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rdsutton

2nd Gen. 24V convertion to 12V

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Would like to ask if anyone on this form has any experience converting a 24V to a 12V. to include: injectors, injector pump, lift pump/heater, and fuel delivery from tank to engine?? Estimated COST, Shop Vs DIY?? Any and all input will be greatly appreciated.. Oh Yes, I'm a newbe to this form, and I have read ALOT of well written post in here on 2nd gen and 3rd gen tecnical topics. I'm currently loking at a 98 5spd CC 4X with 132K, I have'nt ruled out the evil 53 block yet on it, but the rest of it looooks way sweet and matches the miles.. Thanks again to all who read and post.

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a new vp, lift pump and fp gauge can be had for about $1500 to $1800 depending on what pump you choose. if your vp is still good $800 or less will set you up.

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You may be money ahead to consider buying a nice 12 valve rather than the 24 valve and converting it. Things have a way of getting real expensive with just general maintenance and repairs.

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Couldnt agree more with the above posts on the 24v, get you a fuel pressure gauge make sure you maintain a fuel pressure of no less than 10psi even at WOT. If the current lift pump you have cant keep a good fuel pressure look into a FASS or Airdog/raptor fuel pump for quality pumps and good fuel pressure.-Jordan-

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Ok, first my thoughts on why the convertion; The convertion I bevieve would cover injectors, injector pump, injector lines, cam and timing gears and cover, gaskets, tank to pump fuel lines, and a aftermarket lift pump, and some mics. parts. Now why; PM cost, P7100 and mechanical lift pump-rock solid reliability, You don't have to carry a spare, fuel delivery and return, and last the 12v fuel system over all IMO easy to work on with the exception of stock fuel filter. Now after recieving some feedback, first the 98.5's do not have the access on side of block for a mechanical lift pumpt, the task will reap little gain in comparison to the cost..A correct and complete covertion parts only near $4K.. If I do pick up a 98.5 I'll hopefuly pick up a well maintained one, and add a aftermarket lift pump and fuel guage.. Thanks for input and interist.

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Ok... Let me let you in a secret... I live in the middle of nowhere Idaho. I travel great distances just for basic things like groceries is a 70 mile round trip. Auto part store is 104 miles round trip. WalMart is worse at 350 miles round trip.There is 3 thing the VP44 need to run a long happy life won't needing to pack around spare any thing...1. Good fuel pressure and volume. You fuel pressure should always be 14-20 PSI with only a 2-3 PSI fall from idle to WOT at highway speed.2. Good fuel filters. You stock filter can is OK if you use a high quality filter. Should try to get below 10 micron. AH64ID is the filter guru of the site.3. Lubricity. Bosch design the pump around <450 HFRR lubrcity and today's fuel is ~520 HFRR so the higher the HFRR number the less lubricity and more wear occurs. My VP44 has performed remarkably well I've got a AirDog 150 with 2 micron filters and 128:1 shot of 2 cycle oil in the fuel. I'm coming up on 150K on the clock for the VP44 and the truck is coming up on 200K miles.Vp44 fuel system are rather good performing don't fail if you understand the weakness of them. Like you mention the wanting the Ppump for it being fully mechanical. Well it got few weak points too like the mechanical lift pump is not efficent at high RPM's it start losing volume. The list go es on too...

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Mopar1973man, 1st I do respect your time and you replys on this matter. My "carrying a spare around" comment, well most of what I read about late 2nd gen are fuel related and come from reading trouble shootin articals/replys in publications and forms. I'll try to read more positive articals. May be I'm crosseyed and leary about the whole fuel issue. Like you I am out 75 to 200 miles from my garage, and when when i'm in south east CO on the ranch 75 to 200 mi from any service.. I like to think I have a good level of comfort in the rig I drive. As you pointed out in your secret, know the fuel systems limits and keep it healthy and happy.. Respectfuly I know all CTD's will have sweet and sour spots. I just want more sweet ones. Thank you Dave.. BTY Mntom refered me to this well informed forum. I'm glad he did and I hope not to have offended anyone. Dave

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Plenty of guys doing the P-pump conversion on 24V trucks. A lot of it is because they are tired of replacing VP44's that fail from higher hp trucks. The VP can move enough fuel, but doesn't last like P-pump will. If your talking a mild motor then you are $$ ahead by maintaining a VP, but a 24V P-pump is a great motor!

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Mopar1973man, 1st I do respect your time and you replys on this matter. My "carrying a spare around" comment, well most of what I read about late 2nd gen are fuel related and come from reading trouble shootin articals/replys in publications and forms. I'll try to read more positive articals. May be I'm crosseyed and leary about the whole fuel issue. Like you I am out 75 to 200 miles from my garage, and when when i'm in south east CO on the ranch 75 to 200 mi from any service.. I like to think I have a good level of comfort in the rig I drive. As you pointed out in your secret, know the fuel systems limits and keep it healthy and happy.. Respectfuly I know all CTD's will have sweet and sour spots. I just want more sweet ones. Thank you Dave.. BTY Mntom refered me to this well informed forum. I'm glad he did and I hope not to have offended anyone. Dave

Your statement is well informed and nobody should be offended by it. When you go to any 24V forum, you read about people changing out VP44's left and right, not exactly a good feeling about something you are wanting to buy. Now part of the problem probably stems from ignorance. A while back the knowledge was not very well distributed about the VP's need for constant good pressure. A lot of people still don't realize it though, and those are the ones who end up on the forum wondering why their VP is dead. It has created a sense of unreliability pertaining to the VP trucks. Knowing the information on how to maintain it is key. I realize with the Ppump you can get in and drive it and be fine with just knowing general maintenance techniques. It is a bit different with a VP since you have to watch a fuel pressure gauge your whole life. I don't think you could convince Mike to throw his fuel pressure gauge away along with all other fuel pressure monitoring devices. Most 12V guys know all about fuel pressure but could care less about a gauge, after all, if our lift pump goes out, the worst that could happen is the truck quits running.. There are instances where the plungers could stick but that seems a little rare. The biggest factor is the reliability of those aftermarket lift pumps (the air dog) that people run on the VP to "fix" the issue. They provide the fuel pressure needed to keep the VP happy. However, I have no idea how reliable those pumps are. It is an electric pump though, not mechanical like the 12V uses, this means there is questionable reliability in something electronic as with any electronic thing. There is a reason the oil pump is gear driven, not belt driven, not electric. Mike takes his airdog apart to keep it running strong, changing out o-rings in it and such.

The biggest factor with all of this is that when the truck dies out in the middle of nowhere, you are much more apt to limp home with a 12V than a 24V. The mechanical lift pump will die on you slowly, you will be able to tell because power will decreases slowly (as in several thousand miles). It isn't the fact that either truck might have issues, it's the fact that the 12V gives you more time to let it know that it's about to break something. Lately it seems like a lot of 24V ECM's are going out, the 12V doesn't even have an ECM, you can drive a 5spd 12V home with no batteries or alternator whatsoever. But what ways are there to fix the ECM issue? Like I said earlier, it isn't the fact that the 24V has some issues, it's the fact that the solutions are still questionable. How do I know the airdog will last 100k miles? How do I know the ECM isn't going to die?

If we say that those issues are resolved, we still get back to the fact that there are a lot of unknowns about the VP. Nobody has a clue what the timing is on a VP other than a chart which I can't read the numbers on. That chart doesn't show how the IAT or ECT effect it either. This actually isn't really an issue other than the fact that if you were in Antarctica with a screwdriver and pliers and it was -100F out and the truck died, you could probably rig up something to get the 12V to the south pole warehouse whereas you can only do so much to a 24V without needing very advanced tools.

Personally, I see no advantage to owning a 24V over a 12V.....in Florida. If you live somewhere that gets under 32F regularly, it is definitely nicer having a truck that can easily be rigged to warm itself up (3 cyl high idle), maintain 800RPM idle automatically, and do all the other crap that it does in the winter. I do hate the knocking they make in the winter but apparently the IAT fooler smooths that out.

You seem to be set on converting to a 12V and although I can see it both ways, I still have that thought that if I had a 24V, the VP would just die on me. But then again, what's to say Mike's truck's VP won't last forever now that he has modded it all to perfection? We only have doubts because we have personally seen all the posts on forums about people's VPs going out. Mike's hasn't gone out yet after I think 100k miles on the same VP, so if everyone's truck was set up exactly like Mike's, whats to say the failure rate wouldn't be the same as a Ppumped truck?

If you do convert it, I'd like to see pics :hyper:

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Ithink a lot of it, as well, is that those that owned a 12V first, before a 24V ownership, tends to want what they had.I'm in that category, as well. I'm dying to p-pump my 24v.Even from a mild performance increase standpoint, I made over 400HP on my p-pump truck for under $400. Do THAT with a VP truck :)But, in saying that, I'm also starting to wean off of the conversion I desperately wanted so badly..Curse you, Mike... :moon:

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:lmao::lmao2: I get a good laugh from you Rogan... Thanks...But the simple thing is with any of the Cummins line you can invest some serious money and make it bulletproof (so to speak). But Question you got to ask is how much money are you will to lay down to make it bulletproof?ISX does bring up a good point of the old 12V's and there ability to limp home with next to nothing. But once again it about being aware of your vehicle I don't care if its a 12V, 24V or CR truck each one has its sour points (as pointed out). But in any of the vehicle models it all about being aware of your vehicle and keeping the maintenance up. Like ISX point out you notice a loss of power and performance over time. Well that true with any of the Cummins models (12V, 24V, CR, Etc.) but most people tend to shrug it off to poor fuel, winterized fuel, bad hair day, wifes in a bad mood, etc. Instead of actually looking into the issue.Like on the CR engine I see more people rebuilding engines from failed injectors. Like on the 24V engine I see more VP44 failed from no fuel pressure gauge, crappy fuel, and crappy fuel filters.!2V's well they are nearly bulletproof but there is a lack of user adjustablity with the engine. Like timing a P7100 or a VE pump requires special tools to do it properly. Yes. I know ISX has a fallback plan to get stock timing. 12V's tend to do much better in the MPG department compared to any other series of engine with 6.7L being the worse in MPG's from all the smog equiptment. Now a person like ISX is knowledgable and he's very capable of doing most anything to his truck and keep it going. But from a Common Joe aspect I tend to try and keep it simple and easy.

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i came to this forum with hardly any knowledge of these trucks specificly, but i did have a genral mechanical knowledge about vehicles in general. i spent the first year here asking questions and learning. now i can answer questions aboth 24v for people that appear to know less about them than i do. thats all because of the folks here who share their with expertise and experience of all version of the ctd. The bottom line for me is taking what every one offers and doing it the way i want to without anyone calling me a total dumb ___ just because i dont see it their way. though i have had few :doh: moments because i did not listen. in the end i take what i get here and apply it how it suits me. thats something i never found until i came here. so p pump it i thats what you want after all it is your truck and you can do any thing to it you like. we just want to know how it goes for you and wish you well with it.

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Welcome aboard!In reading this through... I'm thinking the OP does not own a Cummins truck yet. If this is the case, I'd try to find a good late model 12V Cummins truck. They are out there. They have all the right parts already on them. I see take out 12Vs pretty often too. Just a technicallity but PPumping a 24 valve violates smog laws. If they require a computer scan based on year... as some do... you're out of luck. That said, a lot of 24 valve troubles are because novice diesel owners like me... were clueless about the fuel pressure issue. Heck, Dodge still is! Russ

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i would honestly have to say that with the VP having an ECU that can or will fail over time even thought the mechanical part is still good this puts it below the P-pumped in reliability. If the ecm kicks it... your just plain screwed and stuck. But i have some ideas about integrating a peltier cooler on top of the ecu to run after the truck is shut down due to the latent heat creeping into the vp with no fuel flow to cool.

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i would honestly have to say that with the VP having an ECU that can or will fail over time even thought the mechanical part is still good this puts it below the P-pumped in reliability. If the ecm kicks it... your just plain screwed and stuck. But i have some ideas about integrating a peltier cooler on top of the ecu to run after the truck is shut down due to the latent heat creeping into the vp with no fuel flow to cool.

If you have an edge juice you can see fuel temp and you will see that the heat stays there for hours. In the summer, the block remains hot for a long time and it heat soaks the VP for just as long. If you were to cool it, you would have to cool it for hours and being that peltiers are very inefficient, you would drain your batteries in no time.

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