# Trucks-12 Valve Dodge Cummins Or 24 Valve?



## CLEARVIEW TREE

Buyin another diesel truck to haul chips and really everything. I like my powerstroke and gonna keep it, but gonna buy a dodge with the Ford designed cummins engine for the better mileage. Should i get a 12 or a 24 valve? I like performance mods and the ease of programmers for 99 and newer but they say those mech. inj. 12 valves are freakin bullet proof and wicked turned up? Any help appreciated.


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## bigbadbob

The 12 valves were excellent.The 1998 12 valve quad cab is the holy grail of dodges, a little hard to find.
The 24 valve from 98.5-02 had a few issues.
Bad injection pumps, the 'KDP' pin and '53' cracking block, 5th gear nut.
The auto trans likes a newer torque conveter and shift kit also.
The 03 and up with common rail injection are excellent also.
I would stay away from the 03-04 Ford 6.0 liter they had issues.


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## CLEARVIEW TREE

Found a 98 12 valve 3500 dually with 46k original miles. An old couple close to me traded it for a jeep bout 2wks ago. The dealer is asking 9k and that's a steal. I drove the truck and it's got a manual trans and 3.55 rr gearing(yes it's 2wd) but had killer power and only turned like 1k rpm's at 60mph. Truck might just get 20mpg towing. If i get it it will become my chip truck. Just like a new one and power everything. The gas burnin chip dump's gotta go. The diesel's will get lots better mileage. Preciate the info!:monkey:


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## ACE

I agree w/ Bigbadbob. My '01 w/ 24 valve had a bad injection pump at 85k miles. Cost me $2500. Other than that I love it. Had it for 7 yrs now and plan on keeping it.


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## motoroilmccall

CLEARVIEW TREE said:


> Buyin another diesel truck to haul chips and really everything. I like my powerstroke and gonna keep it, but gonna buy a dodge with the Ford designed cummins engine for the better mileage. Should i get a 12 or a 24 valve? I like performance mods and the ease of programmers for 99 and newer but they say those mech. inj. 12 valves are freakin bullet proof and wicked turned up? Any help appreciated.



Alright. I don't know how many times I have to say this... FORD DOES NOT OWN CUMMINS! THEY HAVE NEVER DESIGNED A CUMMINS ENGINE! 

Ford used to own stock in Cummins, less than 15%. They never designed anything for Cummins, they just don't have the engineers to do so, if they did, they wouldn't have contracted the Powerchoke through International/Navistar. 

What is your main goal with the truck? Personal or business? If its business, you shouldn't be worried about turning it up. The 12V is the better of the 2 trucks, in fact, most guys who actually know diesels (no matter what brand they are bias too) will tell you the 12V is the most desirable pickup diesel you can get. Its way more overbuilt than the P-Choke or Duramax. 

You won't get 20mpg towing, it just won't happen. If you get 17-18, feel lucky. I haul various loads, but even with an unloaded gooseneck at about 4.5K lbs, I get 16.5 with my 4x4 stick shift. Unloaded you should see 20mpg easy. 

The 24V are great trucks, don't get me wrong, but the VP44 Injection pumps are anything but bulletproof. If they lose fuel pressure they'll toast themselves in a matter of minutes. If the P-Pump loses fuel pressure, it will just pull fuel on its own, or shut off. Plus the 12V trucks have a mechanical lift pump, vs the 24V's electric in tank lift pump. 

I've had 3 12V's and 1 24V... I would keep buying 12V's.


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## Torquin

Oh my, many an uninformed person here.
I've been there, done that, since I have 6 of these trucks, ranging from 1989 to 1999.
The 12v in your 98 should be checked for the KDP (Killer dowel pin). This is a dowel pin in the timing case which can works its way out of the case and fall into the timing gears. Part of the time it falls harmlessly into the oil pan and causes no other problems. The other part of the time it gets jammed into between the gears and cracks the timing case. This gives you a huge oil leak and is a real pain to repair as you must pull the front end off the truck, except for the fenders, to get the camshaft out so you can replace the timing case. This malady affects Cummins engines form 1989 up through 2000, no matter how many valves. It seems that when Cummins changed the design to make the dowel pin hole tighter they did not cut off production and start new, they just mixed the new design in with the old, so you may or may not have an affected engine in 1999-2000 trucks.
Other than that, the 12v engines, with the P7100 injector pump (94 to 98.5), are practically bulletproof.

In the case of the 24v, the VP44 injector pumps can be problematic, and will cook themselves over time if they do not have sufficient fuel pressure. This is due to the design, in that the VP44 pump uses the extra fuel being pushed to it to lubricate and cool the injector pump, unlike the P7100, which uses motor oil to lubricate and cool the pump. If you have a 24v, and do nothing else to it, you should install a fuel pressure gauge and monitor it. If it falls below 7 psi at wide-open throttle, replace the lift pump (fuel pump), which is located on the side of the engine, just above the starter, not in the fuel tank. Nowadays, if you go to replace the lift pump, and try to purchase it from Dodge, you will find that they superseded the design, finally, and have a retrofit kit that does put the lift pump in the tank. They no longer offer a replacement pump for the one on the side of the engine. This solution has not proven to be much better than the stock pump on the side of the engine.
If you want to keep the lift pump on the side of the engine you can still purchase if from a Cummins dealer. The best way to fix this, once and for all, is to install an aftermarket pump, such as a FASS, which is a much heavier duty pump that was specifically designed for this usage. After my second lift pump on the 99, I went to a FASS and never looked back.
If you are looking at a 24v engine, between 1998.5 and 2001, take a close look at the engine block. There may be a casting number under the PS pump, just above the oil pane flange, that says "53". If there is a "53" there, this is a thin-walled engine block, made in Brazil. Trucks with this block, used for heavy towing may crack horizontally down the passenger side of the engine, below the head, above the freeze plugs. I have talked to many people about this block, and experienced it personally. I would not buy a truck that has a 53 block, but that will be up to you. Many people have this block and have had no problems with it, even after more than 100K, but I cracked mine pulling a tractor over a mountain with 75K on it. It never cracked while drag racing, but that towing sure did it in. You do not lose functionality of the engine, just develop a water leak of varying size.
Everything I have stated here can be verified on several different web sites, and more info is available if you want to know. Just do searches on the various terms I have mentioned and you can't miss the info.

Chris


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## motoroilmccall

Torquin said:


> Oh my, many an uninformed person here.
> I've been there, done that, since I have 6 of these trucks, ranging from 1989 to 1999.
> The 12v in your 98 should be checked for the KDP (Killer dowel pin). This is a dowel pin in the timing case which can works its way out of the case and fall into the timing gears. Part of the time it falls harmlessly into the oil pan and causes no other problems. The other part of the time it gets jammed into between the gears and cracks the timing case. This gives you a huge oil leak and is a real pain to repair as you must pull the front end off the truck, except for the fenders, to get the camshaft out so you can replace the timing case. This malady affects Cummins engines form 1989 up through 2000, no matter how many valves. It seems that when Cummins changed the design to make the dowel pin hole tighter they did not cut off production and start new, they just mixed the new design in with the old, so you may or may not have an affected engine in 1999-2000 trucks.
> Other than that, the 12v engines, with the P7100 injector pump (94 to 98.5), are practically bulletproof.
> 
> In the case of the 24v, the VP44 injector pumps can be problematic, and will cook themselves over time if they do not have sufficient fuel pressure. This is due to the design, in that the VP44 pump uses the extra fuel being pushed to it to lubricate and cool the injector pump, unlike the P7100, which uses motor oil to lubricate and cool the pump. If you have a 24v, and do nothing else to it, you should install a fuel pressure gauge and monitor it. If it falls below 7 psi at wide-open throttle, replace the lift pump (fuel pump), which is located on the side of the engine, just above the starter, not in the fuel tank. Nowadays, if you go to replace the lift pump, and try to purchase it from Dodge, you will find that they superseded the design, finally, and have a retrofit kit that does put the lift pump in the tank. They no longer offer a replacement pump for the one on the side of the engine. This solution has not proven to be much better than the stock pump on the side of the engine.
> If you want to keep the lift pump on the side of the engine you can still purchase if from a Cummins dealer. The best way to fix this, once and for all, is to install an aftermarket pump, such as a FASS, which is a much heavier duty pump that was specifically designed for this usage. After my second lift pump on the 99, I went to a FASS and never looked back.
> If you are looking at a 24v engine, between 1998.5 and 2001, take a close look at the engine block. There may be a casting number under the PS pump, just above the oil pane flange, that says "53". If there is a "53" there, this is a thin-walled engine block, made in Brazil. Trucks with this block, used for heavy towing may crack horizontally down the passenger side of the engine, below the head, above the freeze plugs. I have talked to many people about this block, and experienced it personally. I would not buy a truck that has a 53 block, but that will be up to you. Many people have this block and have had no problems with it, even after more than 100K, but I cracked mine pulling a tractor over a mountain with 75K on it. It never cracked while drag racing, but that towing sure did it in. You do not lose functionality of the engine, just develop a water leak of varying size.
> Everything I have stated here can be verified on several different web sites, and more info is available if you want to know. Just do searches on the various terms I have mentioned and you can't miss the info.
> 
> Chris



The 24V's all had in tank lift pumps, the side of the block puumps are the mechanical plunger lift pumps, actuated by a lobe on the camshaft, and were only used on the 12V trucks from 89-98. The 53 Block is one of those things like the KDP, some people have bad luck, others good luck. I wouldn't buy one with it, but thats because I run trucks pretty hard. 

Go with the 12V, and don't second guess it, they are some of the most dependable trucks on the road.


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## Torquin

motoroilmccall said:


> The 24V's all had in tank lift pumps, the side of the block puumps are the mechanical plunger lift pumps, actuated by a lobe on the camshaft, and were only used on the 12V trucks from 89-98. The 53 Block is one of those things like the KDP, some people have bad luck, others good luck. I wouldn't buy one with it, but thats because I run trucks pretty hard.
> 
> Go with the 12V, and don't second guess it, they are some of the most dependable trucks on the road.



Sorry man, you're misinformed. The 12v engines had the mechanical lift pumps. The 24v's all had electric lift pumps mounted in the side of the engine block, just above the starter. As I said before, I've been there, multiple times. Been into the tank multiple times too. All that's in there is the fuel sending unit. I know this because I have replaced the unit on my 99 twice, another problem with the second gen Dodges.
http://www.Stamey.Info/Truck/Images/FuelTank.JPG
Notice how this TSB instructs you to disconnect or connect the ELECTRICAL connector on the lift pump when replacing it.
http://dodgeram.info/tsb/recalls/Notice878.htm

More proof I know what I am talking about:
http://www.dodgeram.org/tech/dsl/mt_2_feb98/fuel_sys_2.htm

Now, some people, in an effort to relieve their VP44 from having the problems from the faulty electric fuel pump design on the 24v trucks HAVE put a circa-12v mechanical pump on their ISBs, as the 24v block still has the hole in the side where a mechanical fuel pump could be mounted. You have to really want this because the 24v camshaft does not the the necessary lobe to drive the mechanical fuel pump on it, therefore you must install an aftermarket cam to use a mechanical lift pump on a 24v engine. I know a guy that did that too.
And, to take this even further, even the 3rd gen Dodges, with the Cummins, still had engine block-mounted electrical lift pumps on them up until at least 2005. I know this because I had to upgrade a 2004.5 to a FASS when the electric lift pump on the side of the engine block failed, and the owner decided that Dodge's price for the pump was more than it was worth, deciding to go with the FASS instead.
Like I said, been there, done that.

Chris


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## 046

you need to jump on that deal before someone else does! 

98 12v with that low of miles is bringing closer to $15k+
5sp w/3.55 are most desirable... 

most are auto... something like a 20 to 1 ratio... everyone wants a stick..but ends up settling for an auto..



CLEARVIEW TREE said:


> Found a 98 12 valve 3500 dually with 46k original miles. An old couple close to me traded it for a jeep bout 2wks ago. The dealer is asking 9k and that's a steal. I drove the truck and it's got a manual trans and 3.55 rr gearing(yes it's 2wd) but had killer power and only turned like 1k rpm's at 60mph. Truck might just get 20mpg towing. If i get it it will become my chip truck. Just like a new one and power everything. The gas burnin chip dump's gotta go. The diesel's will get lots better mileage. Preciate the info!:monkey:


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## motoroilmccall

Torquin said:


> Sorry man, you're misinformed. The 12v engines had the mechanical lift pumps. The 24v's all had electric lift pumps mounted in the side of the engine block, just above the starter. As I said before, I've been there, multiple times. Been into the tank multiple times too. All that's in there is the fuel sending unit. I know this because I have replaced the unit on my 99 twice, another problem with the second gen Dodges.
> http://www.Stamey.Info/Truck/Images/FuelTank.JPG
> Notice how this TSB instructs you to disconnect or connect the ELECTRICAL connector on the lift pump when replacing it.
> http://dodgeram.info/tsb/recalls/Notice878.htm
> 
> More proof I know what I am talking about:
> http://www.dodgeram.org/tech/dsl/mt_2_feb98/fuel_sys_2.htm
> 
> Now, some people, in an effort to relieve their VP44 from having the problems from the faulty electric fuel pump design on the 24v trucks HAVE put a circa-12v mechanical pump on their ISBs, as the 24v block still has the hole in the side where a mechanical fuel pump could be mounted. You have to really want this because the 24v camshaft does not the the necessary lobe to drive the mechanical fuel pump on it, therefore you must install an aftermarket cam to use a mechanical lift pump on a 24v engine. I know a guy that did that too.
> And, to take this even further, even the 3rd gen Dodges, with the Cummins, still had engine block-mounted electrical lift pumps on them up until at least 2005. I know this because I had to upgrade a 2004.5 to a FASS when the electric lift pump on the side of the engine block failed, and the owner decided that Dodge's price for the pump was more than it was worth, deciding to go with the FASS instead.
> Like I said, been there, done that.
> 
> Chris



Thats what I said! lol. I said "The 24V engines all had in tank lift pumps." The mechanical pumps were on the 12V's only, and they are driven off a lobe on the camshaft, bolted to the side of the block. I know... I've replaced many of them. I have NEVER seen a lift pump on the side of the block on a 24V. Not saying people haven't put them there, but I've never seen one in my years working on them. All of them were the Carter style pumps in the tank (unless it was already replaced with an FASS, AirDog, Raptor, Haisley LP, or Holley pump).

You want to know about Cummins Dodges, go to www.dieseltruckresource.com, or if you're a little more light hearted and like to goof off but still get the straight facts, go to www.dieselbombers.com. I'm on both of those sights, Bombers as the same name I am here.

I own 3 of these trucks, a 97 2500 4x4 5-spd, a 98 3500 12V 5-spd, and a 99 2500 4x4 5-spd 24V, the 99 just broke 200K miles, the 97 just broke 260K miles, and the 98 has 398k miles. Trust me, I know all 3 of my trucks inside and out. The 97 is putting down about 400RWHP, while the 98 is at 550RWHP, and is ready for another new NV4500 (the Dual Disk Clutch and 1-3/8th input shaft is way stronger than the rest of the trans), fortunately it has an NP271 T-case, so I don't need to worry about blowing that up any time soon.


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## Brimmstone

When it comes to Cummins engines both have their merits and their downfalls. Do the timing pins come out on the earlier 24v and 12v engines? Yes they do. Does the stock VP44 pump suck on 24v engines? Yes it does. I also agree that any 53 block is prone to cracking but a competent tech with Crackmaster repair pins can fix this problem in a day. The timing pin issue can be addresses and cure permanently with a little time and some tools, The VP44 can be fixed permanently with a new pump from BlueChip Diesel. I can also list you part numbers to fix the fifth gear issue in the manual trannies. I also can tell you the best converter and shift kit to use in the automatic truck. It all comes down to what you want and can afford at the time. I can also list numerous problems with the Powerstroke, Duramax, and 6.5 turbo in the older Chevys. If it was me I would be looking for 96 Dodge club cab with a stick and four wheel drive. They are out there they're just hard to find. Good luck on the hunt.


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## motoroilmccall

Just out of curiosity, why a 96?


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## Brimmstone

That was the year when nothing was really changed with the engine. I have a friend with one and at the current time it has over 700k on it and is still running strong.


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## Happyjack

"Found a 98 12 valve 3500 dually with 46k original miles. An old couple close to me traded it for a jeep bout 2wks ago. The dealer is asking 9k and that's a steal. "


You should really buy that if you can it's a smoking deal. I just went on autotrader.com and nothing was even close $ wise.


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## mini14

well i have a 99 and an 05, the 99 is a love hate relationship, i put pusher pump, secondary ff and new vp @95k, with a 24 v expect to be putten a new vp on it....get the 12 valve, they should be more reliable as far as p-pump is concerned, and just get yerself a set of injectors and turn up the pump a little, advance the timing....should only take u bout an hour to do injectors, just make sure u get new transfer tubes with the injectors cauz 12valve engines can only be used once..When your vacuum-powersteering pump starts leaking, cauz it will, there is an updated o ring kit for $8.00 to fix it, just make sure u get a kdp kit u can order it from cummins too. the 12v should get better mpg's too. i get 17mps city 21 highway with the 99.


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