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| What is the correct method for engine "break-in"? |
| It doesn't matter. "Break-in" is less important than correct assembly. |
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| Traditional gentle "run-in" at varying rpm for the first 2,000 miles. |
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50% |
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| Very brisk operation at varying rpm for the first 1,500 miles. |
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37% |
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| Run it like you stole it! |
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| Total Votes : 8 |
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Sanctifier
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Sanctifier
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Joined: 07 Apr 2005
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Location: Good question!
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 Posted: Thu Sep 17, 2009 5:18 am Post subject: |
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| 2nr wrote: | Which Oil do you recommend to break in Piston Rings? Something Non Detergent...
I need the rings to seat, so something non detergent would work for me.
which oil sold locally has these properties? |
Something Non Detergent... Why non detergent??
During "break-in" period, even more swarf (chips, etc.) is dislodged than normal. Detergent additives will help to dislodge them from the block's surfaces and allow them to be removed more easily.
Accurate Oil info here... Link--> The Truth: ~ About Oil... and the BULLSH!T about it.
| Sanctifier wrote: | Common Myths About Engine "Break-in" Proceeedure:... Expert recommendations below each.
 Something Non Detergent...
[For the "Break-in" period, use a high quality, MINERAL based, MULTIGRADE oil ONLY!]
the best way to break-in an engine is to moderately accelerate to 5000 rpm while driving...
[DO NOT START/RUN your rebuilt/new engine AT LOW IDLE SPEED in your garage 
IMMEDIATELY after "warm-up", (@ brisk & fluctuating "off-idle" speed: 1,500-3,000 rpm)...
Accelerate BRISKLY & REPEATEDLY TO "RED-LINE" of your engine (AND BACK TO LOW RPM) for the first 20-30 miles... then CHANGE oil & filter for the 1st time...
Two more changes to go. Don't extend period between 1st two changes. That oil contains the MOST swarf.]
with the non-detergent oil, the rings would seat faster and better... more friction against the walls...
[Higher piston-ring pressure on the cylinder wall is obtained from higher combustion pressure (more "load" ie. acceleration) not from a lack of adequate (non-detergent) lubrication. See links.]
detergent oil will wash away the little particles in the oil that help break in the motor...
[What little particles? See links attached.] |
BTW this is not my opinion. These are recommendations from Engineers/Developers/Testing Labs. like David Vizard...AMS...Dave Buschur...Pat McGivern...Consumer Reports... and The American Petroleum Institute.
For their recommendations on type of oil to use, length of usage and correct method of breaking in a rebuilt/new engine, see 1st links above.
THEIR $0.02¢ 
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Sanctifier
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| Posted: Fri Sep 18, 2009 6:13 am Post subject: |
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| 2nr wrote: | | Which Oil do you recommend to break in Piston Rings? |
This article is about aeroplane engines. The SAME thing applies here... [ used for emphasis.]
| Quote: | Suggestions for Proper Engine Break-In.
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Whenever an engine's piston rings are replaced whether in part or in entirety it is necessary to break in the engine. Piston rings are replaced at a complete engine overhaul or repair, top overhaul or single cylinder overhaul or repair.
When we refer to engine or cylinder break in, we are talking about the physical mating of the engine's piston rings to it's corresponding cylinder wall. That is, we want to physically wear the new piston rings into the cylinder wall until a compatible seal between the two is achieved.
Proper engine break in will produce an engine that achieves maximum power output with the least amount of oil consumption due to the fact that the piston rings have seated properly to the cylinder wall. When the piston rings are broken in or seated, they do not allow combustion gases to escape the combustion chamber past the piston rings into the crankcase section of the engine. This lack of "blow-by" keeps your engine running cleaner and cooler by preventing hot combustion gases and by-products from entering the crankcase section of the engine. Excessive "blow-by" will cause the crankcase section of the engine to become pressurized and contaminated with combustion gases, which in turn will force normal oil vapors out of the engine's breather, causing the engine to consume excessive amounts of oil.
In addition to sealing combustion gases in the combustion chamber, piston rings must also manage the amount of oil present on the cylinder walls for lubrication. If the rings do not seat properly, they cannot perform this function and will allow excessive amounts of oil to accumulate on the cylinder wall surfaces. This oil is burned each and every time the cylinder fires. The burning of this oil, coupled with "blow-by" induced engine breathing, are reasons that an engine that hasn't been broken in will consume more than its share of oil.
When a cylinder is overhauled or repaired the surface of it's walls are honed with abrasive stones to produce a rough surface that will help wear the piston rings in. This roughing up of the surface is known as "cross-hatching". A cylinder wall that has been properly "cross hatched" has a series of minute peaks and valleys cut into its surface. The face or portion of the piston ring that interfaces with the cross hatched cylinder wall is tapered to allow only a small portion of the ring to contact the honed cylinder wall. When the engine is operated, the tapered portion of the face of the piston ring rubs against the coarse surface of the cylinder wall causing wear on both objects. At the point where the top of the peaks produced by the honing operation become smooth and the tapered portion of the piston ring wears flat break in has occurred.
When the engine is operating, a force known as Break Mean Effective Pressure or B.M.E.P is generated within the combustion chamber. B.M.E.P. is the resultant force produced from the controlled burning of the fuel air mixture that the engine runs on. The higher the power setting the engine is running at, the higher the B.M.E.P. is and conversely as the power setting is lowered the B.M.E.P. becomes less.
B.M.E.P is an important part of the break in process. When the engine is running, B.M.E.P. is present in the cylinder behind the piston rings and it's force pushes the piston ring outward against the coarse honed cylinder wall. The higher the B.M.E.P, the harder the piston ring is pushed against the wall. The surface temperature at the piston ring face and cylinder wall interface will be greater with high B.M.E.P. than with low B.M.E.P. This is because we are pushing the ring harder against the rough cylinder wall surface causing high amounts of friction and thus heat. The primary deterrent of break in is this heat.
Allowing too much heat to build up at the ring to cylinder wall interface will cause the lubricating oil that is present to break down and glaze the cylinder wall surface. This glaze will prevent any further seating of the piston rings. If glazing is allowed to happen break in will never occur. We must achieve a happy medium where we are pushing on the ring hard enough to wear it in but not hard enough to generate enough heat to cause glazing. If glazing should occur, the only remedy is to remove the effected cylinder, re-hone it and replace the piston rings and start the whole process over again.
Understanding what happens in the engine during break in allows us to comprehend the ideas behind how we should operate the engine after piston rings have been changed. The normal prescribed flight procedure after ring replacement is to...
keep ground running to a minimum... [Like our "NO IDLE Rule" to PREVENT HEAT build-up and GLAZING.]
take off at full power... [Like our Wide-Open-Throttle to "Red-line" for MAXIMUM BMEP.]
reduce to climb power at the first available safe altitude... ... (Like our DECELERATION phases during "closed throttle" operation for lower BMEP and thus optimum COOLING.)
All while keeping the climb angle flat and the climb airspeed higher to promote the best cooling possible.
At cruise altitude we should use 65% to 75% power and run the engine richer then normal... ... (Richer Mixture = Less BMEP = Less Power = Lower Exhaust Gas Temperature = More ENGINE COOLING.)
At all times we are to remember that heat is the greatest enemy of engine break in, we should try to maintain all engine temperatures in the green, well away from the top of the green arc or red line.
This means step climbing the aircraft if necessary... [Like our Wide-Open-Throttle to "Red-line" for MAXIMUM BMEP.]
operating with the cowl flaps open or in trail position during cruise flight...
... (Like our DECELERATION phases during "closed throttle" operation for lower BMEP and thus optimum COOLING.)
being generous with the fuel allocation for the engine... ... (Richer Mixture = Less BMEP = Less Power = Lower Exhaust Gas Temperature = More ENGINE COOLING.)
We should not run the engine above 75% power in cruise flight because the B.M.E.P is too great and the likelihood of glazing increases. As you can see, keeping the engine as cool as is practical and at a conducive power setting is the best combination for successful engine break in.
After an engine is overhauled or has a major repair it is run in a test cell (~ engine dyno) to ensure operating characteristics and to begin the break in process. However this process may take as long as 100 hours of operation to complete. You, the pilot, are in control of engine break in for 98 % of the time that it takes to occur. This is a serious responsibility when you consider the expense and aggravation of having to remove, re-hone and re-ring cylinders that have glazed and not broken in.
Hopefully, understanding what engine break in is, as well as what is happening in the engine while the rings are seating and how our flight procedures effect the break in process, will help us to achieve the quickest and most efficient break in after piston rings are replaced.
by Mahlon Russell... [email protected] |
Link--> Suggestions for Proper Engine Break-In.
THEIR $0.02¢
| Sanctifier wrote: | "HEAT is the greatest enemy of engine "break in"... and Oil's most important function is a COOLANT!
IMHO reducing the oil's friction modifiers, obviously increases FRICTION which will INCREASE temperature... increasing the risk of GLAZING... which REDUCES optimum ring-to-wall "sealing"... and increases "BLOW-BY" and oil consumption.
As far as "grade" is concerned, IMHO use a MINERAL, Multigrade that's similar to your OEM's recommendations...
They know their engine's bearing clearances best.
HOW you perform the "break-in" is more important. (See above.)
Correct "break-in" = HIGHEST BMEP @ OPTIMUM Temperature = MAXIMUM Durability & HIGHEST Torque & Power. |
My $0.02¢ 
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Sanctifier
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| Posted: Fri Sep 18, 2009 6:59 am Post subject: |
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| 2nr wrote: | | Santifier, with all due respect to you, this is what I am saying all along, use your manufacturer specific recommeded oil in non-synthetic formula. The difference with aircraft and automobiles however is vastly different. Aircraft fly hours and hundred of miles in one trip, where as the automobile distance can be easily control, therefore to speed up the break in process, using an oil with less friction modifier will result in shorter break in time. (Key word -Less friction modifier) and not no friction modifier. In any case all rebuilt engine operate at a slighly higher tempereture because of BEMP irregardless of what engine oil is used. |
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Sanctifier
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| Posted: Fri Sep 18, 2009 7:00 am Post subject: |
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Yup, I understand..."the reduction (not elimination) of friction modifiers." No argument there at all.
However, what I am concerned about is the fact that while usage (running hours) may differ... the capacities and RPM ranges of our engines are also widely different as well. RPM fluctuation is also greater for us than the nearly constant RPM of planes at crusing altitude (for greater fuel economy.) So less HEAT... and therefore longer "break-in" period for them.
In addition, won't Turbocharging also tend to make Peak Exhaust Gas Temperature even higher because of higher Specific BMEP/litre? Even more so at higher ambient temperature, (ground level) in our smaller, high-rpm engines?...
Therefore, with our higher temperatures, then maybe the HEAT caused by extra FRICTION at higher RPM, makes the reduction (not elimination) of friction modifiers less of an issue for us??? Even for no other reason than to reduce the risk of GLAZING??
This is NOT an argument... You obviously know more than I do, about this issue.
I really would appreciate some feed-back on this. Thanks a lot.
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VK-Sportsman
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| Posted: Fri Sep 18, 2009 5:15 pm Post subject: |
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*bookmarked*   
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Sanctifier
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| Posted: Sun Dec 18, 2011 5:35 pm Post subject: |
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| Sanctifier in another place wrote: | Since the most important issue of initial "run-in" is "PISTON RING SEALING" then (since a chassis dyno is not available to most people) the most practical method seems to be:
1) Use a MINERAL oil for initial run-in... (1 1/2-3 miles.)
| Quote: | | "The jury is still out" on this but I'll err on the side of caution and follow this recommendation. |
2) NO high load or hard running when cold, so "warm up" to normal operating temperature... AND DRIVE BRISKLY a.s.a.p.
| Sanctifier wrote: | re. "30 minutes of moderate fast idle to warm things up"... I'm afraid I disagree.
This will risk piston-ring "glazing" and reduce ring sealing... NOT what you want to do!
 To REDUCE the "warm-up" period even further and reduce the risk of "ring glazing"...
Why not fill the radiator and engine with HOT WATER before starting a "new" engine for the 1st time? |
3) NO sustained period at constant throttle or constant RPM.
4) No bashing the rev limiter... but DRIVE IN 1st and 2nd gear (to stay within the Speed Limit and avoid a ticket!) for approx. 3 miles.
5) Try to rev to "red line" and then decelerate in gear as frequently as possible for the initial run-in (3 mile) period.
The idea is to "load" the rings (combustion pressure) as much as possible so that they wear i.e "bed" with cylinder walls to maximize sealing... and "unload" (during closed throttle deceleration) to avoid "glazing" and unnecessary wear.
Decelerating "in gear" helps to INCREASE the time available under partial vacuum (closed throttle)... for a longer period than can be achieved when not "in gear".
6) CHANGE your oil AND filter immediately!... to remove metal swarf. |
My $0.02¢
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Sanctifier
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| Posted: Sun Dec 18, 2011 6:35 pm Post subject: |
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UPDATE: These tips from AMS are VERY important. Ignore them at your peril
| AMS wrote: | If you have had an engine failure such as a spun bearing or any other failure; your ENTIRE oiling system has been contaminated with metal shavings. Metal debris from engine failure will RUIN your new engine!
Most items can be cleaned out such as the oil pan etc… but you CANNOT clean out your oil cooler enough to be re-used. No amount of cleaning will get all of the debris out. Please perform the following steps when installing your new engine:
1. Replace the engine oil cooler: This is the most important step of all. Oil coolers CANNOT be flushed out completely. You can never get all of the debris out of the internal fins of the oil cooler. The OEM EVO oil coolers are very expensive; AMS offers an aftermarket/upgrade oil cooler for a very reasonable cost.
2. Clean out the cylinder head: Bring the cylinder head to a reputable machine shop, explain your engine failure and have them inspect and clean the cylinder head.
3. Clean everything in the oil system: Thoroughly clean all engine oil system parts that you don’t replace (oil pan, dipstick tube, oil filter housing, oil pickup tube, etc...)
4. Flush out the turbo: Once the engine is installed disconnect your crank sensor to disable the engine from starting. Remove the oil return line from the turbo and fill the crank case with fresh oil. Crank the engine allowing oil to drain from the turbo until clean oil comes out (roughly 2 qts.). Be careful not to run the engine out of oil while doing this. Connect oil return line to turbo when done.
*
5. Priming your new engine before start up: Your new engine must be primed with oil before start up. Fill your engine with fresh oil to full level on the dipstick.
With the crank sensor still disconnected crank the engine until the oil light on your dashboard turns off, this means you now have oil pressure and are ready to start your new engine.
Connect the crank sensor and start the engine. Carefully monitor oil pressure.
If oil pressure is low or the oil light comes on immediately shut off the engine. |
| Sanctifier wrote: | * I would fill the engine & cooling system with HOT Water AFTER Step #4... and BEFORE Step #5 to encourage as much "pre-start" cylinder head & block expansion as possible. That way, the engine stays for a SHORTER time at a brisk & fluctuating idle (1,200-2,500 rpm?) before proper engine "warm-up" is achieved.
NOW---> CANE IT! ("to Red-line" as described above)... "in-gear" for about 3 miles.
THEN do your 1st Oil Change a.s.a.p. |
As they say... A word to the wise is sufficient!
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Sanctifier
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| Posted: Sun Dec 18, 2011 6:38 pm Post subject: |
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| VexXx 2nr wrote: | ...it was mentioned to use 10-40 mineral.
Any preferred brand of oil for this initial break in? |
preferred brand... Depends on the engine used and modifications done. IMHO check with product manufacturer first.
For instance, a normally aspirated 4-banger revving to 7,000 rpm (w/ "street" cam & making < 180-200 lb/ft torque @ flywheel) will be less "picky" than a well modified engine. eg. Evo 4G63 with 450+ lb/ft WTQ & going to 8,000+ rpm.
It also depends on which "add-ons" are used... eg. if you use an FP Red/Black turbo on that same Evo 4G63 engine then you MUST use an oil that's high in zinc & phosphorus high pressure additives... Yup, IMHO even for a 3-mile "break-in."
Link--> Forced Performance Recommendations for Motor Oil.
My $0.02¢
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