Proper way to seat rings?

[WarWagon]

Curious if there is a proper way to seat new rings on a 6.5?

The rings I have from the rebuilt engine did not seat properly as only the bottom half of the 2nd ring have the break in coating worn off. This is after 30,000 hard towing miles and unknown use before I got it.

 

[JiFaire]

The old-timers (jeez... listen to me!) always talked about pouring a little Bon-Ami in there to help them seat. Matter of fact, GM issued a TSB to that effect way back when... gave instructions on how much to use, etc.

Dad taught me that adding Bon-Ami is like putting a year's wear on your engine; said that if you hone the cylinders properly, you never needed to do anything else.

Now, I'm not really sure if Bon-Ami is a good idea, because I listened to Dad and always made sure I did a super good job of honing the cylinders.

In every rebuild I've done, the rings seated without Bon-ami. Maybe I'm just lucky. Or maybe he was right. Again.

 

[Chief915]

I haven't used any "additive" type stuff for breaking in rings, not saying that it's wrong, just a different way to skin the cat.

I think a good cross-hatch in the cylinder to start off with and then putting a good load on the engine (even just some spirited driving without towing) would be all you would need to seat/break in the rings. Idling for too long after a fresh rebuild or even cruising around at slow speeds/light engine loads could cause the rings and cylinders to glaze over in my opinion. Start it up the first time, check oil pressure, check for leaks, set the timing, then take it out and romp on it a little.

Again, there are other methods, this is just what has worked for me.

 

[NVW]

x2 on the loading, I remember some mechanics going for some 0-30 runs. Back in college we rebuild a JD 4020, after it was warmed up on the dyno our instrector would load it up for a couple seconds, then repeat a couple more times. It wasn't full load, just make it snort a bit.

 

[Crankme69]

On my Harley builds I do a few short like 1 min heat cycles 1st allowing the motor to cool completely between them not at idle but blip the throttle between 1200~1500 rpms. After another cool down I then take the bike out & load the motor in 3rd gear hard up to 3K & then allow the motor to bring the rpms back down to 2K about 10 times & it's done ready for an oil change & normal riding.

I know the 6.5 is not an air cooled V twin but the heat cycles & allowing the motor to do some breaking while slowing might apply.

 

[GM Guy]

my boss' theory, at least on farm equipment, is to load the piss out of it (not overload, but take it to 90 percent load or so) right now his buddy overhauled a 8300 mfd deere (motor got dusted by PO) and they have it hooked to a set of 6-5 flex kings (whenever 6-5 flex kings are mentioned, guess what I think of! ) these are alfalfa crowners, sweep plows, sweeps, etc. basically 6 five foot v-blades that skinm under the surface and they cut off weeds, pull harder the first time around in the spring, so the tractor is getting broke in nicely.

 

[bison]

It depends if one uses a used block or a new or bored out block.
The cyl bores in a used block won't be 100% true and have wear as in "out of round and in taper top to bottom". Just honing to get the glaze off and get a fresh crosshatch in it wont do anything to get the bores back to true.
As a result new rings have to wear to the shape of the bore and it can take a long time for them to seat even when break in is done properly.
On my 98 it took over 20 k before the oil burning stopped(used block with very little ridge in the bores(just honed),used pistons,new rings)

 

[Franko914]

I helped break in my brother-in-law's 86 sub when he drove it out of the showroom. Drove the first 1,000 miles below 50 mph, never going over 2,100-2,200 rpm, kid gloves acceleration/deceleration, neither heavy loads nor towing. Then, brisk acceleration up to 65 mph (not WOT though), slowed down to 35-40 mph, then repeat acceleration up to 65 mph... about 12-15 times. That truck never needed any addition of oil between oil changes and ran as smooth as when it was driven out of the showroom.

 

[robzombie4551]

Yeah , what franko said.

The key is constant rpm change, not a steady diet of the same rpm.

you should keep a Light to medium load, no heavy towing for atleast a thousand miles, and no prolonged idle, or steady highway speed at the same rpm or load.

After that have at it, and the motor will only keep running better as it loosens up.

You are looking to get as much variation as possible when breaking the rings in, compression versus decompression.

 

[Edzzed]

I remember my first engine break in when I was 17. It was a Kawasaki KZ750 twin. They never told me about how to break in a rebuilt engine so drove from Vancouver BC to Seattle and back in a day. When I got home one pipe was blowing blue. oh no. Needed a new cylinder put on at their cost. Key is to vary the engine load and speed without going over 50% of the redline for the first 1000 miles then a wee bit more of a load without going over 75% of redline for the next 500 miles, after that Bob's your uncle. Doing a constant 70 mph don't work.

 

[racer55]

Yeah , what franko said.

The key is constant rpm change, not a steady diet of the same rpm.

you should keep a Light to medium load, no heavy towing for atleast a thousand miles, and no prolonged idle, or steady highway speed at the same rpm or load.

After that have at it, and the motor will only keep running better as it loosens up.

You are looking to get as much variation as possible when breaking the rings in, compression versus decompression.

*2
That's how I was taught and it's the same procedure we use on the dyno with racing engines.

 

[3500GMC]

Loading and heat cycles are both a good thing.

As stated, out of round bores with just a hone job and new rings will take a while.

As for the build procedure, use a conventional diesel oil for the break-in AND for the cylinder/piston/ring install. Avoid synthetics, greases and other junk for the cylinder walls.

 

[great white]

.... always talked about pouring a little Bon-Ami in there to help them seat...

 

[ak diesel driver]

Loading and heat cycles are both a good thing.

As stated, out of round bores with just a hone job and new rings will take a while.

As for the build procedure, use a conventional diesel oil for the break-in AND for the cylinder/piston/ring install. Avoid synthetics, greases and other junk for the cylinder walls.

Try to find some of the old oil that has the good stuff in it for break in.