i'll do this again.. motor question
 

my "new" truck search has started. the new truck will pre 2000 for obvious reasons. i have a cat now and i love it. my dad has a 3046E its amazing (after 9 months of a botched overhaul.. thanks Pocano pete....).

the truck will be held on to for as long as i can. my truck will be put out to a driver in april/may. so i'm looking at petes and KW's. 379 petes, KW W900, T600, T800 (if i could find one). while i'm very happy with cat and it is my first preference how are the N14's? fuel milage? reliable? how do they pull? my dad has a ISX and while i know its rare for the years i'm looking at (i found a signature 600) i would really like to stay away from them. NO ONE will work on them here.

lastly the detroit.. i know they're excellent motors and i do know geared right they can pull ok. as of late i'm talking to some people that are getting horrible fuel milage.

for right now i run out 7800-80000 on the nose across PA into ohio 2 times a week, normally come back light (10000-15000).

i think ideal for me with a cat would be 550hp, 13 speed low pro 24.5's and 3.55's. i normally run 70mph all the way (well try with my current truck).

well... what do you guys think? opinions?

I'm not selling, not yet anyway...))
The CAT you are looking for (pre2000), will have a sweet spot at around 1400 RPM, at 70mph and all of the above, it will run around 1500. Also, i'd more concern about torque, than power. Never had N14, but from what i've heard, it's a good reliable motor, with the excellent pull (525). It's also cheaper in parts, and maintenance, average fuel economy... Even being a die hard CAT fan, it's a very good choice IMHO.

thats what i'm hearing. they just don't sound right lol. i just don't know anyone that has a n14.

some say that when a detroit is setup right they pull like bulls. personally.. i've never seen it.

I Can say I love my N14 Red Top. Plenty of power and torque, but I love the reliability the most. Did an in frame ourself for around $7000.00. The only reason it needed it was I blew a head gasket, and well while you there why not. It had 843,000 on it. 1.2 million now and no troubles

what kind of truck and what kind of milage are you getting?

1999 Peterbilt 379 EXHD. 13 speed 3.70 rears. Pulling a reefer or box I can get 6.5 mpg if I stay around 62 mph. But I run 70 mph and idle when I sleep. Most weeks truck doesn't shut off after I leave the house till I get home and I average 5-5.3 for the week including all idle time. I like to be comfortable when I sleep. And yes it's my fuel, my money. Not company truck.

pulling hills at 80k no idling you'd say 5.5 then?

I would say that would be a good average, but I think if driven in the hills with peddle instead of cruise, you could do better. I have found that my truck pulls better at 80k than 70k. Its weird I know, but it just feels like it works better fully loaded. Also most N14's run better pulling hills if you don't have your foot slammed to the floor, but instead about 75-80% throttle. I can't explain it, just feels that way. Let me say this, I would buy more N14's without hesitation. Yes Ive driven cats, just personally not a huge fan. I would buy a detroit 12.7, but have it tuned, then they will run. Also N14 is pretty much same block as the old 855 cummins, again great engine. N14 Block been around for better than 30 years. My advice is to find the right truck for the right price, everything else is just LUCK. Hope Ive helped. Anything else I can answer for you, I will try.

you have helped. i know no one that runs n14's. i run a cat now and i love it. my cat is the same way with running hills 75-80%. i think it'll be the right truck at the right price when i see it.

Firebird a Detroit Diesel if you can find one for sale as the drivers have one will not be willing to let them go. A pre 2000 Detroit 500 hp setup with a 13 speed and 3.55 gears will get you between 8 MPG cruising down the highway at 70 MPH how do I know this I was a test truck driver at my last fleet testing the 14 Liter Detroit that was setup for 665 HP 2250 Ft Lbs of torque and and I was getting 7 MPG out west running 75 across I-80 for days at a time. MY idle time was high at about 40% as if I was not moving I was running the truck also due to I had a Beagle with me and I was not going to let her be in a hot truck at anytime if I was taking a shower or eating. Yet I was still getting 7 MPG pump to Pump on the Mileage run not the ECM of the truck it was showing 7.6

The one weakness of the Detroit is that bull gear setup however by now anyone that has one more than likely has upgraded the gear.