Breaking Cummins In
 

Its almost time to fire this build up and I am looking for engine break in procedures.

I was searching and found this thread Engine break in? - Competition Diesel.Com - Bringing The BEST Together
which talks about breaking the engine in for a few minutes with no coolant at 1800-2000 rpm.

I am just curious your experience with this?

If you have a new cam, keeping the rpms up is the most important, don't let it sit there and idle until an hour or more of run time. Zinc additive is also important, I would fill the coolant up and just worry about the cam most.

Put coolant in, run it, check for leaks, get the rpms up and break the cam in, check for leaks again, go beat on it and seat those rings.

Vary the RPM's and don't let it idle for more than a minute or so. Load the engine some but don't build high boost. Seems to have worked for me so far.

Breaking Cummins In
 

Is there a NEW cam in? Not new to you, I mean like it's never been in a truck before. If so, then refer to the manufacturer for break in procedures.

Aside from that, I would use some sort of ZDDP additive in the oil to minimize wear of metal to metal components (pretty much everything). You can hook up a trailer to it. That is the best method. Tow something around for about the first 500mi. or you can beat on it. I did the later. My truck seems to run fine 10k later. Bottom line, you want to put it under load to seat the rings ASAP. Or, it'll just take longer lol.

Lastly, run a cheap oil and filter for that first 500mi. then switch to the oil you plan to regularly run. Any crap still in the block or the head from the machine shop should be mostly cleaned out in that first 500


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You risk everything running with no coolant, and nothing will break in after a 5min run anyway.

thanks. it has a new everything in it. The machine shop decked the head and the block. It has carillio rods, 12mm gorilla girdle, new coated qsb pistons, mls gasket, new injectors, new oil pump, new oil cooler, almost new firepunk compounds, new exeedy 350% injectors, new ats dual fuelers, new hamilton 182/214 108 cam, springs, push rods, new lift pump on a stock 68rfe so I dont know how much beating i can really do on it until I can put a built 47re in it.

Do you have a set of stock injectors to run during break in?

nope, i sent the stockers in for cores.
i also have new tappets and probably many other things i forgot on that list.

I agree with what everyone says, except running cheap oil and a filter. Buy a good filter, and good high zinc oil like Brad Penn, along with an additive like others have mentioned. Just don't run a full synthetic oil for a while. It's always a good idea to start it up with a couple sober friends to help check for leaks and stuff. It's not a complicated process, but you can screw it up easily.

Fill with coolant, run at 2000 rpm for 10-15 minutes. Mainly to break in the cam. Run the engine like you intend to use it mostly to break in the rings. I always use zinc additive for the fist oil fill on a new engine.

I'm about to start my new eng also, from what I've gathered is the same as everyone above, said, a couple things I plan on doing is making a pre oiler to ,well ,pre oil everything going through the oil galley from one of the holes like where the oil press sender goes , that way you know oil made it up top. Plus it'll save the starter. from what we've done in the past with gassers was use break in oil, it doesn't have all the additives that'll slow the rings form seating and it's hi in zddp, we always added a bottle of it also. my plan is to do the cam break in like Zach said , change out filters ( use good ones from the start ).Drive around going through the gears, esp doing some down shifting, putting some back pressure will help the rings seat and wear in both directions, like the first 25 or so miles, then hook up and drag a trailer, I believe going up and down hills and down shifting for some back press, leave the break-in oil for a couple hundred then change it all out . I'm running power driven's oil as it seems to have the most zddp ,which our flat tappets and cam need..Just my .02 this is for street.. drag only motors are a diff story,lol, but like everyone said don't let it idle or baby it, it'll take forever to seat the rings and if you glaze the cylinder's well it prob wont ever seat and it'll have tons of blow by. ... Like I said just my opinion . Oh and maybe check head tq. after the cam break in, I figure I'll at least check a couple and see, if it's good I'll do one hot after a couple miles or so. Any input on that one would be appreciated..

My theory is break it in like the factory would, and though it's probably something that's kept under wraps, one could speculate that even the testing in the facility is brief and more for just confirming that the engine turns over and maybe runs within a few specs. Hence why the manual has a "break-in recommendation" section. If they took forever testing and breaking in every single engine I couldn't see them being able to crank them out so quickly.

I think it boils down to assembly lube and a good prime prior to starting the engine up The break in will naturally occur through driving and heat cycling. As long as everything is assembled properly, everything should be fine on the first start up and no excessive wear should occur.

The length of time it takes is essentially what you're playing with in regards to coolant or no coolant. Heat can help seat rings, but obviously there will be a point of diminishing returns. The risk is not worth it and at the end of the day you're not going to see a difference one way or another (provided you do either correctly). Run it with coolant and put a load on the truck. Everything should seat quicker that way.

I agree with your last sentiment. I was told long ago that CMEP (I think I watched a video) weighs and X-rays the engines to check for oil and other defects, and then couples it to a drive assembly that 'runs' the engine to check compression, and then out the door. It never fires fuel.

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