Author Topic: Breaking in a new engine  (Read 17244 times)

Rtqii

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Breaking in a new engine
« on: August 15, 2006, 12:37:39 AM »
I want to give some un-solicited advice to new engine owners on what to do, and what not to do, during break in.  I am going to pre-face this by saying I have not received delivery of my engine yet and I have not broken one in.... However I have blueprinted and run-in high performance engines before, and I think I have a pretty good understanding of the Listeroid quirks. My advice comes as a result of some hard won experience.

To the rest of the group here, please feel free to chime in with advice, corrections, or to point out any omissions or add opinions. I am happy to discuss my reasoning here  ;)

To start with we are going to assume that your engine has been inspected, and is in fact clean and ready to run.

1) Do not use synthetic lubricants during break-in. Synthetics are great to run in a working engine that has settled in, but you will cause yourself unending headaches if you start out with a synthetic oil.

2) Do not use a high detergent oil during break-in.

3) Do not use multi-viscosity oil during break-in. My personal recommendation for breaking in a Listeroid would be to use straight non-detergent 30W or 40W and I would lean to the 40W during my own break-in.

4) It helps if the oil is pre-warmed for the initial startup (a small immersion heater in the crankcase could be used), and do not start up a dry engine... You should pre-lube everything. Get a pump oiler, put it in a crockpot with a couple inches of water; once hot shoot a squirt of hot oil into the tops of the cylinders, cam bearings, crank bearings, etc. while slowly turning over the flywheel. Be sure to manually prime the oil pump if so equipped, and shoot some oil on all external moving parts. Make sure the fuel rack is clean of paint or gum and put a drop of hot oil on all the linkage points.

5) It does not hurt to put an ounce or two of oil in the fuel tank.

6) It does not hurt to put a couple of strong magnets in the crankcase to collect metal filings.

7) Do not start an engine without water in the engine cooling jacket. People think that they can fire up a dry engine and run it for 2-3 minutes without overheating... This is a mistake. Most of these engines have "wet" cylinders, and hot spots can form nearly instantly... 2-3 minutes can result in damage without coolant. If you wanted to be really gentle on an engine, you would pre-heat the water as well as the oil.

8) Do not run a new engine, even for a short time, without a load. Diesel engines, especially new diesel engines, have to have a load on them in order to keep the rings from chattering. The pressure created when a load is applied and the rack is open is essential for seating the rings and ensuring that they stay seated and don't scuff and vibrate in the bore. This is especially important during break-in.

9) Don't grab the rack and race the engine up or otherwise permit it to overspeed... Instead, pile a load on it and gradually work the rack open to develop power... These are not racehorses.

10) After a few hours cumulative running with varying loads applied, drop the oil while the engine is hot, open the access panel and mop out the sump, clean the magnets. You can fine filter (2-5 micron) and burn your used engine oil so don't feel bad about making frequent oil changes during break-in... These engines have virtually no filtration system and unless you have modified things with the addition of a bypass filter system for the crankcase sump you will want to remove metal, water emulsion, and any sand frequently. Let used oil settle before filtering and mixing with fuel, and toss the bottom sludge.

11) I would consider the break-in period pretty much over after 100 hours under a load, but some of these pointers can be applied every time you start your engine.

Good Luck!!!



TPXX

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Re: Breaking in a new engine
« Reply #1 on: August 15, 2006, 01:29:19 AM »
Sounds reasonable. Do you have an engine coming?

Rtqii

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Re: Breaking in a new engine
« Reply #2 on: August 15, 2006, 01:54:27 AM »
Sounds reasonable. Do you have an engine coming?

Yes, I am also buying land, and building an engine house to run it in... I am moving off-grid finally.

mobile_bob

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Re: Breaking in a new engine
« Reply #3 on: August 15, 2006, 02:02:07 AM »
i would go a step further

that is i would have two things in place

1. a variable load,,, that i can adjust easily, such as the gen head and a load bank.

2. i would remove the crankcase reed valve so i could monitor the crankcase pressure in inch of water on a manometer, and adjust the load from 25% to full load over the length of time it took to maintain a base line crankcase pressure.

years ago, with advent of chassis dyno's in most major truck engine repair facilities, manufactures gave out spec's on how to break in their engines,,, it didn't take 100 hrs.. and a listeroid that has been properly blueprinted should break in fully in under an hour or two at the most.

i vaguely remember the procedure, but i will research it and post it, rather than fall back on my memory

ah heck i will try it from memory... and then go see if i can find the info.

1. start the engine and apply approx 25% load run to normalize temperature,

2. log the crankcase pressure,,, in inches of water column

3. increase load until the water column starts to rise,,, log approx 2" rise

4. run engine at this load untill the column falls and stabilizes

5. increase load more and log at 2" rise,,,

6 run until the column falls,,

7. repeat until 100% load and stable water column

* reduce load if the column starts to rise at any point.

Mack truck used this method and published it in their overhaul manuals,,, i figure a listeroid in reality is 1/6 of a Mack.

now i gotta go see if i can find the procedure and see how far my memory is off,,, been approx 25 years since i read it.

bob g
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Doug

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Re: Breaking in a new engine
« Reply #4 on: August 15, 2006, 02:06:39 AM »
That's a very clever way of do it!

But can this be done on a thumper with that presure comming in single pulses?

Doug

mobile_bob

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Re: Breaking in a new engine
« Reply #5 on: August 15, 2006, 02:09:02 AM »
yes it can,,, but with a chamber sufficiently large to dampen the pulses

bob g
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mobile_bob

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Re: Breaking in a new engine
« Reply #6 on: August 15, 2006, 02:10:14 AM »
also there has to be an outlet on the chamber the same size as the crankcase fitting, or you blow all the water out of the column

bob g
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Rtqii

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Re: Breaking in a new engine
« Reply #7 on: August 15, 2006, 02:15:30 AM »
years ago, with advent of chassis dyno's in most major truck engine repair facilities, manufactures gave out spec's on how to break in their engines,,, it didn't take 100 hrs.. and a listeroid that has been properly blueprinted should break in fully in under an hour or two at the most.

You learn something new every day... Personally I suspected 10 hours for most of the seating... But I have not broken in a diesel before. My engine work has been limited to performance 2 & 4 cycle gas engines.

I agree about using a variable load and adding load... That is exactly the way to do it.

With your points in mind, it's clear to see that the first few hours of running are the most important. The idea of using a manometer is really interesting, but I wonder (like Doug) about the pulsing... Truck engines are multiple cylinder and generally run higher RPM, and because of the higher tolerances of U.S. manufactured engines for commerical transport I think there may be some variations... A Listeroid may take a few hours longer to settle in.

mobile_bob

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Re: Breaking in a new engine
« Reply #8 on: August 15, 2006, 02:35:25 AM »
a couple of notes worth mentioning

a detroit 2 cycle engine can be ruined if allowed to run without a load for more than 20 minutes after a rebuild,, the rings will glaze and it will always pump oil,,,

if you remove the cover and install one with a fitting to connect to a resevoir such as an old air tank, perhaps 5 gallon, and provide fitting not only to connect to the crankcase but also a fitting equal in size to the area of the original outlet,, you will fairly well dampen the pulses to an acceptable level, at least to a point of getting a relative reading on the manometer.

also an orifice can be installed in the manometer line to further reduce pulsations.

what you are after is a relative reading,, something to be able to see if the crankcase pressure is falling, rising or relatively steady,,, albeit pulsing,,, just average the highs and low's

say the best you can do is a pulsing between 2 and 4 inches of water,, you can assume an average of 3 inches, for the sake of the use that i described.

sure you could get anal about it, and work it down to a steady reading, but i don't think that is necessary.

for instance mid way thru the breakin the manometer goes up from 2-4 pulsing to 4-6, then reduce the loading a bit,, to get it back to the 2-4 pulse or nearly so..

seem reasonable?

bob g
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mobile_bob

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Re: Breaking in a new engine
« Reply #9 on: August 15, 2006, 02:52:37 AM »
also i would take a damn good look at the finish of the new cylinder as provided from india, before hand

unless i really liked it,, which i strongly doubt,, i would refinish it myself with a bead hone, to a finer finish, then clean properly.

by cleaning properly i mean the following

wash with solvent, or diesel, followed by

hot soapy water,, followed by

a thorough scrubbing with clean paper towels, (white) and engine oil, until the towels came out clean,, no sign of gray.

then and only then are they ready to be installed and well lubed with clean engine oil.

the same with the pistons, grooves, land ,, everwhere,

same with the rings,,  very clean

then if the gaps which should have been checked prior to cleanup are right ,,, assemble as normal.

i would also probably check my rings under magnification and prep them as needed.

if done properly breakin time is drasically reduced, and the engine life is greatly increased.

a note on valve jobs

i don't believe in lapping valves, if the valve job is done correctly with the proper angles, and interference angle closely adhered to, there is no need to lap them,,, lapping only reduces their wear life from what it would have been if they were done properly to begin with.

bob g
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Rtqii

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Re: Breaking in a new engine
« Reply #10 on: August 15, 2006, 03:09:08 AM »
a couple of notes worth mentioning

a detroit 2 cycle engine can be ruined if allowed to run without a load for more than 20 minutes after a rebuild,, the rings will glaze and it will always pump oil

Synthetic oil during break-in will also prevent rings from seating... Even if you stop using it, the rings will never seat properly.

europachris

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Re: Breaking in a new engine
« Reply #11 on: August 15, 2006, 12:35:12 PM »
a couple of notes worth mentioning

a detroit 2 cycle engine can be ruined if allowed to run without a load for more than 20 minutes after a rebuild,, the rings will glaze and it will always pump oil

Synthetic oil during break-in will also prevent rings from seating... Even if you stop using it, the rings will never seat properly.

That is false.  Many new auto engines today come from the factory with synthetic oils in the sump.  My VW Jetta TDI came with it, my wife's Liberty CRD diesel came with it, and I know the Corvette has come with factory Mobil-1 in the sump.  None of these engines have any trouble with break-in and my Jetta can go 10,000 miles between changes and use under 1/2 qt. of oil.

I'm not sure where this urban legend started regarding synthetic oil and break-in, but I keep hearing it and it keeps getting debunked.

Chris

bat outta hell

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Re: Breaking in a new engine
« Reply #12 on: August 15, 2006, 02:57:22 PM »
Synthetic oils in my opinion have no place i listeroids. My Mustang,Ranger,and Passport all get synthetic . My listeroids get only 30# non detergent.
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aqmxv

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Re: Breaking in a new engine
« Reply #13 on: August 15, 2006, 03:31:47 PM »
That is false.  Many new auto engines today come from the factory with synthetic oils in the sump.  My VW Jetta TDI came with it, my wife's Liberty CRD diesel came with it, and I know the Corvette has come with factory Mobil-1 in the sump.  None of these engines have any trouble with break-in and my Jetta can go 10,000 miles between changes and use under 1/2 qt. of oil.

I'm not sure where this urban legend started regarding synthetic oil and break-in, but I keep hearing it and it keeps getting debunked.

Chris

Apples and oranges.  All of the engines you cite are made with current OEM vehicle manufacturer standards for fit and finish.  These engines are designed with such good finishes and close tolerances that they are essentially 90-95% "broken in" the instant they're assembled.  The slight amount of burnishing of bores that happens in an engine designed after 1995 or so will happen with any oil, and isn't the big swarf-generating event of decades gone by.

Listeroids definitely qualify as older technology, and the older rules apply.  With old iron, break in is essentially the final machining operation in building the engine.  During break-in, coarse finishes on cylinder bore, crank journals, tappets and camshaft lobes are buffed smooth in an oil bath.  Accordingly, the oil in the sump needs to perform the functions of the oils used in machine shops duirng cutting, grinding, and honing operations on ferrous metals.  These oils are designed to have a specific (usually fairly low) film strength and a high detergency.  They're also applied voluminously so that they can perform their primary function as a coolant.  The designs (for critical machine work) usually also include a substantial amount of post-treatment to remove the entrained swarf before the lubricant is recycled through the machining process again.  If you can't do full-flow post-treatment of the oil, as we can't in a listeroid, you have to use a non-detergent oil so that the swarf will rapidly settle to the bottom of the sump and stay there before the oil is splashed back up onto the cylinder (or into the bearings) again.  Powerful magnets are obviously helpful for this process.

If the film strength of the oil is too high, it wil inhibit burnishing of the bore by the rings, or the rings will preferentially wear or flutter instead of burnishing the bore.  In this case, the bore and rings never conform to each other.  This can usually be fixed by changing to a lower film strength oil, applying a lot of load, and getting the engine hot.  Bon Ami has also been used with especially reluctant bores - sometimes by OEMs who don't want to scrap a large run of too-hard, but otherwise serviceable parts.  If the film strength is too low, excessive metal removal will occur, resulting in reduced run life. 

Rate of break-in desired is determined by the rate of metal being removed.  Machining generates heat.  Sure enough, a new engine runs hot.   How hot is determined by the rate of metal removal.  Get things too hot and the oil's viscosity decreases enough that the rate of metal removal increases again.  You get into a (bad) positive feedback loop.  Too high a rate of metal removal also exceeds ability the oil flow over the surfaces being machined to carry away the swarf.  Swarf starts hanging around and acting as an abrasive, which is also bad.  So there's usually a maximum desirable rate of break-in, which is determined by the ability to put clean oil on the bore to carry heat and swarf away.

The minimum rate of break-in is determined by the amount of combustion pressure required to force the rings into the bore hard enough to break the film strength of the oil and make machining happen.  The higher the film strength, the more load will be required.  At some point,  the oil is so good as a lubricant that it doesn't allow much machining at all, and the cross-hatch is never burnished out of the bore.  This results in the low-time "oil burning engine" of much mechanical lore.  Breaking in at a low RPM is bad as well - oil flow is reduced, which is always a bad thing.

There are lots of old mechanics' tales around that are true for something old enough, but false with newer designs and standards.  This is a good example.  I would never run non-detergent single grade oil in a new car.  I would also never run a multi-viscosity synthetic during break-in of a Model T, a Listeroid, or a stovebolt Chevy.
« Last Edit: August 15, 2006, 03:34:13 PM by aqmxv »
6/1 Metro IDI for home trigen

mobile_bob

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Re: Breaking in a new engine
« Reply #14 on: August 15, 2006, 03:47:59 PM »
europachris:

careful how you drag your quotes,,,, it looks like the couple of things belong to me,,, when in reality only one does

that is the detroit

detroits will be ruined in as little as 20 minute of run time with no load,,, after overhaul.

source 30 years experience and Detroit Diesel Allison

a detroit will not build any heat if allowed to run at idle speeds and no load, thus will glaze up, and pump oil

bob g
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