Engine Break in

[William Fullington]

whats the best way to break in a new 6.5? bill heath said to run it at 1500 rpms for 20 min then drive it easy for a while, no hard accelerating. i've also been told to put it underload immediately, get a trailer on it and go for a drive. i've never broken in an engine before so any advise would be appreciated. i'm kind of looking for a script though (do X for 500 miles and change the oil, do X for 1000 miles and change the oil, etc etc)

thank you.
William Fullington

[More Power]

Drive it easy for about 500 miles, then change the engine oil & filter.

Drive it normally for the next 500 miles, but no towing.

Once it gets 1500 miles on it, consider it broken in. Change the oil again at 1500 miles.

It can take a few thermal cycles for the cold sealant used on the Fel-Pro head gaskets to fully set. Excessive cylinder pressures or high coolant pressures should be avoided till then.

Jim

[NH2112]

I'm of the "work it" mindset. After you get it in, run it for maybe 5-10 minutes and change the oil. Then load it up and do 4-6 full-power uphill runs and take it for a short drive after. (You can do this as many times as you'd like, I don't think you can really "over-break-in" an engine.) The important thing is to avoid running it at a constant speed for any length of time as this will lead to cylinder glazing and the rings not being seated.

[William Fullington]

thanks for the input. does any one happen to know what GM recomends for breakin? ive had someone tell me to let it idle for 90 minutes then take it out and run it with load at no particular speed for too long, saying idle is where the most heat and stress is put on the engine.

im finding there are many schools of thought on breaking in engines. this is the first engine i've broken in and am having trouble deciding which school to follow. this is my daily driver and i dont really have the money to do much if i do it wrong. i love my truck and i want to do this right.

[JohnC]

GM says no towing for 500 miles, but that's mainly to allow the ring and pinion to get friendly before loading them up. The only thing in the engine that really needs to break in are the rings and cylinder walls. Most of the break in occurs in the first hour or so of operation, so my feeling is to let 'er rip right off the bat.

MP's comment about the compounds in the gaskets is interesting, though...

[Hubert]

I've only had one new vehicle to break in and it did say not to set cruise control for first 500 miles to vary speeds and not drive constant at first.

Good point thats the whole vehicle trans axles etc. I don't know what the GM recommendations are for just a new engine.

I like the advice of changing the oil fairly quickly. But I would let it get fully warm/hot for several minutes then change and drain as hot as you can (somewhere between the 5-10 minutes and 500 miles ???). This will flush out any assembly greases or lubes they used and get regular oil in its place. Also gets any metal fines, initial ring/cylinder/deburring, (basic metal to metal contact match up), or assembly grit out as soon as possible.

[grape]

rings get broken in by making cylinder pressure or hp, you can let it idle for a year and a half and the rings would never seat.

[moondoggie]

Good Day!

Interesting topic! I've broken in very few engines - mine have usually been broken in by previous owners. ;) I always followed the school of thought that breaking in easy was best. When I helped a friend on his farm for a few years, however, I read at least one diesel farm tractor operator's manual that made very clear recommendations for use during break-in: 1) NEVER idle any longer than long enough to get the oil circulating & a little heat in the motor, a minute or two at most; 2) NEVER run at less than 80% load during break-in. I can't remember for sure, but I think ring seating was the main issue.

VERY INTERESTING! This is exactly the opposite of what I had lived by, although admittedly the few engine's I've broken in were gassers.

A different story: My brother-in-law rebuilt my 1970 Honda 450 engine after I wore it out. When I got it installed & went for my 1st ride, the electric starter would not crank the engine; yes, the battery was not very old & fully charged. This was not particularly surprising - the starting system on these things was borderline at best. This same situation existed the 1st several rides I took - I had to kick-start it. While I was riding, at ~ 50 miles I think, I felt the engine's vibration characteristics change noticeably. The next time I went for a ride, the electric starter worked fine. I always suspected that I actually felt the rings seat.

Blessings!

[William Fullington]

ok, so here's what im thinking.

i'll idle it for a bit to get the oil warmed up and flowing. then put 500 miles on it, avoiding any single speed for very long, and keeping it in 3rd gear (not over drive). no later than 500 change the oil. get a load on it for the next thousand miles and change the oil again, then resume normal driving and 3000 mile oil change intervals.

change the oil warm? never heard of that before, is it possible you wont get all the oil out so your mixing new clean oil with the used oil thats didnt drain back in to the pan? that should be negligable if im going to change again at 1500 right?

[JohnC]

...While I was riding, at ~ 50 miles I think, I felt the engine's vibration characteristics change noticeably. The next time I went for a ride, the electric starter worked fine. I always suspected that I actually felt the rings seat.

Blessings!

Probably so.

As some of you know, my real expertise is in small air cooled piston engines used in aircraft. Break in of these baests is an art form. do it wrong and you get a glaze of burnt oil on the cylinder walls that will never seat. High engine temps and oil consumption are gguaranteed. The only recourse is to pull the jugs, hone the cylinders, re-ring and try again.

Important steps: first, run it at low power, i.e. fast idle, for about 5 minutes until the really rough edges get knocked off the cylinders. Otherwise, the engine can over heat so badly the cylinders sieze or the rings anneal. Let it cool down, check for leaks, then, while maintaining adequate cooling airflow, run the engine for an hour or so at 80-90% power to seat the rings. When the rings seat, power goes up and temps go down. In an instant. Many who do this by flying the airplane also report a sudden smoothing of the engine. Continue with long high power flights until oil consumption stabilizes, usually 5 to 10 hours, change the oil and you're done.

I used to overhaul Saab turbo engines (and the NA ones too) to put food on the table. The rings came with break-in instructions. "Do 3 full power runs from 20 to 50 mph. No further break-in is necessary."

[Hubert]

If no one minds please explain theories and whats the science behind strategies.

Draining hot keeps the lube suspended in the motor oil. I have always heard drain hot to keep contamination suspended in oil. The oil cooler hold lots of oil that doesn't drain cold or hot. I don't think the upper engine hold that much oil and will drain out better warm/hot. Also a just ran engine will have more residual oil coating on parts for restart and less chance of near dry run until the oil pump pumps up oil pressure.

Never heard the gasket setting thing but makes sense. Just thinking too about the coolant sealing tablets are also working and a few thermal cycles to let them set up as hard as possible would be good too. Same idea makes it sound even better.

Sorry to tangent a bit but a new engine is different than a rebuilt engine. Besides the obvious it has to do with the residual stresses in the block and machining a casting block, head, pistons, and crank. Thermal cylces will let the material relax and it moves a bit. A few thousands at most but on a tight new engine that might mean very close initial clearances at places. Rebuilt the block is "seasoned" so things are slightly different. Some old timers will say better.

I have heard the arguement w/o load rings won't seat a few times. Can someone please explain that. I am just thinking under load the piston top has lots more pressure and will increase blowby this seperates the ring from cylinder wall so how does that help seal it? OR is it that pressure forces the ring to the bottom side of groove in the piston to increase "sticktion" and hold the ring out in contact with cylinder wall with more force than just the rings spring force so they rub harder? Isn't ring seating the rings rubbing off any "point contacts" or mismatch of the diameter differences so they "seat" with run time anyway you want to run it?

Watching a friend years ago crank up a new rebuilt race engine he idled a bit valves loose. Warmed engine adjusted valves then revved engine many times over a 15 minute initial run varing rev points and idle time between revs. I am guessing here .... At higher rpm you get more piston side to side movement to rub cylinder wall and piston skirt. Again guessing its to cycle the initial "rubbing" and allow oil to cool this near metal to metal contact.

Its been years since I was up on this but thought on assembly its common to coat piston down with assembly lube oil. Also to coat cam lobes with assembly lube. 6.5 roller lifter may differ. Assembly lube helps prevent direct metal to metal contact on initial run. Oil prime only can do so much.

I have a few other points but don't want to tangent too much.

[Hubert]

John C.

Thanks for explaining experiences. Here is some related info for you. My company makes fine hole making tools and we make tools for some small engine mfg'ers. Air cooled engines especially have complex wall shapes in section. The cylinder casting and these finned wall sections really move on the first few thermal cycles due to the residual stresses in the casting and depending on how aggressive the machining of the bore material was. Note, I have seen several aluminum holes stress relieve and/or spring back smaller than the reamer used to cut the bore. Heard of many experimental engines running good at first til the engine is warm then piston cylinder gualls and siezes due to this and similar things.

[JohnC]

...I have heard the arguement w/o load rings won't seat a few times. Can someone please explain that...

Piston rings and piston ring grooves are designed such that combustion chamber pressure forces the rings against the cylinder walls. More pressure, more ring pressure against the cylinder walls.

New cylinders are very rough and carry a lot of oil. Without ring pressure, the ring skates on the oil, exposing the oil to the combustion process. The oil glazes and turns into a slick, hard deposit on the cylinder wall. The ring now will never seat.

The trick is to get the ring to seat before the glaze forms. With an air cooled engine this is a fine dance between too much pressure too soon and overheated cylinders, or too little and glazed cylinders. With a water cooled engine the former is not an issue, so the plan is to do it as fast as possible.

[More Power]

I've seen photos of 6.5's that had its cyl heads removed soon after a first run produced a coolant leak. The builder used the correct 6.5 Fel-Pro head gaskets, but the cold-seal sealant hadn't setup yet and there was no residual head gasket material sticking to either the head or block decks when they were separated. The head gaskets simply peeled off leaving nothing behind.

Fel-Pro literature indicates that it takes a few temperature cyles for the cold-seal thermally-activated sealant to activate, and properly bond to the head/block deck surfaces.

For this reason, I would run the engine easy for the first few temperature cycles to give the head gaskets every opportunity to do what they are designed to do.

The Power Project 6.5 engine was run very easy for the first 500 miles - with several temperature cycles during that time (to allow the head gaskets to set). It was run more or less typical of a daily driver from 500-1000 miles, then we tested the power capability of the engine/drivetrain. Full power was not used till 1000 miles.

That engine is still running with more than 200,000 miles. The engine will run 3K miles without needing to add oil, and the oil remains amber up to 2000 miles after service. The heads, manifolds, tin, water pump, and the fuel injection system haven't been off.

Jim

[JohnC]

...That engine is still running with more than 200,000 miles. The engine will run 3K miles without needing to add oil, and the oil remains amber up to 2000 miles after service. ...

Then again, it's hard to argue with success.

Can you elaborate on
The Power Project 6.5 engine was run very easy for the first 500 miles - with several temperature cycles during that time

That sounds to me like 4 trips of 125 miles each. Seems like a couple of trips to the supermarket would do the same thing, a lot faster.

[More Power]

The first few runs were 10-15 miles each. I'd bring the engine up to operating temperature, then park it in the garage to check for anything out of the ordinary (always the pessimist). As the engine/truck proved itself, I began using it to commute - 26 miles each way, with a cool-down in between.

I changed the oil the first time at 200 miles and again at 1000. We used synthetic diesel-rated motor oil from ~5K onward (mostly). Amsoil 15W-40 in the beginning, then Mobil Delvac then Shell Rotella syn.

Synthetic oil plays a big part in lowering oil usage and in controlling soot buildup in the oil. The rings seal much better when running synthetic. :)

Jim

[grape]

we fire up $40K+ engines on the dyno the first time with no water in them to set the sealant on bolts and gaskets, usually no more than a minute does the trick. Then after 20 minutes with water in them, they get abused...........in a big way.

[Hubert]

John how are rings & piston groove designed to increase ring seal with more combustion pressure? All the ones I have seen ( only a few grant you ) the rings were rectangle in section view at least to the eye. The grooves in the piston also appears square or perpendicular to piston skirt wall / cylinder wall. Intuetively to me therefore combustion pressure acting near normal to the face of piston & ring wouldn't add any more sealing force??? I don't know just asking how.

My boss said his son's GM HO crate engine the compression ring had something special about the ring face (mating face to cylinder wall) it had a very slight (<0.001") concave face viewed in section: like this
cylinder bore [ ring ( | cylinder wall. I imagine this wears away really quick and seating the ring face becomes square and parallel to the cylinder wall. Seated rings appear kind of like they are sharp square edged to the cylinder bore iirc.

Grape what is the science to abusing the engine so soon? Cranking up an engine no water I would just think the cylinder wall would get really really hot and there would be a significant temperature gradient in the block according to distance from combustion. "Cast iron" would conduct heat relatively uniformly according to material mass but $40,000 engines I imagine exotic casting materials and geometries make a significant difference to the ole production 6.5 block.

[William Fullington]

wow, lost of good input and advice. very much appreciated. cant argue with experience. can you elaborate on the breakin process for the power project 6.5?

also, the power project mentions the dual thermostat waterpump and fan upgrade. Bill Heath of Heath Diesel mentioned that they were not worth the money. Any one else have experience on it? Is it the stock upgrade from '97 on?I dont plan on towing a 5th wheel or anything that heavy. I just want this engine to last. Is this something i should seriously consider in the future? I am already installing the 21" 9 blade fan and upgraded fan drive.

[JohnC]

John how are rings & piston groove designed to increase ring seal with more combustion pressure? All the ones I have seen ( only a few grant you ) the rings were rectangle in section view at least to the eye. The grooves in the piston also appears square or perpendicular to piston skirt wall / cylinder wall. Intuetively to me therefore combustion pressure acting near normal to the face of piston & ring wouldn't add any more sealing force???

At the very least, the pressure is acting on the top and "back" faces, forcing the ring down and out.

In the aircraft world we have all sorts of exotic shapes like wedges, half wedges, etc...

[ronniejoe]

also, the power project mentions the dual thermostat waterpump and fan upgrade. Bill Heath of Heath Diesel mentioned that they were not worth the money. Any one else have experience on it?

Bill Heath is dead wrong on this one!

My experience, plus that of many other Diesel Page members, says that the cooling upgrades are one of the most important modifications you can make to a pre 97 6.5. For post 97 6.5's, the Kennedy fan clutch is all that is needed.

[Hubert]

At the very least, the pressure is acting on the top and "back" faces, forcing the ring down and out.

I see your point the ring has some inherent spring force out then combustion pressure forces ring down and the gap at top of groove allows pressure to get behind ring - between the piston groove bottom and back side of ring Then combustion pressures wants to blow ring out too.

Hmmm interesting. Still kind of question blowby also forcing ring back into groove too. And still think the normal rubbing will seat the ring regardless and leaning towards the the slow approach is better for a 6.5.

Was there a mis communication on Bill saying HO water pump and dual thermostat not a preferred upgrade. I would think he would advise that and not push the tweaked fan clutch??? Unless it was taken out of context for a particular application.

[More Power]

The 6.2/6.5 and the Duramax (and probably most current diesels) use what is called a Keystone top compression ring in each piston. The ring is tapered - both top and bottom surface (wedge shaped in cross section), with a matching wedge shaped ring groove in the piston (the groove itself is made from iron). The wedge shaped piston ring allows compression pressure to force it against the cyl wall. :)

Jim

[JohnC]

Still kind of question blowby also forcing ring back into groove too.

How? If there is blow-by then the path of least reisitance for the gasses is past the piston into the crankcase, not into the piston ring groove. And you still have the pressure from behind pushing it out.


And still think the normal rubbing will seat the ring regardless

Maybe it would, if there was no combustion to glaze the cylinder walls. Once they get glazed the only way out is to hone the cylinders.


The 6.2/6.5 and the Duramax (and probably most current diesels) use what is called a Keystone top compression ring in each piston.

This way,the downward force from the exhaust gasses is converted into even more outward pressure!

[moondoggie]

Good Day!

"Bill Heath of Heath Diesel mentioned that they (dual 'stats, HO water pump) were not worth the money." Where/when did he say this? Based on what I've read here on the Page, that's a pretty radical assertion that flies in the face of lots of Page member's experience AND common sense.

I would suggest Bill respond to this directly & with great clarity - this is most likely a simple misunderstanding. If Bill reads this, or one of you has regular contact with him, please ask him to clarify this. I've never bought anything from Bill Heath, but he certainly is on my list of respected potential vendors. It would help me keep him on my list if he can clear this up.

Blessings!

(signature in previous post)

[Robyn]

I learned the engine business back in the 60's
I take any new/ rebuilt and warm it up on a fast idle (1500)
Check the oil and water and be sure all is well.
Take the beastie out and drive it in a sane manner for about 25 miles.
recheck the water and the oil. Take the sucker out and do 6-10 full throttle runs from 0-60 and 60-0 and then recheck things. The 60-0 is under full compression in the gears to put a back load on the rings. (helps them seat)
Good to go. Change the oil about 500 miles to dump the pre lube and any crud that washed out.
The sucker is ready to take on the world. The key is if all the clearances are done right all is well and if its loose no biggy. If its a tad tight you can run into trouble. Old timers used to talk about them protracted break ins with all sorts of fooling around, this was due to poor fit of parts and the need to let them wear in. With todays Moly rings and precision bearings this break in game is non sense. Just dont get the thing toasty hot on the back side of 37 miles of 11% hell with your 50 foot super trailer untill its got a couple K on it though.

[Kennedy]

wow, lost of good input and advice. very much appreciated. cant argue with experience. can you elaborate on the breakin process for the power project 6.5?

also, the power project mentions the dual thermostat waterpump and fan upgrade. Bill Heath of Heath Diesel mentioned that they were not worth the money. Any one else have experience on it? Is it the stock upgrade from '97 on?I dont plan on towing a 5th wheel or anything that heavy. I just want this engine to last. Is this something i should seriously consider in the future? I am already installing the 21" 9 blade fan and upgraded fan drive.


The High Capacity water pump kits is one of the first mods I suggest for ANY 6.5 whether it loafs or works. It's good insurance, and a no brainer ESPECIALLY for an older vehicle that may well be approaching water pump failure anyhow. The truck that loafs will not show you the heating issues but they are there. The one tht works (especially if it is truly worked) will show you on the gauge.


The 21" fan is not something that I recommend. It is only MARGINALLY better than the steel blade and that is only when it has good ram air assistance. The Hayden Fan clutch as sold by other vendors is nothing more than an OE Borg Warner clutch built to OE specs and purchased by Hayden. I get a lot more for my clutch, but it is the only clutch available for the 6.5 that is calibrated to engage at a temperature 15 degrees lower than stock. Anyone who claims otherwise is a liar. I don't want to come off as rude here, but I get aggravated having made a significant investment in these clutches only to have false claims made. I have had numerous people try the Hayden then take it off because it is no better than the stock clutch...

[More Power]

JK and I disagree on the recommended fan - but that's OK. I'm a big proponent of the 9-blade 21" composite Duramax fan. We do agree on the other cooling system upgrades. We installed an early prototype 21" 9-blade Duramax fan on the Project 6.5 at the very beginning - and JK's fan-clutch was installed after we discovered the stock unit was inadequate. :)

I've since day-dreamed about the newest Duramax caged fan and fan-shroud arrangement..... ;)

Bill Heath sells a cooling kit that takes coolant out at the back of the cyl heads. This concept has come up here in the BB at least once for each of the past 6 years. I've studied the 6.5 cooling system quite extensively, and can't see how this process would help - in fact I believe quite the opposite. But, I'm open to careful studies that prove the point one way or the other. There's no economic incentive for me to push for anything other than the best cooling/performance solution. I've offered to attend a comprehensive engine test, where the engine is equipped with a variety of temperature sensors, and then compare those readings to the 130-gpm and dual t-stat setup. So far, no takers..... :rolleyes:

Jim

[ronniejoe]

That's because it takes a lot of money to set up a test like that.

The fact of the matter is, the data that Kennedy refers to shows the two fans to be nearly equal. As John said, the 21" Duramax fan is marginally better at speed with ram effect, while the 9 blade, 20" steel fan is marginally better at low speed with no ram effect. Either will work very well. The 20" steel fan requires no shroud modifications and makes the upgrade a little easier. The 21" plastic fan will be somewhat quieter in operation than the steel fan.

One has to carefully evaluate claims and make a wise choice.;)

[More Power]

Ron,
I was told such a test was performed with an instrumented engine. I volunteered to attend at my own expense. No takers..... :rolleyes:

Jim

[ronniejoe]

Hmm...

That's interesting. I, too, have heard of an instrumented test... I'm not convinced it ever happened. The rumored test was by a guy who is very skimpy on supplying data to support any of his claims. That brings me back to my comment about the expense involved in performing such a test.

Maybe someday...

[William Fullington]

thanks for all the input. one last question. any recomendations for oil used during breakin? syntheitc (amsoil or another brand?) partial-synthetic (delo?) standard oil (rotella?) i've heard to use the cheapest oil off-brand oil and im kind of skeptical about that.

[DmaxMaverick]

I don't see anything wrong with using "el cheapo" brand oil for your flushing changes, as long as the oil carries the correct API rating of CH-4 or CI-4. You won't be running it long enough for it to fail, so why spend the big bucks. Dollar for dollar, I rather do many cheap changes, than fewer, costlier changes during break in. I don't think I would go for those "recycled" oils, though.

BTW:
Delo is full mineral oil. Not synthetic or blend.
I'd suggest a true synthetic like Redline, delvac-1, Amsoil, etc. Rotella doesn't fall in that category, regardless what they call it.

[NH2112]

The way I see it, any oil that's CH-4 or CI-4 rated is good enough to go in my engine at any time. Our local parts house sells Amalie oils, and that runs $2.40/quart. The Parts Plus brand is almost a dollar cheaper, and says right on the bottle "made by the Amalie Oil Corp..." so why not use it?

[William Fullington]

Good Day!

"Bill Heath of Heath Diesel mentioned that they (dual 'stats, HO water pump) were not worth the money." Where/when did he say this? Based on what I've read here on the Page, that's a pretty radical assertion that flies in the face of lots of Page member's experience AND common sense.

I would suggest Bill respond to this directly & with great clarity - this is most likely a simple misunderstanding. If Bill reads this, or one of you has regular contact with him, please ask him to clarify this. I've never bought anything from Bill Heath, but he certainly is on my list of respected potential vendors. It would help me keep him on my list if he can clear this up.

Blessings!

(signature in previous post)

i apologize for not replying to this earlier. i fell behind reading my own thread. i called bill directly for a recomendation on cooling upgrades and he said that to me over the phone. i have an email from him as well where he says "We use and recommend the factory single thermostat system---we do not like the dual thermostat setup and 130 gpm pump ---- it is not an effective upgrade"

[moondoggie]

Good Day!

Thanks for the update - info like this helps all of us evaluate our potential vendor(s).

Blessings!

(signature in previous post)