Cummins powered Big Rigs

[HoleshotHolset]

IF I were in the market for a class-8 truck with a Cummins engine (of course... ) which engine should I look for and which ones should I avoid?? (Keep in mind I'm looking at used trucks in the early to mid '90s vintage... )



I have found a few good deals on Frieghtliners/etc. with the N14... but those are electronic and scare me a bit. I'm looking for a really stout engine that I can crank the poop out of like the P7100 in my 12-V.



I figured I'd skip right over the C8. 3L and go to the big dawgs.



Matt - always in the mood for a little diesel in my life.

 

[Snow man]

Go straight to the Signature 600,it is one strong engine,with an even stronger engine brake. I have afriend with one,he loves it so far.

 

[HoleshotHolset]

oops, I should have put the words "previously owned" into my question..... I can't afford a Signature 600, that I know...



Matt

 

[JHansen]

This may offend some but....

I'd go 3406 Cat..... B series produced from 1984 (?) up until somewhere around '92 when they went to the C series. I think the C's are governed to 1900 where the B's went to 2100-but I could be wrong. All A's and B's were mechanical, C's could be either mechanical or electronic, and E's were all electronic. I jumped right from B to E when the boss upgraded my truck. We had A's, B's and E's in the fleet-none of them bad engines... .



I have a clipping from a truck magazine from a place in Buffalo NY that claimed to be able to wring 800 hp out of the A's, B's or C's







Cat stuff ain't cheap to rebuild-but IMO they last longer than a Cummins. Know that up here at least in the past Cat stood behind their warranty better than Cummins-if you're looking for a used one that part wouldn't really make any difference.



Maybe the yellow-paint-brainwashing has taken too much of a toll on me but if I'd have had a choice for power in my Ram (like a Class 8) I'd have still gone for the gold! IMHO, YMMV, and all the other disclaimers apply...



Jason

 

[FFutch]

N-14 or Big cam 3

N-14s are good motors for the most part,but there's not a whole lot you can do with them as far as pump mods. All electronic. Only has a mechanical lift pumps on them. Some of the early N-14s were mechanical s. t. c. (step timing control),stay away from these. 444s are o. k. But You can probally get a Big Cam 3 for cheap and there's a place in Pittsburgh(Diesel injection of pittsburgh)that has info. on Bombing the big dogs. Cummins does have e. c. m. uprates for N-14s but it ain't cheap. As far as B. C. 3 pumps there's only so much fuel you can crank on them with the throttle shaft and buttons before you start blowing big time black smoke. Injector lobes were a weak link also if you put too much fuel on them. I did notice that Cummins did improve the replacement camshafts that I was putting in(and I did a lot of them)so hopefully that problem is resolved. Of course not going to find a big cam in anything after 92 or 93. Doug

 

[FFutch]

oh yeah

Yella motors are o. k. too Like Jason said they do cost a bit more to fix when they break, especially the pump. Stay well clear of P. E. E. C. motors (Cats first attempt at electronics )they were junk. But the old b-models were A-O. K. Doug

 

[Champane Flight]

4-1/4

I would go 425 Cat too. I have a personal freind who sent his back east for a high performance rebuild. Putting 800 to the ground. He did have problems with heat for awhile,but with some pump tweaking it is doing fine now.



I think the 425 Cat is like the 5. 9 Cummins VERY BOMBible!

 

[FFutch]

Phords

Stay away from LTL-9000s too,If you're going to crank up the fuel. Typical Phord design,the cooling system(i. e. radiator)will not take much more than stock before it starts overheating . Plus they're a p. i. t. a. to work on . Doug

 

[Briar Hopper]

Why not call Bruce Mallinson at Diesel Injection of Pittsburgh, and get his opinion? He can answer all your questions. He's definitely an original, and knows his stuff.

 

[Ray Torresdal]

N14

I don't know how much "poop" you require, but the N14 isn't a bad horse. I've been helping a friend, driving an older N14 with 625,000 +, and it has not had so much as an injector to date. The good news is that a truck in the vintage you are talking about will be cheaper than a new pickup! I owned CAT when I was young, and I'll never bad mouth them, either. They may be more expensive to overhaul, but they can run a looooong time if taken care of. I don't know anything about the older Volvo engines, but just talked to a buddy yesterday who has gone from Pete w/Cat to a new Volvo, and he is thrilled with it. Good luck! Ray

 

[TPyle]

What are you planning to do with the truck. If you are going to try and make a living or even make SOME money with the truck I would recommend looking at the overall drive line instead of just the engine. 800hp is a great novelty and no doubt looks impressive in these posts but not very practical. Clutches, Ujoints, axles, tires(remember tires are what puts all that power to the ground) are very expensive to replace when damaged by over powering them. If you insist on a Cummins an N14 can be rerated to 525hp @ 1850pt. If the truck is older than 2 years and the engine family can be rerated this is a no cost from Cummins procedure. All you would have to pay is about an hour for a shop to do this. Shy away from 18 spds. as they have smaller bearings and shift forks. 13s are the way to go as are 10s (15s are outdated). A 3406E Cat with a 435hp can be rerated after 2 years at no charge also (other than shop time). Get the most for your money because trucks are real cheap now. If you are really serious PM me and I would be glad to help you out!

 

[kcjayco]

The N14 is a good motor. I have seen some with 1 million miles and still going strong. Cat is good too. But upgrades can be expensive. The increase in power can only be made by computer changes within a certain parameter, then some mechanical changes have to made ie, camshaft, turbo and injectors. Check the rating on transmission too. Look at the torque output on any engine as well as HP. Some engines will be 475HP but maybe 1650-1750 lb. ft. of torque or 500HP and less torque, maybe 1450-1650. It depends on what is programed into the computer. Also make sure you have the customer password, if not and it has one you cannot make changes and the ECU will have to be reflashed which is expensive, normally around $750. 00. Just some thoughts. Have the dealer you buy from check the warranty record on the truck, engine and drivetrain and see what problems were repaired under warranty. An OEM truck dealer can see the warranty on the truck. Eaton or Rockwell can tell you the repair history on transmission and of course any authorized Cat, Cummins or Detroit dealer can give the repair history on the engine. Just some thoughts to save problems later. Of course the engines I refered to are electronic controlled. Mechanical are quite different. In my opinion I would look for an electronic engine, for the ease of uprating or changing parameters, ie cruise control settings, top speed and many other things that can be set for customer needs. But look around and find what suites your needs and price. There are some trucks right now in the 97-99 vintage going for $25k-40k.

 

[FFutch]

Drive train

Yeah I agree with you about drive train issues. I used to work at a K. W. dealer and when we had a trans. ,clutch ,or rearend failure the first thing Eaton-Fuller wanted was an engine H. p. and torque setting printout. If the truck had been turned up beyond max. drive train specs. bye-bye warranty . They had a hard time keeping up with Cat and Cummins horsepower wars anyway. TPyle can you get anything but an 18 speed behind the highest h. p models now?I work for the power co. now so I've been out of the loop for over a year now. I've heard Cat and Cummins have up to 700 h. p. ,but no drivetrain yet. Doug

 

[TPyle]

If the engine is out of its original warranty usually, 2yrs/200,000 miles, it can be rerated by an authorized Cat or Cummins dealer at no charge. Of couse the dealer will charge shop time to do the rerate. The $750. 00 charge only applies to engines that are under the original/base warranty. True with Cat you have to check the engine sn to see what it can be rerated to through reflashing only. Cummins you have to check the CPL number. Detroit charges $500 to reflash no matter what the warranty status is.

 

[TPyle]

Doug



The 18 speed is the only trans to go behind the C16 600 Cat or ISX 600 Cummins. It is a RTLO20918B. Rated for 2050 ft-lb input torque. The 550 Cats and 525 Cummins both rated at 1850 pt can use an RTLO18918B 18 spd, RTLO18913A 13 spd, and an FRO18210C 10 spd. The 600 engines haven't been as popular due to drive tire wear.

 

[Archive]

Great posts TPyle. (IMHO, Skip the L-10 & M-11's too. N-14 Period. )

 

[HoleshotHolset]

Believe it or not (and I can just smell the flames now... . ) I just want to own a class-8 truck for novelty purposes. I don't really plan on towing coast to coast for a living, but it may have to tow a car trailer or if I'm nice, I may help out my buddy that has a few class-8's and hauls rocks/etc.



I realize how much these things cost to fix, but the purchase price of the trucks that I have found is REALLY cheap... . and I've always wanted one. I must say that I'd really like to stay with a Cummins... . but I'm not opposed to a Caterpillar... . Detroits well, the jury is still out.



As far as the transmission, I've never even driven one... . I've been in a few and the drivers don't even use the clutch - and from the little that I know they are non-synchronized trannies and you either need to double-clutch or 'just know' when to shift.



I'm doing my homework now, so that when I'm committed to buy one in the next few years, I'll know what to look for.



I've been reading Bruce's website (Diesel Injection of Pittsburgh) for about 3 years and I don't really want to call and bother him for something like this... . I'll save those calls for when I have the truck and want to start cranking it up.



Matt

 

[JHansen]

Amen on the drive tire wear!

Know a couple guys up here with 600's-1 Cat, 1 Cummins. The Cummins literally chewed the tires off on the dyno at Cummins Alberta (they paid for a replacement set of 8) and the Cat tears off its fair share on the road. Actually the guy running the Cat has 2 550 Cats as well-his last truck is a 475 because of the tire wear issues-putting drivers in a truck with that many ponies is asking for trouble. You gotta be pretty cautious with your right foot or your wallet opens up pretty quickly . I was pretty lucky-in my 6 year driving career in the oilpatch up here I never dropped a driveline or tore up a rearend. Had a 15 speed lunch due to old age (ate up a bushing between the input gear and mainshaft?) ,a pressure plate break a return spring, and a clutch disc shed its lining. Few assorted engine failures related to old age-but nothing operator-induced (at least that's my claim ) . Hell I even managed to get 3+ years out of my truck brakes! No fun to follow me around-but I didn't manufacture a lot of work for the mechanic either.



If I was specing trucks for a fleet I'd order around 410 but for my own use I'm afraid I'd be seduced into the big dog! Bragging rights at the coffeeshop don't you know!



Seems like most of the trucks up here are at least 475 any more-only ones less are fleet trucks or body jobs. I loved the 475 Cat I had-my 425 B-block was strong but the 475 would suck it through the air cleaners and blow it out the stacks... . and get close to 1 mpg better while doing it... . Ain't technology grand? All my boss ever had was Cat power-so that's why I lean that way. I'm sure they all have their strong points and weak points-but if I was writing the cheque she'd be yellow-and-black!



Jason

 

[Jeff H]

They dont produce these anymore. But you can still get a KT 1150. Those run can up around 700 to 900 hp with a few mods. I've seen these big trucks with these engines hook up to the sled at the tractor pulls. Nothing else out there has comes close.

 

[kcjayco]

I don't think it was understood what I meant by reflash. If a password is lost, the computer has to be reprogramed. I don't know any Cummins or Cat dealers that will do it for nothing. Most won't do nuttin for nuttin. Actually there are some transmissions that are rated at 1850 ft lbs. and some that are 2050 and one 18 spd at 2250. Most even owner operators are around 1750-1850. The super ten goes to 1850. But the more torque the heavier the drivetrain becomes and weight is a big factor in trucks. Resale value is a big concern right now, with the used truck market over stocked. 18 spd trans and 500+ HP sell better to owner operators than ten speeds and lower horsepower. The ten speeds and less have longer warranty than 13 and 18 spds have, so it's a better value from that standpoint. Most small trucking firms seem to have settled on 475-550 Hp for now and around the 1750 torque level. Detroit offers are in the 500 HP range. I understand Detroit is comming out with a 16 litre also soon. And it is correct on any drivetrain warranty issue they do want an engine printout. Just some more ramblings.