400 big cam advice.

Diesel Controls Inc out of Massillon Oh, one of the best places I have dealt with for injectors, they build pumps too. More knowledgable and polite than Pittsburgh would ever think of being.

Head bolts only need replaced if the bolt is pitted or corroding, they are not torque to yield bolts that you throw away after one torque.

High flow cooling requires essentially the whole cooling system be replaced, they run warm as that is how they were designed compared with earlier 855s.

 

We had one for a little while that ran well, but I can't say for sure that it would not have ran the same with the air to water.

 

What is weeping from the head gaskets and is it one, two, or all the heads? The ones I remember ran 210F in a pull when they we new.

 

It is a 531cpl 400BC3, and yes intake manifold is off of a N14, those are the only series to use air to air so that is where the parts come from.

 

Yes you can install air to air from a N14. You will need all of the parts though. Intake manifold, tubing and front cooler. Try a local Truck Wrecking yard for the kit. The best thing you can do in my opinion is convert it to a high flow cooling system. I ran a Big Cams for years, one of the most dependable motors Cummins ever made, and you could turn some serious power out of them. The BC4 they went to low flow, and it can give you fits. There is a filter ( screen ) in the cooling lines at the front of the engine. If it plugs you will overheat. Also they have dual thermostats. Overall just a poorly designed cooling system.

I run all N-14's now, and will stay that way. They are around 2002 year trucks. These are very nice engines for flatbed and heavy haul. My stock 525 will pull with the kitty's all day long. My 460 regularly pulls 115k for lowboy use. Not the first to the top of the hill, but very dependable. The truck in my avatar has the 460. These motors are very simple to work on also, including the computer systems.

As far as turning the motor up on a 400, be careful . If you are careful it will last you a long time. Been so long since I turned one up, but the pump will most likely get a new button, spring and have to be shimmed differently.
The injectors will help keep it cool, but on a long pull they will get hot. You need to live by your pyro when pulling long grades like we have here out west. You also need to keep it 1800 to 2100 when pulling long grades.

As for the heads weeping. Been an issue with 400 Big Cams for years. The heads move around on the blocks. Same for the N14's. The more the power the more likely they will move a little. I never bothered changing head gaskets that were weeping unless they were really bad. Reason the old timers were telling you to use new head bolts is that they are known to stretch. I always reused mine with no problem. If you do change head gaskets, make sure to check your liner heights. Cummins were known for dropping a liner at times. Highly doubt that is the case for you as you have no water in your oil, plus by the time they came out with the Big Cam 2's they had most of the issues worked out. Last thing to tell you is if you work on this motor, do NOT take the cam side covers off without knowing what you are doing. This is how they time the engine, and the gaskets are shims. If you change the shims without knowing what ones to put back in, you will not be a happy camper.

Have fun, this is a great engine to start trucking with as you can do most of the work yourself, and the manuals from cummins for these engines is very easy to read. I am sure someone on line has a PDF for one.