Cummins NTC 350 Help

From small cam to big cam is the overhead adjusted differently?

As far as clearances go

injector settings are 60 in lbs on that eng.

Ohh alright then.

I'll get a picture tomorrow morning.

The one in your photo above is a big cam, I'm just making sure you didn't set the overheads on a small cam if that could be what you have-to big cam settings. Big Cam CPL's start
with the Big Cam I and the first CPL # starts at 205

Actually its even easier than that, look on that engine tag again and see what the timing code is-if it says something around 36 timing code it's a small cam. If the timing code runs from
66 to 70 it's a Big Cam. The photo you posted didn't show the whole tag which should also show the timing code if still readable or Cummins even stamped the code on the tag, sometimes they
didn't back then.

So I ran to the shop to check the tag. Apparently some of it's missing. I couldn't find the timing. But I took a couple pics of the followers.

Just as I thought you have a Small Cam not a Big Cam. So pull the rocker covers and jakes if it has them. firing order is 153624-bar the engine over til it comes at A with 1 valves closed,
set the injector at 68 inch lbs intakes at .014 and exhaust at .027. Set injector first then set valves. Set valves and injector and valves all on the same cylinder each time. But you might
have some injector issues with the fact you set them to big cam specs. So first I would I remove the injectors and replace with rebuilt ones at about $45 bucks each . Plus check the
injector push tubes that those are not bent and full of oil by tapping the end straight down on a concrete surface-should sound hollow not a thud. Plus check the valve push tubes to
make sure those are not bent also. Torque the rocker boxes to 70 ft lbs and jakes to 65 ftlbs if it has them. Set jakes at .018 lash

Ok, can do. I'll let you know what I find. Thank you.

I was always told with top stop injectors to use the inner base circle method. And what your telling me is to adjust valve and injector on the same cylinder correct?

Below are two photos of the 855 injectors, The one with the exposed actuator/plunger spring is a small cam injector. The other unitized model with no plunger spring showing is a
Big Cam Top Stop Injector. Yes on small cam engines like 220, 335 and 350's you set both the valves and injector on each cylinder at the same time. Just run through the firing
order stamped on the after cooler, the 153624 firing order will correspond with the A,B,C marks on the accessory drive pulley-plus it will be stamped 1-6 next to the A mark and so on for each
letter stamped it will show that cylinder also . You might have to use some sand paper to find those marks on the pulley.

Don't feel like the lone ranger for setting the overheads wrong, I guarantee you it's happened thousands of times. Just figure it as a learning experience, we all make mistakes.
Plus I'm not the only one on here that knows these old critter Cummins engines guys like RZucker, DMiller, Petepilot, kshansen, Junkyard and funwithfuel just to name a few that can help
you. This forum is full of sharp mechanics with a scope of ability from A to Z. It's all free help, and no one on here would ever purposely steer someone wrong.

Truck Shop

My injectors are the first image shown. On monday I'll pull it apart, check the Injector push tubes as well as the valve push rods for bends. Replace accordingly and start back with the over head. Back to my previous post with the wet cylinder. Do you think that is from having the Injector set incorrectly or possibly a ring issue or seal failure like you had stated before? I've got plenty of down time on the farm right now to tear it all down and rebuild.. I appreciate all the help. You've given me more helpful knowledge than anything I can find on the internet and trying to find an old cummins manual has been a pain as well. Thanks again.

Well it is a old engine with probably hours and miles on it, but the fact there is a issue with the overhead adjustment that was done and that can screw with the injector plungers and cups.
I think at this point it would be worth the gamble to install a set of rebuilt injectors, adjust and retorque the upper end and see how it runs before jumping into major repairs.
You don't necessarily have to remove the rocker boxes to remove an injector but it would be wise to blow the dirt off everything all the way down between the heads before you remove
rocker boxes. And by a set of rocker box gaskets and a bag of 12 fuel cross over 0-rings and reseal those areas along with the rest of the job. You can also adjust the valve bridges while
you have everything off/there also know as crossheads, those set on top of the valve stems. To adjust those loosen the jam nuts and back the lash screws off-using your thumb to push down
in the middle of crosshead {with some force} turn the lash screw til it stops. Then turn it 1/8 turn-you will feel it rise upward as you push down-tighten lash screw lock nut. Set all the same.
When assembling put a small amount of oil on all threads before torquing, things just go better that way. There are a few tools that will make the job easier and necessary if you have jakes.
I will post a photo of what is needed.

Awesome thank you. I'll get er taken apart Monday and see what I find.

Some tools that make the job easy, Dial type inch lb torque meter, extra long 5/8 jake socket if you have jakes and a 3/4 overhead wrench for braking jam nuts loose but not necessary.
The step washers on the rocker box studs are getting hard to find so don't lose them, and those are a must between the nut and rocker box and only those.
One other thing when installing the 1/2" nuts on the rocker studs that hold the rocker boxes down---do not get a case of butter fingers and drop one down through the push tube cavity.
If you do-you will have to remove the oil pan and find it. If a nut falls and nests it's self in the cam followers it can on start up wedge and break the the cam follower or the block.
The engine might bar over with the nut in the cam follower but it will get pitched on start up.

Thank you, I do have the 3/4 and the extra deep 5/8 socket. And I'll definitely take my time with the step washers.

I once lost one of the washers down the inside but got lucky. I heard it go all the way down into the pan. after draining the oil, I got it with a flexible magnet. sometimes I get lucky- it helps to make up for the times that luck is against me.

There are definitely those times were you get lucky like that. Usually if it starts out bad for me, it goes south from there

The real trouble maker is the two 1/2 nuts in the center, gravity really comes into play with those two.