I love the Ford 7.3 Power Stoke (and IDI) as much as the next person, but in my eyes, the greatest diesel pickup truck ever built has a Cummins 5.9 under the hood. And not just any Cummins 5.9, a very specific one offered during very specific model years — I’m talking about the 12-valve outfitted with the coveted “P-Pump.” Hook that motor to a stickshift and you have The Holy Grail, which I’m amazed to see on Cars & Bids right now. Seriously, I cannot believe my eyes: this is the one True Grail.
I used to work at Cummins and Chrysler, so maybe I’m a bit biased here, but it’s not like I’m the only one saying the Cummins 12-valve is the greatest consumer-grade diesel engine of all time. That’s pretty well established. In fact, I wrote an entire article on this titled “Here’s Why The Cummins 12-Valve Is One Of The Greatest Truck Engines Of All Time” describing why the Cummins “five nine” is so unstoppable.
Here’s a little proof behind my assertion:
[Cummins’ marketing director David Goggins] went on to say that the 5.9-liter engine actually originally started as a joint venture between the Indiana-based diesel engine company and Case Corporation, which builds tractors and construction equipment.
And indeed, starting in 1984 (well before the 5.9-liter engine ever found itself powering a Dodge Ram), Cummins offered three different variants of the 5.9-liter called the 6B, 6BT (turbocharged) and 6BTA (turbocharged, aftercooled), which served duty in tractors, combines, excavators, road graders, pavement rollers, boats, field sprayers and even school buses.
These are all seriously heavy duty applications. Add that to the fact that these engines were available in dozens of different markets with different climates and work environments (like Russia, China and India), and you can imagine how relatively understressed that Cummins Turbodiesel was once it finally made its way into a Ram pickup in 1989.
And here I describe a bit about the way the engine is built:
But perhaps even more impressive than its factory torque numbers is the engine’s reputation for longevity. Once you start looking at the mechanical bits, you begin to see just how overbuilt the B-Series engine really is. The block and head are cast iron, the crankshaft and connecting rods are forged, the seven main bearings are massive, and like many heavy-duty diesel trucks, the crank and cam are connected by a steel timing gear—not a chain or belt like you’d find in normal cars and trucks. The Holset turbos are also know to last until the end of time.
There’s really not a lot going on with this engine; simplicity, really, is what makes the silky-smooth inline six unkillable. The cam is in the block, actuating pushrods to open and close two valves per cylinder, the geroter-style oil pump is right up front on the accessory drive, there’s no aftertreatment system (just a muffler), and the fuel injection system is purely mechanical.
The key, as with pretty much all things ultra-reliable in the car world, is a reliance on simple mechanical systems. And one of the things that not only gives the Cummins 12-valve its reputation for reliability and mod-ability is the mechanical fuel pump known as the Bosch P-Pump:
In some ways, you can look at the P-Pump as a small engine driven by the main engine’s camshaft. The P-Pump is a fully mechanical pump that controls diesel injection into the engine, requiring no power from the battery. It’s a “dumb’ system, but highly tunable in that, with just some basic wrenching, can be cranked way up for the cheapest, freest horsepower in existence.
Back in November, our Mercedes Streeter wrote “Two Decades Ago, You Could Buy A Dodge Ram With A Manual Transmission And One Of The Greatest Truck Engines Of All Time: Holy Grails.” In this article Mercedes describes the Holy Grail:
Both [the 12-valve and 12-valve]… engines are popular and you’ll find people paying pretty crazy money for a clean second-gen Ram with a 5.9-liter Cummins in it. However, of the two, the 12-valve is the grail. Why? The 24-valve’s Bosch VP44 injection pump is reportedly a failure point and one that can be costly to repair. Apparently, many 24-valve engines were also made with thinner blocks, sometimes resulting in cracking by the freeze plugs, which causes coolant leaks. The engine’s exhaust manifold is also noted to crack.
The 12-valve is generally the more reliable of the two engines with fewer parts and electronics to go wrong. At the same time, tuners have figured out that the 12-valve can accept some frankly silly power numbers. Want 1,000 HP? The 12-valve can handle that! Still, even the 12-valve has a few problems here and there, such as the so-called “killer dowel pin.” This pin helps with aligning the timing cover but can migrate out of place, ending up inside of the engine and causing havoc.
[…]
The grail of the grail seems to be the 1998 Ram 2500 Quad Cab with a 12-valve Cummins and a manual transmission.
Why? 1998 was the first year for the Quad Cab (four-door), but the last months for the 12-valve. Ram owners can tell you that the automatics in these trucks weren’t a strong point. A 1998 Ram with a 12-valve, Quad Cab, and a manual transmission appears to be ridiculously rare nowadays. I found a couple of archived for sale ads, but nothing current.
That “the grail of the grail” link in Mercedes’s story takes us to a discussion on the “Diesel Truck Resource” online messaging boards about why the Dodge Ram — built during only a couple of months in 1998 — is the Holy Grail (a term, you’ll notice, that they used way back in 2005):
And one such grail — built exactly in that narrow timeframe in 1998 when the quad-cab first came out, but the 12-valve hadn’t quite been replaced by the 24-valve — is now up for auction on Cars & Bids. Behold:
It’s rare to see these Grails hit the market, and this one — a sub-65,000 mile example with four-wheel drive, a stickshift, no significant rust, the “killer dowel pin” kit already taken care of, a lovely cloth interior and decent paint on the exterior — is just an absolute marvel.
The current high bid is $23,000. No matter how close we are to a recession, you can bet this is going higher.
Images: Cars & Bids
Geez, I sold a two door five speed a couple years ago for $500. Current owner said it was perfect mechanically, but cosmetics have somewhat more character. I hear that my old truck is a fixture at vintage race events now.
https://dailyturismo.com/hughs-truck-1991-dodge-ram-250-cummins-diesel/
Perhaps the current owner is reading this?
Not even near worthy of the title. Turd of a truck, was decent not great new but far less so now with the falls apart when you look at it interior and trans that failed every 30k. Transfer cases that narily made it past 120k.
I guess check back in ten years and see how my ’95 is doing, huh?
I guess you missed the part where this has the manual transmission. Never heard of a Dodge transfer case failing ever.
Looks like this has the Getrag 5 speed transmission.
Nv4500. Usually solid transmission. However, if it was bogged down repeatedly the 5th gear nut could vibrate loose. Losing access to 5th gear.
Just pulled 2 stumps today with my 1995 Ram 2500 V10 and NV4500. The trans is solid but doesn’t like fast shifts. The manual was the only way to go in trucks of that era, with the V10 you’d get a dana 80 rear with the manual, instead of the dana 70 with the auto. It’s only got 150k miles on it, but apart from the interior falling apart (mostly redone now) it hasn’t had many issues.
Hmm, I guess we missed that by a yeat.
The overdrive is kinda funky, hung off the back of the case like an add-on and not made for heavy use (i.e. use 1:1 for hills). The one gear comes loose and slides back to where it no longer engages but no damage occurs. The fix, a new nut w/ set screws, is a few bucks and 4 hours for a guy in his driveway, or new mainshafts have an upgraded attachment.
Other than that the trans is bulletproof and so is the Dana 80 rear that came with them. A major part about the “Grail” thing is that transmission/rear end combo, the automatics do not hold up at all.
Beautiful truck! I’m curious to see what it sells for.
Now that is a Grail. The ultimate Pappy truck. If someone who lives in a rust-free climate, that thing could be a legit lifetime vehicle.
Oh, pish-posh. The 12V Cummins with a P-pump is only great if one doesn’t care about cold-weather startability (which is pretty bad) and emissions.
Howdy.
Found the coal roller.
Coal rolling potentially clogs up the exhaust system and hampers reliability. Not my idea of a good time.
Now for a global overlander…
But the POWAH!
All 160?
More like 500
https://www.drivingline.com/articles/500hp-on-a-budget-12-valve-cummins-edition/
I don’t modify my engines for power, just longevity. The Original hp rating for the Cummins engine is 160 hp. The Torque is much higher but is wasted on an unladen truck.
Good since the trade off to power is not only (usually) longevity but emissions too.
Clogs up the exhaust system? What exhaust system? It’s a 12v Cummins with no catalytic converter. It’s just the muffler.
Did a quick google check and they had cats starting in 1990 so they can clog.
Older diesels often did not have catalytic converter from the factory. Looks like 1989-1994 12vs had no cat, then 1994-1998 did, and then starting with the 24v in 1998.5 they got rid of them again. So you’re correct that this one has a cat.
Impressive research.
I will always subscribe to longevity over power and durability over creature comforts.
Now this is article “eye-bleach” over that other article.
Well done.
I’ve got essentially that truck plus one better; a long bed that can haul material like I need. It’s proven to be one of the best vehicles I’ve ever owned. The only thing is, I had to put it together from parts. Good Cheap Tow Vehicle – The BangShift.com Forums
That is ungodly clean.
That being said it being a 98 Model year means it’s a no go for me sadly.
Why is 98 a no go? Are you a fellow 1st gen admirer (or owner) like me?
Model year 97 and older diesels are SMOG exempt in most places.
Ah okay I know both Illinois and Indiana diesels only do emissions testing on like 2008 and newer
Lucky ya. I very well may end up moving to California as much as I don’t want to, due to the sorry state of the housing market (every house has to be a monetary investment, so every homeowner doesn’t want housing prices to go down). If things don’t improve in my personal life the only chance of me being a homeowner is in the woods in California :'(
Oh I feel yah I was going to move to VA from Indiana but I just could not justify the mortgage and price of everything out there. I made the mistake of buying a house out there last year and the mortgage is 70% more then my Indiana mortgage because of the prices and interest rates.
Hey, the woods in California are beautiful, but unfortunately not nearly as cheap to buy/live in like they used to be…
California is the most beautiful state in the USA. It’s the management I got a problem with.
Lifelong resident of the Bay Area here, you’re preaching to the choir, my brother!
But to be fair, I know that the same could be and is said just about anywhere, by someone…
Only counties in hoosier land that smog is up in Gary, down in Evansville, and one just outside of it.
Everything else don’t care along as the tags are current
I had thought it was only lake and porter county that needed emissions since they are considered Chicago. I am in one of those two didn’t know Evansville requires it.
My in-laws owned a barebones 91 single cab with the only options being the 12V Cummins, AM/FM radio and 4WD. Best truck they ever had, it helped them build their beach house in the Gulf of California back in the early 90s.
As my FIL was approaching retirement and the truck needed paint, brakes, tires and not having A/C, it wasn’t as livable nor as indispensable as it once was and the beach house needed A/C and roofing work done. He had no idea how much the truck was worth back then (2018) but he knew how much money he was short to get the house work done, so he settled with a local fisherman for $3000.
I still kick myself every once in a while as that was the truck I should’ve purchased instead of owning 2 cars + a project truck that was giving me such a hard time and draining my wallet, LOL…
Damn I paid 7500 for my 92, has broken ac and only a d250 so no 4×4, back in 2019. Shit if I could have gotten a clean 4×4 for 3k I would have fainted. Clean 4x4s were going for well over 10k at that point and pushing closer to 20k or more for nice ones and now it is even worse.
I hear you. To be fair the truck needed to either be towed home or gotten its brakes done on site as it was dangerous to hit hwy speeds with pretty much no brakes and it was located 350 miles south from me in a remote coastal town with no reputable repair shops and only landline and starlink networks, but all things considered it would’ve still been under 5 figures once considering the flatbed rental, re-spray, tires and brakes.
That fisherman has to be the luckiest man in town…
I like it and I am sure the price will hit ludicrous level soon. I would use it as a travel trailer hauler vs a 5th wheel. Keep a battery operated trailer mover in the back and this could be a nice option.
Future article request: 7.3 Powerstroke vs 5.9 Cummins cage match, discussing both engines as opponents
That would be a really fun article especially if go over the changes of the 12v from 89 to 98 and the changes for the 7.3 from 94 to 2003. Also things like how the stick shifts actually had more power and torque then the autos back then which is vastly different from the last 6.7 Cummins that had a stick where the auto actually had more power and torque then the stick.
It is amusing to me that DT spends article after article extolling the virtues of reliable and simple old lumps like the AMC 4.0 and the Cummins 12V (greatest of all time!) but chooses for his daily driver a plug-in hybrid BMW full of the latest electronics and gizmos.
Daily driving a 4.0 Jeep or even a 12V here in LA would be… a bad idea.
Also, I do still own a Jeep J10, a 4.0 ZJ, a 4.0 YJ, a 1954 Willys, a 289 Mustang and on and on.
But I do like that i3S as my daily, I must admit.
Sounds like you need a little 12v in your life (maybe a swap into the J10 haha). I enjoy mine as a daily on ruralish Indiana but yeah no way in hell I would daily one in a city also hard to daily with no A/C but at least doesn’t get to hot here and when it does I drive my FJ.
No offense is meant, just find interesting the contrast between calling an engine the GOAT based mostly on reliability (what other justification could there be when modern diesels far surpass the 12V in efficiency and especially power?) but then going with the antithesis of those virtues for oneself.
It all goes to show there’s no one right way to appreciate cars.
It’s interesting, because as complicated as my i3 is, it’s also rather simple. One could argue that, overall, the i3 is more mechanically simple than even that Cummins 12-valve.
There’s also something to be said for modern comforts. I love my 4.6L Mustang… but if I just need to crush miles, the Maverick is my go-to. Plus, you know, the significant difference in fuel costs.
Does a modern diesel actually pass it more efficiently though? 1st gen 12v’s can get 20-25 highway when kept stockd and depending driving conditions that is. I have said on here before I normally get 21-22 in my near bone stock 1st gen (only has a straight exhaust) and I have a lead foot. Power wise yeah night and day difference from the newer trucks but it is easy to get more of power out of 12v’s since they are mechanical.
A modern HD diesel isn’t going to be more efficient, but one has to remember that they are pushing out literally twice the power.
The modern comparison to a 12V power-wise is a half-ton 3 liter diesel, which really does get much better mileage (30 in some cases) while making similar power.
Which I find a bit odd though I get the new trucks are push out more power and torque but you think they would be as efficient or more then a 30+ year old truck/engine. Seems like everything else got more efficient even the big v8s in muscle cars but for some reason the diesels not so much. Well I guess you can look at things like 4runners and Tacoma’s and those still get crap mileage (my FJ gets a whole 16 on a good day). So I guess a big ole *shrug* hah
Keep in mind that a new Ram is almost 4″ taller than the 1998 vintage, and almost 1500# heavier. They are also orders of magnitude cleaner, and that clean air does not come for free. You literally have to inject diesel into the exhaust stream during a DPF regeneration.
Regeneration can be done without additional fuel. It’s all about what your Exhaust Gas Temperature is. Modern diesels will passively regenerate the DPF (burn off the soot without added fuel) if the exhaust gas temp is high enough. This is the case if the engine is under enough load. Active regeneration – in which extra fuel is added, to be burned in the exhaust stream in order to heat the DPF – is commanded by the ECM if the DPF reaches its soot loading limit when the EGT is not reliably high enough for passive regeneration. One of the problems with driving a 2500/3500 diesel pickup for unloaded commuting is that the engine load is so low that there is no opportunity for passive regen of the DPF. See also: DPF Regeneration: A Comprehensive Guide (snapon.com)
It’s humanities old issue with spending all it’s time helping the middle solution become better and never the strongest/best one which is left to rot.
Diesel engines basically run more efficient the higher the compression ratio is. Since gasoline engines are not as easy to make efficient, we spent the last 50 years improving those because that is the middle solution humanity favors.
Diesel was seen as “strong enough” to shoulder its own weight and received no help. Anytime emissions gains were desired, diesel was made to deal with lower and lower compression ratios, stealing it’s efficiency/thunder.
Gasoline engines got fancy cross-flow cylinder heads, fancy camshaft modifying systems, direct injection fuel systems, hybrid battery systems, and all that to barely *match* what a 1980 mechanical 2v side-flow diesel put out 40 years ago.
If we had instead spent our energy on the strong, diesel would be perfected and even more efficient than it was in 1980 but our priorities were elsewhere. Gasoline got all the love.
Diesel is too “privileged” to get any love. All we do to that category is tear it down and force concessions to the middle-solutions. Which is where we are today.
A 25:1 compression mechanical diesel from 1980 is still more efficient than todays whiz-bang 15:1 compression ratio diesels that lose all the efficiency to appease air police.
That brings up the question to is my 12v Cummins actually better for the environment then modern diesels? Seeing all the rare earths materials that have to go into the emissions systems what is the emissions going into getting those materials? How how the emissions that does into producing DEF and all the bottles that are wasted after pouring it into tanks? It brings back the thing of switch from paper to plastic like yay less trees are cut down but now more oil is produced to create the plastics.
I’m in the same boat as you. I love the mechanical simplicity of my 1972 Super Beetle (which, like the Cummins, has a gear-based timing setup). It’s easy to work on, parts are cheap, etc. But it would not make a good daily. It’s no fun on the highway, it’s only marginally safer than a motorcycle, and of course, no ac in an area with hot summers and high humidity. It’s my “around town” car.
My daily is a 2014 Sportwagen TDI, which, of course, has a very complicated diesel engine. But I’ve heard good things about the longevity of those engines, so I’m willing to take the gamble. It’s literally my idea of a perfect daily, and I intend to hold on to it for a long time.
I think the key is – the old mechanical systems were reliable and simple – but cars have moved on for a reason. We now expect levels of comfort, capability, and durability (not necessarily reliability…) and SAFTEY that these old vehicles simply can’t handle.
A 12v Cummins would not be able to replace my HD truck today – It simply would not be able to handle the workload. Is it more reliable then my current late model HD truck? Probably…but it wont reliably do what I need to do, so is worthless to me. Fun to look at and drive around town maybe though.
I agree which is why I’m usually quite wary of labelling things from the past as the best of all time.
Still, there are certainly vehicles sold now that fit the reliable and simple criteria better than a BMW i3.
Someone who wants the spirit of a 12V Cummins in a city-friendly form factor is probably driving a Mirage for example.
It also has… the same number of valves?
I have no idea what you are doing with your work pickup, but I find it highly unlikely that a 12V Cummins is literally incapable of doing it. Maybe not as fast, but there is very little that a 12v cannot accomplish.
Maybe not the engine, but the rest of the truck is likely not capable of handling it. My 2008 Silverado dually barely matches the payload of comparable single rear wheel trucks made today. From a towing perspecitve, it is not even close; the modern trucks are simple capable of far more.
My current Toyota hybrid may just be the most reliable vehicle I have ever owned. It is a 2014 with about 240k and has needed nothing more than basic routine maintenance.
I’m not sure how much that Toyota data point has to do with a BMW though.
I own a reliable V10, that doesn’t make the E60 M5 reliable.
I’m referring to the overall complexity of ICE drivetrain coupled with an EV system. The Toyota ECVT seems bulletproof and the 2.5L ICE is a fully proven technology. My battery and drive motor are still good, as are the various electrical components needed for daily operation. The rest of the car is just a car. They seem to have figured this tech out.
DT, its almost as if you used to work for Chrysler/DC/FCA at some point in time…
Ever notice how todays pickup trucks & engines sound like 1980’s gay porn film titles?
“Duramax”
“PowerStroke”
“Ram”
“Cummins”
“SuperDuty”
“Titan”
“iForceMax”
Hmmmm….
If by “today’s” you actually mean “from 20-30 years ago”.
Also Cummins has been around for how long?
Good point, that’s not from 20-30 years ago. The company Cummins was started by Clessie Cummins in 1919. Cummins was born in 1888.
Not quite, but nearly as long as porn.
Street you grew up on + name of your favorite engine. That’s your industry name.
Murphree Boxer checking in
I’ve already seen (definitely online and possibly in person…) window stickers that say “anyone can stroke it, but it takes a real man to RAM it” or something very similar.
I want it but I already have a 1st gen cummins and I actually prefer the how the 1st gen looks and the VE pump I prefer over the P as it is better for fuel economy. Though I do wish my truck was 4×4 maybe some day I will convert it or get a clean 4×4 (though prices are stupid now). Still the 12v to me is my preferred diesel over anything else even the 7.3 power stroke. Also did you mean the powerstroke 7.3? As the idi was reliable that is nowhere near sought after or seen as a million mile engine as the 7.3 powerstroke.
Come on David, 6.9>7.3 IDI.
You worked at Cummins?
I think David meant to say the Power Stroke 7.3 as the link is to an older power stroke article Mercedes had wrote. The 7.3 power stroke and 7.3 idi were two completely different engines only shared bore/stroke size.
I sure did. Internship in the summer of 2012. I was the intern in the Advanced Engineering Mechanical Development team.
My job, specifically, was to diagnose why their pinion gear testing rig (called GIRT — Gear in Refrigerant Testing rig) as well as their Gear in Oil Test rig were both failing.
(The issue is that the runout tolerances specified in the engineering drawings was WAY too big, and spinning 50,000 RPM, that’s a huge issue).
And yes, Powerstroke!
Sounds interesting.
I assumed that you were talking about IDIs especially because you then extolled the virtues of a fully mechanical diesel.
To be honest, I like them both! But that article was a Power Stroke article, so I want the link to match the motor. I’m just gonna put in both; I love the cheap parts and simplicity of the IDI.
I had a buddy that had a 6.9 idi was it fast? Hell no but simple and cheap to work on and can pull what you need? Yes it was and yes it did. Power strokes on the other hand yeah no they are a pita to work on at times especially in the 99-03 (I had a 2000) there was no damn room in that engine bay and if you need to change injectors oh yeah they are under the valve covers unlike the 12v right up top and just need to disconnect a fuel rail. Also so much room under the hood 1st gen Cummins it sit in my engine bay all the time when working on it (yay for being small)
Thank you for the insightful comment.
As the previous owner of a 7.3L IDI van and the current owner of a 7.3L PowerStroke van, I have no empathy for your complaints about a lack of room in the engine bay. I may need to upgrade to a 6.0L van so I can appreciate how much room I currently have to do work.
Haha I would love a 7.3 van or Duramax and why a 6.0 may I ask? Also yeah I don’t envy you do you just take the whole body to work on your engine like a semi truck haha