 
I actually found a wrecked 2001 that's been converted to a p pump. Going to try and look at it this week. I think I will be happy with any of them guess I will just see what pops up for the right price. Looked at a 2003 yesterday with 140k on it but looked like it was very neglected and had lots of blow by so I passed.

And the tubeability of the VP using the new adrenaline is a big draw along with the more simple design. But I also think that a p pumped motor would be fine with the use of afc live.
 
Last edited:
I've been selling a LOT of VP44 ECMs, as of late.
15+ years of grease, water, salt, heat and temperature extremes takes it's toll.

ECMs and the pumps are the biggest reasons I wouldn't use one in something I want to be reliable and cheap.

Hands down, a P-pump is where its at.

Mark.
 
Baron85 said:
I actually found a wrecked 2001 that's been converted to a p pump. Going to try and look at it this week. I think I will be happy with any of them guess I will just see what pops up for the right price. Looked at a 2003 yesterday with 140k on it but looked like it was very neglected and had lots of blow by so I passed.

And the tubeability of the VP using the new adrenaline is a big draw along with the more simple design. But I also think that a p pumped motor would be fine with the use of afc live.
Click to expand...
I am an electronic kind of guy, but I don't like the thought of being tied to hardware whose company may or may not exist by the time the part fails.

Sent from my XT1575 using Tapatalk
 
You must log in or register to reply here.
Back
Top