A friend ask me to replace two injectors and run the overhead on his N14. It has Jake Brakes. Any thing I should know about it? I have did a CAT before but not one of these.
Truck Shop knows the most about these engines. If he does not see your post you could try PM him as he has helped out a lot of people. Might want to have the CPL# for him as he may have some better idea of all you need to look out for. Simon C
I just return after a 12.5 hour day on the road, I will come back and cover it tomorrow morning.
Firing order--1,5,3,6,2,4. All injector and valve adjustments made on same cylinder A-1 B-5 C-C A-6 B-2 C-4 Intakes .014 Exhaust .027. Injector unlock adjuster nut a few turns, run the adjuster screw down till it just bottoms. Back it off and repeat running it down again two more times to remove oil. Run it down till it just stops/bottoms, back off two flats of hex head or 120 degrees, tighten lock nut to 50 ft lbs roughly. Set injector first then valves on each cylinder. Info is for Celect, Plus. C-Brake lash should be on housing, but .023 IIRC.
Thank You Truck Shop! I think I understand most of that. I am a little unsure on setting the injectors. Do I run the adjuster screw done until it just touches the injector plunger or do I run the plunger down some to? I was reading part of a service manual, and it talks about step timing control (STC) injectors and how you use the outer base circle method to set them. I'm alittle confused by that. Maybe those are not on this engine.
Is yours a STC N14 Mechanical or a Celect Electronic N14? What year is it? N14 Mechanical STC engines stopped production early 1993, Celect & Celect Plus are late 93 up to 2001. STC uses a different injector setting and that depends on CPL number. Need that number too.
The truck is not at the shop right now so I can not look at it. He wants to work on it this weekend so I'm just trying to prepare. I know it has electronic injectors so does that make it a Celect? Where the STC N14's only mechanical engines? What is the difference between the Celect and the Celect Plus?
STC ran from 1986 to 1993 in Big Cam IV's, 444, Mechanical N14's. Mechanical N14 only had a 3 year term. Celect/Celect Plus are all electronic tier 1. Celect was a lower rated hp engine group with a narrow field of options, Celect Plus or commonly known as Red Tops because of red valve covers had a wide range of parameters. * The injector setting is simple just like I explained. The adjusting screw at injector rocker lever is loosened, lock nut backed off a few turns, then turn the hex head screw down easily till it stops-bottoming injector plunger. Back it off a full turn then bottom again three times to squish oil from injector, run it back a fourth time till it stops/bottomed {don't over tighten just bottom it each time}. Then back screw off two of the hex head flats {120*} holding that screw with wrench tighten lock nut. Mark the screw once bottomed to see you've backed it off exactly {120* or two flats on hex head} The screw head will be 7/8" All injector/valve settings are set on same cylinder using firing order and A-B-C marks on Accessory drive pulley. Just like I posted above. * If it has Jakes/engine brakes, those will have to be removed to adjust valves. Jake housings have bolt torque value of 75 ft lbs.
I ran the overhead on this today. It was real easy once we got the timing figured out. The accessory drive must have been put together wrong. C was number 1 and so on. Truck Shop can you tell us more of the history of the 855? I have heard that some are big cam and others are not. What is the difference and how can you tell? What is the 444, I've never heard of it.
That might be a lot more than Truck Shop or anybody wants to type out. There were many versions of 855's and other Cummins engines.
Pass.
Back in the day, here anyway in the cummins cat saga. You wanted a 4 and a quarter cat or a cummins per 444 mance. Isn't that when cummins went from beige to black?
The first 15% of 444's were beige, then black. 444 was just a slightly fueled up NT88/BCIV with same STC injection and low flow cooling. Kind of a dud like the rest of the fours.
I was wondering if anyone has tried different settings on the injectors? I have heard of people backing them off more, like three flats (180 degrees ). What would that do? Some people say it will help the fuel economy. The owner says that he is not getting as good of fuel economy as others that are running the some setup.
Never heard of that, the setting is for injector preload. First off everyone gets better mileage, don't believe just ask them. If he's getting 4.8 to 5.2 fully loaded that's about all a N14 will muster.