Irrelevant for a 325hp 560lb-ft 6.0L. Yes I'm sure they are stronger but if the 6.0's can handle the torque, why make them bigger & heavier? It all adds up to inefficiency and losses. Bigger doesn't necessarily mean better.

 

yeah there are a bunch of guys over 500hp. why?

 

For the stock configuration I'm sure the 6.0L rods are correctly designed. It does not make sense to overdesign and consequently burden every engine made with the cost. For the handful of guys that want over 500hp, they may need to upgrade their rods and incur the cost. I don't think I should be paying for it.

 

You are right. But who says the 6.0L CAN handle the torque? Heck, almost every thread in the 6.0L forum is complaining about what junk the 6.0L is so far...who knows if it'll even make it to 100K miles?

5 years from now it might be a different story....but in 2003 Cummins is the only way to go for a diesel pickup. Period.

 

Lol, I have a funny feeling that Navistar designed the rods right and I also suspect there will be many, many engines that make it over 100K. If not, I think Ford will be out of business .
BTW, I'll guarantee you the one I buy will get over 100K & probably over 200K! However, I'm not knocking the Cummins since I have 218K on mine. Too bad it's in a Dodge .

 

Im still partial towards my old turbo diesel IH Scout LoL!

 

For a bit of a revelation, International makes a decent engine made to run a long time at LOWER power in agricultural applications - THEN Ford takes them, BOOSTS the power to make them competitive, and turns them loose on the public...

By contrast, Dodge takes a commercial grade, heavier duty/power engine, then DEtunes it for the intended purpose, and turns it loose... NOW, which do you REALLY think is the best strategy, taking a powerplant engineered for LOWER output, and hopping it up for the truck, or one that was designed for lots MORE power than you actually intend to use? Which will have the greater safety factor, durability and reliability built in - and price really doesn't enter in, since the Dodges typically sell for LESS than Fords...

As to commonly used power by the crazier Dodge owners, 450-500 HP and 1500+ ft lbs of power to the rear wheels is pretty common - and MANY Dodges will outrun Corvettes in the quarter mile. AT the Dodge group May Madness in Las Vegas a couple of weeks ago, the top Dodge dynoed 764 HP - the next one was a paltry 700 HP - both were DRIVEN to the meet - one from Heber Utah... Both are daily drivers, not trailer queens...

There WAS a Ford there that did a decent 560 hp or so... But he had gotten tired of blowing up Navistar V8's, had yanked the last blown one, and installed a cummins in the truck, and THAT was what he dynoed with... The Fords do fine, as long as you don't try to push them too far, too long in the HP race - the Cummins, on the other hand lives quite well and long with pretty radical power increases - yeah, those stout internal ARE a neat thing to have!

 

I won't be disappointed in my Navistar because it will only do 325hp & 560lb-ft of torque and I won't buy the Dodge because the Cummins "can" put out unGodly amounts of power with stock internals if modified .

 

I congratulate you on EXCELLENT, GOOD sense!

It's FAR more reasonable and logical to accept and enjoy your truck for what it IS, and what YOU reasonably want to do with it, than get involved in pointless, baseless arguments as to what you THINK or falsely represent your stuff to be capable of - The Ford is an EXCELLENT work vehicle, fully capable any reasonable task within it's rating - USE it that way, and barring unfortunate problems, it will probably outlast you or your desire to keep it any longer in favor of something newer!

It's the guys who swear their trucks will leap over tall buildings, be faster than a speeding bullet and more powerful than a locomotive - and similar feats that *I* get amused by...

My truck has good, and BAD points...

So do Fords
So do GM's

Anyone thinking or claiming otherwise, is only kidding themselves!

 

Boy, sure hope not, lol.
Quite honestly, the worse thing about a Dodge is the Ms. Piggy front end. Therefore you got nothing to worry about either.

 

I have heard that a few times and wander what I do right that makes my front end last so long. In 130k I have replaced the tie rod ends one time. WHY? because my dad was pulling a trailer through the field and hit a hole and bent the stock one plus broke a balljoint. Even all the 4-wheeling and hauling I do I have not had any problems. Every time i change the oil I grease them. Is it that hard to Greas a ball/tierod end? do that and they will last forever.

 

Hi Gary,

There is another important factor dictating why Cummins' engineers designed the bottom end of their B-series 5.9 litre I6 diesel engine extra sturdily. You are correct when you indicate the strength of the bottom end is needed when the engine is pushed with the need for increased power. In mobile home recreation vehicles that same 5.9 B-series is producing 660 ft-lbs of torque. When an engine has to move large weights up inclines or over soft ground it is a brutal force against the bottom end of a slow turning engine. That is why an operator has to monitor the pyrometer reading of the temperature in the turbo-charger. The engine is laboring and the temperature is increasing to the point where it could destroy the top end of the engine. When the temperature increases to a certain level the driver needs to then down shift to ease up the load demand on the engine so the pyrometer reading goes down.

In the new Dodge pickup trucks the high output Cummins is producing 555 ft-lbs of torgue as early as 1400 rpms. The long stroke of the 5.9 sets the engine up as being able to do some serious twisting of the crankshaft at low engine speeds. That engine is a stump puller, an actual truck engine. The power curves available at Cummins website tell the story. When an engine turns faster it produces inertia at the flywheel and the vehicle has some momentum to help the engine strain against the dead weight load. Thus an engine like the Duramax and PSD V8 engines do not develop their maximum torque until 1800 or 2000 rpms when the vehicle and load have some velocity in them.
If the V8 engines developed maximum torque at low engine speeds it could destroy their lighter built bottom ends.

On a power curve graph the Duramax and 6.0 PSD are capable of producing approximately 300 ft-lbs at 800 rpm. The standard output Cummins produces about 370 ft-lbs and the high output engine prduces about 385 ft-lbs at 800 rpm. Those low rpm counter forces on the engine are brutal punishment. The V8 configuration does not practically allow its bottom end to be as heavily built as the bottom end in an I6 configuration; therefore, the computer has to keep the max torgue from happening until the engine speed is higher or the V8 could be destroyed from the counter force on the bottom end. In a V8 they shorten the stroke because they cannot make use of maximum low engine speed torque. The shorter stroke lets the engine rev higher than a long stroke engine.

Cummins had to strengthen and provide improved cooling for the B-series pistons to accomodate the high output forces. Cummins knows how heavy the B-series has to be built to do serious work not to be use as a runabout.

 

so basicly what you're saying is that the Cummins is a better engine than the Powerstroke?

Forrest

 

F.Y. I like the way you think but I must point out again that in the medium duty applications the vt365 is putting out torque peak at 1400 rpm. The engine is fully capable of it. In the medium duty application it is also making 340 lb ft for clutch engangement torque, 800 rpm. I think clutch engagement torque for the 5.9 is advertised at 350 lb ft. Higher but only slightly. I cant seem to find the link right now but Im sure thats what I read. The Isb was rated at peak torque at 1600 rpms for years. The 03 7.3 is also rated at peak torque at 1600 rpm. Lugging an engine is what I believe you were talking about with incredible amounts of load on the bearings and high egts. Cummins does not recommend lugging because engine damage can happen in as little as 30 seconds. This applies to all makes. Can you point me to any advertised numbers which may be different from what Ive stated? I like to be accurate.
So is that why all I-6s are stroked? Better ability to handle the forces of low end torque. Stroking increases the loads from low end torque. The I configuration allows for a better attack angle on the crank making more torque. They usually spin slower making for less hp. The V has more balance built in and allow for high rpm hp. Making for a quicker motor. I think gm shot themselves in the foot by allowing for such a short stroke. It makes the truck very fast but lousy when it comes to towing big. I think they were more interested in HP numbers than building a good tow engine. It seems like this may be true of the 6.0. Except that the base is a great tow engine and they made it into a racer. Putting the 6 speed owners in a bind while they wait for the torque to kick in. Even with that marvel of turbocharging technology.

They say that the 12v fueled incredibly hard off the bottom.

For the record. Maddog has a Fummins and he laid down 690 on #2 alone. He has also ran a sub 12 second quarter mile in this one ton crewcab 4x4 truck.

 

L.H., if you look at the power curves from Cummins for the 5.9 B-series as used in Dodge trucks it will show that the engine is developing the maximum 555 ft-lbs of torque all the way from 1400 rpm to 2800 rpm and then drops off only very slightly out to 2900 rpm. After 2900 rpm it drops off quicker. The maximum torque in both the standard output and the high output Cummins is not just available at the initial 1400 rpms, but extends out further. Now, it is a different story with the PSD and Duramax. Those V8 engines develop their maximum torque only at 2200 rpm (PSD 6.0) and 1800 rpm (Duramax). On either side of that particular maximum torque producing rpm the torque is always somewhat less than maximum and decreasing the further away from that particular rpm. I figure Cummins should list the high output 5.9 B-series as producing maximum torque at 1400 to 2800 rpm inclusive. I can not point you to any advertised numbers because I only estimate what I can determine from reading the torque line drawn on a power curve graph. The 7.3 PSD possibly had longer stroke than the 6.0 PSD?? and therefore produced its maximum torque at 1600 rpm. How that V8 could stand the forces of the torque on its bottom end is not fully understood by me.

When trying to figure out what gives a diesel engine with a long stroke the ability to develop torque at low engine speed I think of a simple lever system and its mechanical advantage. The longer the stroke the longer the throws on the crankshaft must be to accomodate that particular stroke in a reciprocating engine. Now, the longer the crankshaft throws the longer the lever action (length) from the fulcrum (crankshaft main bearing journals) to the crankshaft connecting rod journals (weight). Working an engine at low engine rpms is not lugging the engine if it is configured for the stresses. Cummins inline six cylinder diesel engines are built to be stump pullers. Nevertheless, you still have to watch the pyrometer guage reading to see that the engine turbo-charger temperature does not climb too high. I would not feel right in working the 5.9 continuously under 1200 rpms. I 6 engines have a longer stroke to be able to produce high torque at low engine speeds because the configuration of the block skirt is sturdy to stand the strain when supporting the crankshaft main bearings. The heavier crankshaft is better supported by main bearings and the connecting rods are bigger with only one rod head on each crankshaft rod journal. No wonder the Cummins engine weighs more that the PSD or Duramax engines.


The horse power rating really is of no relevance for a low speed engine. It is torque values that determine the work that can be accomplished. The force the engine can exert on the crankshaft does all the work to move a dead weight load. When an engine is turning upwards of 3000 rpm the intertia in the flywheel and physical velocity momentum of the load weight helps keep things going. That is why horse power ratings are higher at increased engine speeds. More work can be done if the combustion chamber pressure, engine parts inertia and centrifugal force and load momentum from vehicle velocity are all directed to a common task of moving the load.

When I think of a V8 being able to turn at higher engine speeds I visualize the increased centrifugal force on the connecting rod heads on crankshafts with long throws in an inline engine producing forces and vibrations trying to break that rotating mass out of the bock's skirt. On the other hand, I visualize the short stroke mass rotating nearer the center of the crankshaft and producing less centrifugal force. A V8 can not be beat as a drag racing engine because higher engine speed does not produce the severe forces and vibrations on its bottom end. When the bore and stroke are nearly the same or the stroke is less than the bore it is best as a racing engine.

I drove a GMC tandem dump truck powered by a Caterpillar V8 engine in front of a 15 speed Eaton Fuller transmission. Even in low range and first gear the diesel engine would stall if the slow moving truck wheels encountered some serious resistance. I would have to put the transmission in first gear in deep reduction to get moving. The V8 engine did not have the low end torque like the other inline engines that could power their way out of a similar situation in low gear in low range. With the same differential gearing the V8 engines could produce a higher road speed for the vehicle than the inline engines with the same gearing. The inline engines' fuel was governed at lower engine speeds than the V8 engines. If I wanted a work engine in a pickup truck I would by a Dodge Diesel and if I wanted a drag racing pickup I would be inclined to purchase a Dodge with a hemi gasoline engine.