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12 valve vs 24 valve

53K views 28 replies 14 participants last post by  sstockton 
#1 ·
what would the benefits be for 12 valve vs 24 , i'm looking at buying a 94 - 2002 dodge diesel for work and pulling my enclosed trailer 6000 # daily . i don't no much about dodges . i just know with my 2008 powerstroke the mileage of approx 6-7.5 mpg is killing me when i drive approx 150 miles per day .
what are auto tranny differeces if any which has the stronger setup ??

i'm looking at extra cab 2500 4x4 mostly .

any input would be great
thank chris
 
#2 ·
well if you're lookin for an extra cab you're more likely to find a 24v. In the 12v the modifications you make are mechanical, so if you have the tools and the time you can do it yourse;f for pretty cheap, you have great fueling with the p-pump but the iming's pretty fixed, it gets great mpg and it'll last forever, but you should probably avoid an auto, or at least be ready to fix it, they're pretty rough. The kdp, killer dowel pin, it aligns the timing case to the block and can wiggle its way loose after a while and do anything from nothing to screwing up your timing, well, everything, but it can be prevented

for the 24v's they have an electronic injection pump, it's kind of an issue, becuase the factory lift pump sucked, it would die and leave the ip to suck the fuel ot alone, the vp-44 not being built for that, it'll fail a bit after that. but if you get an aftermarket lp you can prevent forest fires, if you know wha i mean, with the 24v you can just hook up a programmer and get some pretty impresive power gains, but the auto's still are pretty rough, there are 53 blocks that were cast weak, but a small percentage were an issue and it only becomes a real concern at higher hp uses

overall the mpg increase owuld be huge, plus you ge the ease of dealing with the cummins, the auto' like i said are an issue but there are ways around it, if you take whatever preventative merasures you need, then these engines will last forever and put out great power for the price, oh and no emissions bs, good luck man
 
#3 ·
Yeah, I have to agree, that the auto's aren't that strong. If you are buying a truck with any kind of miles on it, or going to turn the power up at all, you will need to build up the auto to make it stronger in any application. As far as the trucks are concerned from a bone stock stand point, they are both strong but have some weak points. 12v, KDP which is an easy enough fix. And like mentioned above with the 24v is the Lift pump and injection pump. However, contrary to popular belief, just throwing a better lift pump on won't save your Injection pump. Its going to die.

As for milage, I didn't notice a huge difference between my 12 and 24v, but my 24v is 4x4 single rear wheel and the 12v was a 2wd dually. Both got/get around 17 in town, 19-21 on the highway, up to 23 though on occasion. And towing 6k, probably still 15-16 in town and 16-17ish on the highway. However it really comes down to driver. Hope this helps a little. IMO they are both great trucks. The 98 and up has a nicer interior with cup holders that work, if you're spending that much time in your truck you may want to take the interior into consideration.
Sean
 
#4 ·
sstockton said:
interior with cup holders that work, if you're spending that much time in your truck you may want to take the interior into consideration.
Sean
It sounds funny but its true! LOL That's what I like about my Auto it the cup holders. We aren't the only people that say this. If I ever convert my 6speed manual to a automatic that is the first thing I'm going to look into is putting those cup holders in!:Thumbup:

My opinion on 24v vs 12v is get a 24v and plan on putting a P7100 on and call it day. A 24 Valve with a P7100 is known to me as the "Holy Grail"

(P7100 is the Injection pump on the 12 valves)
 
#5 ·
the Cup holders in the 94-97's suck, The bottom peice breaks off ( like mine) then its useless..! the only thing is will hold is a med-lg cup from mc donalds LOL LOL Altho I like the seats better in the 94-97's I think there a little softer on the bum. The p-pump is one nasty biotch but if you get the lift pump fixed on the 24v they can lay down some power.. I wouldnt mind having one.. IMO I think the 24v sounds better then the 12v..
 
#6 ·
chrislancaster said:
what would the benefits be for 12 valve vs 24 , i'm looking at buying a 94 - 2002 dodge diesel for work and pulling my enclosed trailer 6000 # daily . i don't no much about dodges . i just know with my 2008 powerstroke the mileage of approx 6-7.5 mpg is killing me when i drive approx 150 miles per day .
what are auto tranny differeces if any which has the stronger setup ??

i'm looking at extra cab 2500 4x4 mostly .

any input would be great
thank chris
not trying to hi-jack your thread but 6-7.5mpg towing *only* 6,000 pounds is quite horrible, is there a reason behind that? :shrug:

I may need to go and lurk around the Powerstroke side of the house and see whats up with the fuel mileage on the 6.4's
 
#8 ·
All i got to say is its a cummins nothin else!!!:smoke :bow: LOL

i also agree with the cup holder situation haha
 
#9 ·
The bottom never broke out of my 12v cup holders. But the first time I had a fresh cup of hot coffee go all over my foot getting on the freeway, I knew I'd have to get something better.

As for the seats, I like my 24v seats better personally. IMO Its all about a 98 12v. They are awesome trucks, Or a p-pumped 24v. Really thats the only part of the 12v I like more. But that would be enough to make me consider one.
Sean
 
#11 ·
sstockton said:
The bottom never broke out of my 12v cup holders. But the first time I had a fresh cup of hot coffee go all over my foot getting on the freeway, I knew I'd have to get something better.

As for the seats, I like my 24v seats better personally. IMO Its all about a 98 12v. They are awesome trucks, Or a p-pumped 24v. Really thats the only part of the 12v I like more. But that would be enough to make me consider one.
Sean
I think you might agree with this one on the 12valves.....

The 12 Valves have another "mod friendly" attribute......

The 12 valves have the injectors going into the exhaust side freeing up space on the intake manifold so on the 12 valves it's easier to address the ackword intake. Vs. the 24 valves where it's alot harder being on the intake side and I haven't actually seen it addressed.




Something I'm planning on taking on the years to come when my shop gets built. :grd
 
#13 ·
sstockton said:
The bottom never broke out of my 12v cup holders. But the first time I had a fresh cup of hot coffee go all over my foot getting on the freeway, I knew I'd have to get something better.

As for the seats, I like my 24v seats better personally. IMO Its all about a 98 12v. They are awesome trucks, Or a p-pumped 24v. Really thats the only part of the 12v I like more. But that would be enough to make me consider one.
Sean
Thats right :Thumbup: The 98 and ups had a nice interior. And the quad cab option wasn't available untill 98, the earlier trucks were just extended cabs w/ only two doors.

But other then that it all comes down to if you like programmers or turning wrenches and making the adjustments yourself.
 
#15 ·
Anyone had any experance with the P7100 conversion kits? As far as making power, both pumps are good enough for me. (I'm lame, I know)

But the VP44 just has weak spots as far as durability. The P7100 was put on Mack trucks with very little problems. Renault had a version of the VP44, on a 4 cylinder Diesel that still led to problems. I believe this is the pic of that beast.

 
#16 ·
If you are looking for adjustable power on the fly and elctronics go 24v but if you want raw all out performance and decent fuel milage and not hardly any elecronics go 12v cause you can make power much easier and cheaper
 
#17 ·
cedardiesel said:
If you are looking for adjustable power on the fly and elctronics go 24v but if you want raw all out performance and decent fuel milage and not hardly any elecronics go 12v cause you can make power much easier and cheaper

I agree with that statement with the exception of the mileage part. I don't know any 12v that are pushing 30MPG. With a 24v 2wd and the right stuff it's a givin on flat ground @ 45MPH. JPonder's 4wd does it. I don't know if mine will givin it doesn't have CAD. But I promise it would dropped in a 2wd. I've seen 20MPG on almost every tank so far. almost.
 
#18 ·
how much are you looking into spending? Are you going to be keeping your current truck too? The cost of the truck doesn't really cover the better mileage it will get unless your looking at not using your current truck for work and want a work truck.
 
#19 ·
If I had to do it all over I'd be looking for a 12v, 1998 4 door truck (rare to me any how..) the 24v's are nice and will make power but your paying more for it and you better have at least some faith in electronics, knock on wood I trust mine so far. If money isn't an issue buy a 24v and p-pump it ;) . Good luck !! -Ethan
 
#23 ·
01quadcab said:
how much are you looking into spending? Are you going to be keeping your current truck too? The cost of the truck doesn't really cover the better mileage it will get unless your looking at not using your current truck for work and want a work truck.


I WILL PARK THE 6.4 FOR NOW I'M IN THE MIDDLE OF BUYING NEW HOUSE SO I DON'T WANT MESS WITH MY CREDIT SCORES .

IN A FEW MONTHS A MAY TRADE IT IN ON A NEW DODGE AND KEEP THE OTHER FOR WORK I THINK I FOUND THE TRUCK 98.5 2500 DIESEL 4X4 EXTRA CAB WITH 5 SPEED TRANS.

I HOPING THAT THIS NEW TRUCK WILL CUT MY 1500-2000$$ FUEL BILL IN HALF OR BETTER.

THANKS FOR ALL THE INPUT EVERYONE:smoke
 
#24 ·
blackpsd said:
not trying to hi-jack your thread but 6-7.5mpg towing *only* 6,000 pounds is quite horrible, is there a reason behind that? :shrug:

I may need to go and lurk around the Powerstroke side of the house and see whats up with the fuel mileage on the 6.4's

I'M NOT SURE WHATS UP , HAD IT IN TO THE DEALER A FEW WEEKS BACK THEY REPLACE RADIATOR , STEERING BOX, THERMOSTAT AND HOUSING AND TRUCK WILL STILL BEARLY COME A NEEDLE PAST COLD AND ALL FLASHES WHERE UP TO DATE

I AHVE GOTTEN AS LITTLE AS 4.9 MPG HAND CALCULATED PULLING APPROX13,000 LBS
 
#25 ·
View attachment 14497 HERE IS LIST FROM ADD WHAT DO YOU GUYS THINK I MIGHT GO PICK IT UP WED MORNING !!



1998.5 / 1999 2500 Ram Quad cab cummins 4x4 - --------------------------------------------------------------------------------


It is a 1998 but a late one, same as a 99, 24 valve cummins, 4 doors, 5 spd with ac, cc, pw, pdl, all the reg stuff. 15-21 mpg city highway, 13 twoing

the extras

Engine
Pa-Brake exhaust brake
4" SS Magnaflow exhaust
Edge juice W/attitude 400 horse- 850lb-ft torque
Air-aid intake
new high pro injection pump from Oregon fuel inj(2200 dollars)installed @dealer
New pick up pump from cummins and aux pump from oregon fuel inj runs 22 psi

drivetrain
Air bags(cut inner fenders and hence the gap in rear)
new power steering box and pump
new disc brakes,pads and calipers
new mooge ball joints
new clutch by South bend(1400 dollars)
new 37 12.50 r17 cooper dicovery MTs
new tranfercase from dodge
all synthetic oils

Extras
front and rear tow packages
rear tow bar in bed with lights
ss nerf bars
Mickey t's 17" wheels
spray in bed liner
VERY LOUD air horns

int-grey cloth
Poineer 450 dollar sterio with blue tooth and complete i-pod controls in deck-never pull your i-pod out of your glove box
JBL speakers
two 10" subs under rear seat in custom box

i'm sure i've forgotten somethin so call me with any Q's

148k. the only thing that i can find that dose not work is the heated mirrors.

i'm selling because i'm getting a company truck(another cummins lucky me!)
 

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#26 ·
Sounds pretty good. Whats he asking for it? Also, don't expect 400hp if all he has is the Juice with/a and an exhaust and intake. I'd say consider yourself lucky if it breaks 275 at the wheels. Even with a bigger injection pump on there, the best it will do without injectors is low 300's IMO. But still sounds like a nice truck, and I bet you can do all right on fuel economy with it.
Sean
 
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