We have a 94 international with this engine. It just don’t seem to have a lot of power to me. Just seems kinda flat when climbing a grade. Even empty I’m not impressed. Has a 9 speed. Other than the fuel filter are there any hidden screens in the fuel system? Before we get too far into it I’d like to eliminate the simple things. Thanks
You got Jakes on that beast? How about boost leaks and air filters? What color is your smoke?
Yes it has Jakes first start up it’s bluish smoke. Other than that don’t smoke much. Air filter is clean. Haven’t checked for boost leaks
To your knowledge, have the Jakes ever been serviced? The solenoids will leak oil over time powering them up without electricity. It's easy to remove them and plug the oil feed for testing purposes.
No sir I don’t know the history of the engine
Does it ever feel like it has a miss? Do you hear any loud rushing noise when under a load? Is this truck new to you?
No miss and no noise really. Just don’t seem like the power is there like I’m thinking it should be. We’ve had it about a year. We don’t put many miles on it. It’s first 9 speed I’ve ever driven. Used to the 13 speed road rangers. It’s been a while since I’ve driven a rig. Our driver says it has plenty power but doesn’t seem like it to me.
What hp is it set at?
I really don’t know. I’ve heard like 475 but really no idea. I’d like to fond out though
Yeah, yer not trying to compare it against a 3406B are ya? The B hits like a sledgehammer when turned up. The electronics of an "E" are more subtle by design to save your driveline.
Truckshop should weigh in on this. I've been outta on highway for almost 20 years. He's current, his knowledge shouldn't be as dusty as mine. Oh, are you feeling the boost build or not. You might have a stuck wastegate. That used to be common.
Can you read the tag on the motor?
Not sure about that. I too have been out of trucking for a while. It was back in 82/83ish when I drove full time. Damm I’m old lol
5EK43244
It left the factory set at 355hp at 1800rpm.
355 it would see a hill in Pennsylvania from Indiana and start slowing down
I'm not a cat guy, but I've strapped quite a few of them on the dyno. That torque starts off idle and pulls all the way through. I don't see 355 as a bad number, for longevity.
Well that would explain it fosho. 355 isn’t much. It does what we need it to do though. How much trouble and money is it to boost it up to 425 or something like that. Just curious thanks for the replies
Glad you guys settled this. But really it's the peak torque that matters. Lot of difference between a 3406E that has 1650 torque and one that's set at 1850 and both are 475 hp.
Horsepower can't be measured, only calculated. The simple formula for imperial units is RPM multiplied by torque (ft lb) divided by a constant (5252). This makes pure horsepower figures fairly meaningless. At 1800 RPM, this particular engine is making 1036 ft lb of torque, which works out to the advertised 355hp. Its peak torque however is a much greater 1450 ft lb but it occurs at only 1200 RPM, which works out at 331hp. Peak hp is 380 at 1600 RPM. If we pull its figures from Cat's database and put them into a spreadsheet we can see by the graph that the HP curve is actually pretty flat.
Then compare it to a nice fruity 3406E marine engine (800HP). The radical torque curve would make for an interesting driving experience in a truck.
One thought from Cmark's chart in post #20 above - don't rev it. It seems to pull far better low down around the 1200-1400 range.
When I used to teach apprentices at the community college I would explain horsepower as the ability to accelerate. Torque is what actually pulled you up the hill. The question I would ask truck drivers who were complaining about low power was were they having to shift into lower gears than they used to when going up the same hill. The other question was how fast were they going when they reached the top of a hill today compared to last month. It used to be that the truck driving instructors taught their students to keep the engine RPM against the governor when pulling hills. When the engine torque and fuel economy became a big deal they changed and wanted students to shift once the engine got below about twelve hundred RPM. It seems to me that the advent of transmissions with fewer gears seemed to become a lot more the norm then.
Thanks for posting that Cmark.
Prime example of torque curve is the old 855/NTC Cummins. On any of those engines if rpm fell below 1700 on a hard pull it was all done. You wanted to start your down shift at 1800 because of lag time on the shift, it come back in at 2100. But for steady pulling rpm 1900 to 1950. People only have a tendency to look at the hp not the torque.
These charts are from a clutch selection guide. Like everyone else has said, the hp #'s don't matter as much as the torque number when loaded up. A 3406e at 335 has a similar torque # to a 400 hp 3406b model. I find my B model doesn't seem snappy up top, but loaded up, it really pulls down lower in the rpms. That's where that big 14l engine shines. The 9 speed trans. vs the 13 means that you can split the top 1/2 of the gears (in general- a old 613 isn't like that). I don't find that a big deal if its just short runs. Out rolling on the highway half splits are kind of nice. I tend to think the rear gear ratio's and tires make more difference than the particular transmission. What's the specs on the truck? Direct or overdrive transmission, what gears in the rear end and what size tires? And then what kind of a load/ gross weight are you hauling?
It seems as though torque is a subject that carries a bit of mystique. Ask an average person to define exactly what it is - and its relationship to horsepower - and often the room falls suddenly silent. Sometimes the mark of a true genius is his ability to explain a tricky subject in a way we can all understand. The late John Robinson - he of PB Magazine fame - was, in my humble opinion, a genius. Here's how he defined the difference between torque and horsepower; "Suppose some miscreant were to chuck a 20 pound labrador off a cliff - only a puppy, really. You scramble down the cliff, discover the animal is fine, affix a rope to its collar then cast about for ways and means of raising it to the top of the cliff. Any engine making 20 ft/lb of torque, and attached to a 1ft radius winch drum, would be able to lift the labrador. An engine which gave this torque at 4,000rpm would be able to lift the dog twice as fast as one that did the business at 2,000rpm. And that's the difference between torque and horsepower. The 4,000rpm engine would get your dog back twice as quickly - and be twice as powerful - as the 2,000rpm engine."
The one thing not mentioned though is the EGT's when really pulled down to base rpm and held there, It would surprise a few.
That's shocking, my 3406B pulls incredibly well grossing around 90,000lbs with 13 speed, I figured it had more torque then that. It pulls pretty close to as well as my old truck that had the maxxforce 15 500hp and 1850 torque. Assuming the OP is in a straight tandem application grossing around 50,000lbs it shouldn't be lacking power at all, unless the engine is tired.
Plus the idea that a 3408 was dynamite-look at the torque specs above compared to the 3406. Even with two more cylinders to wear out the 3408 wasn't all that productive.
Just for kicks here's a comparison. This is between a 3406B 425 and a 3408 450. (It's the closest match I can find.)
We dont have the the b series anymore that thing was set at 425 and you could burn it down if you didn't keep an eye on things when hitting a grade but the e series has a much smoother pull my e series is set up at 400 it pulls plenty good sometimes I want more but hot motors in our climate just sucks I drove a c15 that was supposedly set at 600 now that thing was almost scary not sure if it was really at 600 but it could probably pretzel a frame rail I would want more than 355 cause we had a 3306 at 325 and that thing was a wimp a freeway ramp would make it whine
Years ago I would hear {why won't my ntc 400 keep up with a cat b 400?]----apples and oranges.
I have always said " It costs alot of money to be the first one to the top of the hill"
My only complaint about mine is top speed, it's wound out around low 50's mph guesstimating the speedo isn't that accurate. Unless it's a really steep grade it'll hold 8, and haven't had one it wouldn't hold 7th on. For city moves which is 95% of my stuff though it gets there just as fast as a new truck would. The best part I like is the cost, about 1/15 the cost of a new one.
Am I the only one here who used to move D8s with a 237 hp Mack?
Be careful mitch you might date yourself with statements like that would make a guy think you been around quite a little while My grandpa got tired of pulling d8s with a 270 cummins way back when so he bought a truck with a 3408 it lasted about a year before the frame broke is how the story goes but that was a huge step up from the chain drive diamond t that he started with
Oh there were a bunch of D8's moved with small power. The B71 below was used to move a A14 also below, 220 Cummins with a three stick 9 speed over gear transmission. I moved a 69 kw with a D8H to the top of Rye Grass summit with a 63 KW COE tow truck powered by a 335 and a 4X4. The 69 blew the rag clutch, I was on the old road between Ellensburg and Vantage, the grade is 11 miles long it was half way up so it was about five miles of 5 to 6%.
The world was a lot more patient back in those days. Those are pretty good looking toe nails on that old 8.
Yes John the world was a lot more patient back then, where did we go to hell-at what junction did that happen. I guess that's a different discussion.