Breaking in a rebuilt engine.

[Brad S.]

Many of the senior OB members have said its good to work a rebuilt engine to get the rings seated.
Instead of hooking up a trailer how many pounds of extra weight, in the box, would be good enough????
(Not including driver weight...)

 

[icanfixall]

A ton is my best guess. Make sure you do lots of engine revs up and then allow them to drop down. Kind of like driving in first gear to about 3000 rpm. Then let off and allow the back side of the rings to work on the cylinders. When your under power you wear the rings differently than when your our of the throttle allowing the engine to run on back compression. Its not a good idea to run at a constant speed like on the freeway. Its also not a good idea to drive round town lazily either. Working the engine keeps the oil burned off the cylinders and the rings.

 

[franklin2]

Sounds like the same break-in procedure that is used for the gas engines. Running the engine hard for short burst increases cylinder pressure which presses the rings out against the bore and helps them seat. But running the engine hard for long periods can cause it to heat up and form a glaze on the cylinders that makes it difficult for the rings to seat. That's where the up and down thing is coming from.

 

[Greg5OH]

what do you mean form a glaze from heating up? that is nonsense. the only time your cylinders will have a glaze-and its not a glaze but simply a well polished wall, is when they are worn and tired with no cross hatching left. icanfixalls procedure is perfect.

 

[icanfixall]

The cylinder and ring glave is actually a varnish that is not burned off the rings or cylinder. It will cause the breaking to last for nearly 50,000 miles in worst cases. This is why you put the engine under a slight strain. Run it up in the rpm then back off and allow the back compression drag the pm down. Do this in a huge parking lot till your going crazy. Or load up the rig and haul with it. In a very worst case you have to machine off this barrier on the cylinders if you can't make it breakin.

 

[Greg5OH]

what is a glave?

 

[icanfixall]

I'm not a very good proof reader. Sorry for that too. I meant to say glaze.. Not glave.. I'm old and not too good with my fingers.

 

[Greg5OH]

Oh glaze! Wow how did i not decipher that.
Where is this varnish coming from?

 

[idiabuse]

Certain engine oils cause the condition known as "GLAZING" this happens a lot on marine engines with wishy washy boat owners who hate pushing two Detroit Diesels, they end up buying extra oil extra labor and end up getting a for no reason engine overhaul because Top Grade oil is just way too expensive initially !
I used breakin oil for 1000 miles on my engine.

 

[chris142]

imo it needs to work some. idling at red lights wont seat the rings.

 

[franklin2]

There are many variables that affect break-in and the time it takes. The material the rings are made of, the roughness/pattern of how the cylinders were honed, etc. The main thing is as soon as the truck is driveable and you can get out on the road, you find a road with not much traffic, slow down as much as you dare, and then floor it till you get to the speed limit. Do this 10-20 times initially, and that will give the rings a good head start on getting cozy with the cylinder walls.

 

[icanfixall]

If you really want to hurt your new engine just drive around town to break it in. Going to the market or church will not break it in. These engines were designed to work for their fuel. Watch the temps and work the engine.

 

[riotwarrior]

Many of the senior OB members have said its good to work a rebuilt engine to get the rings seated.
Instead of hooking up a trailer how many pounds of extra weight, in the box, would be good enough????
(Not including driver weight...)

What are we talking in regards to rebuilt?

Just new rings, bearings, and gaskets with no machining other than honing a bore and re-using old pistons?

Or are we speaking about ALL new pistons and over bored and valves ground and all new bearings etc, essentially a remanufactured engine vs overhauled.

To me they are different beasts and usually I do things a bit different. Answer those two questions I'd offer my thoughts too but otherwise nope!

 

[Brad S.]

Here are the details on rebuild.
Bored out .030, new pistons, new rings, new bearings,(rod, main, cam), and line bored & rotating assembly was/is balanced.
Heads have already been rebuilt, new valves, guides, seats, milled, new valve seals.

Another couple questions along the "break-in" thought.

Machine shop guys said do this for about 100-150 miles???? Thoughts on that..???

I have to replace 2 of the wrist pin bushings, had a spot on both that was broken or "notched" out.(post pics later)
I'm in a spot where I could pull the 6 piston/rods out and replace them all...????
Outside of using a "mic" on em any way of knowing if they are bad..???

 

[towcat]

fire it up and let it idle long enough to verify no fluid leaks and no strange noises. after that, find the heaviest trailer you can hook onto, then drive it like you just stole it. it's that simple.