- #Motor big cam 350 cracked
- #Motor big cam 350 full
- #Motor big cam 350 series
- #Motor big cam 350 crack
Most likely this engine has had this repaired before.
#Motor big cam 350 series
This was a fairly common problem with the Big Cam series until they went with the lower press fit liners.
![motor big cam 350 motor big cam 350](https://regicarautopecas.com.br/Uploads/Imagens/37851/37840.jpg)
This can be caused by a bad head gasket and/or worse coolant leaking out of the counterbore area which is a serious repair bill.
#Motor big cam 350 cracked
It seems more like air in the cooling system to me, air compressor? cracked aftercooler? I'm open to suggestions from anyone here, next step is to start tearin it apart otherwise.The biggest thing to look for is coolant stains coming out from in between the cylinder heads. However, I am not convinced that this is what is causing the problem, to me the symtoms don't seem quite right. I've had a couple people (not familiar with the low flow system) suggest a head gasket, or cracked head. I have changed thermostats, removed the water pump and checked it out, (was going to replace it but could not find anything wrong with it) This one seems like it will just stop circulating when placed under load for awhile, which rapidly causes it to overheat, when it decides to circulate again, it cools down rather quickly. I have had the radiator redone, and since tested it to be sure it was done right, and it does indeed seem to be working, seem to be getting nearly 40deg temp drop one side to the other.
![motor big cam 350 motor big cam 350](http://www.diwalcostarica.com/pages/jespinoza/wp-content/uploads/2013/05/CUMMINS-S88.jpg)
It has been causing me problems with overheating for some time now. Did you get it solved? I have an '85 Pete 359 that was also blessed with the low flow cooling system BCIV 400hp. I'm quite curious as to what the problem was with your friends truck framtruck01. It is a good engine, and will last a long time if you keep the cooling system clean and watch the Pyrometer climbing hills.
#Motor big cam 350 crack
I have seen a lot of pistons that the crack was there but had not broken all the way through. Which means it will split there and out goes the rod. you will build massive heat on the piston tops and eventually one or more will start cracking, usually dirctly over and in line with the piston pin. This will not hurt a thing, if you remember that. One other thing, you are running in an over fuel condition at 444 hp. After they went to computer on the N-14 the computer would advance and retard the timing so it was not needed any more. That is why they came up with the MVT system. Most if the Big Cam I II and III 400's smoked a little at idle because the timing was set to keep from melting pistons, but it was too retarded at idle to keep from smoking. whith the MVT this is not a problem, as The MVT advances the timing at idle, and retards it the rest of the time. That is why the timing is set a bit retarded. To eliminate the smoke on these engines after turning them up over 400 hp, the timing has to be advanced at idle, but if it stays advanced under power, the engine life will suffer and could melt a piston. If no MVT then you will have to live with a certain amount of smoke at idle. If it has MVT and it is working right then you should not have a smoke problem. You don't have to back the power down, just be sure the pump is set up right. Check with Pittsburg Injection Service ( ) for info on MVT fixes and general info on Cummins engines The Big Cam IV was not one of Cummins better ideas, but changing the cooling system and working over the MVT system will give you a pretty good engine. If the cooling system is correct then cam timing would be the first place to look for overheat problems under load.
![motor big cam 350 motor big cam 350](https://30e366a0b626f9854855-3c5d91bcd0a2859e322cec743189d74d.ssl.cf1.rackcdn.com/128683716_cummins-big-cam-ntc-250-engine-assembly-ebay.jpg)
Does it have the Mechanical Variable Timing system? If so you may want to check that is working properly and set properly. If it was "rebuilt" into a 444, that is a differant story. You say it is 370 HP "Made" into a 444? If by that you mean the pump was turned up, that will likely cause you problems. If the entire system is in excellant condition, it is usable, but is still problematic.
#Motor big cam 350 full
You can change it to a full flow system like the earlier Big Cams. This system was known for over heating problems, and thermostats did not hold up well.